ARCHIV AL REPORT

Proceedings

of the

Training Workshop for

Downy Mildew Control

INTERNATIONAL INSTITUTE OF TROPICAL AGRICULTURE

ARCHIVAL REPORT

Proceedings of the Training Workshop for Downy Mildew Control

Federal College of Agriculture, Akure 17-19 May 1994

Editors

K.F. Cardwell, V.O. AdenJe, T.O. Adenola NIGERIAN DOWNY MILDEW TASKFORCE

INTERNATIONAL INSTITUTE OF TROPICAL AGRICULTURE

Contents

Introduction

State ADP Reports

Kwara State Kogi State Oyo State Osun State Ondo State

Technical Papers

Know the Enemy-A Control Strategy Against the Biological Weak Points of Peronosclerospora sorghi

Symptoms of Downy Mildew Disease of Maize Caused by Peronoscierospora sorghi

Evaluation and Multiplication of Maize Varieties

The Current System of Commercial Seed Production

Chemical Seed Treatment

Seed Certification Regulations in Nigeria

Logistics of On-farm Testing for Downy Mildew Eradication

Extension Communication

Working Group Presentations

Status of Downy Mildew Resistant Seed Requirement, Production, and Distribution Outlets by State

ADP Seed Production Projections for 1996

Maize Seed Production Cost/Ha

Page

3

4 6 8

10 11

12

14

16

26

32

35

42

45

49

50

51

Working Group on Seed Distribution Mechanisms in DM Affected States 52

Logistics of On-Farm TestinglField Days 53

Campaign Communication Messages in Print and ElectroniclMedia 54

Extension & Training Personnel and Technical Messages 55

Budget for Extension, Training & Communication 57

Summary of Downy Mildew Control Mildew Campaign Budget by State 60

List of Participants 62

2

Introduction

An international conference and workshop on the control of the downy mildew disease of maize was held in February 1994 at the International Institute of Tropical Agriculture (lIT A), lbadan, Nigeria. The conference was sponsored by lIT A, the Food and Agriculture Organization (FAO) of the United Nations, the Nigerian Federal Department of AgriCUlture, and organized by the Nigerian Downy Mildew Task Force (DMTF). The objective of the one-day conference was to present information about the extent of the threat. of downy mildew to maize production in various countries of sub-Saharan Africa, and to sensitize donors to this threat. The objective of the two-day workshop which followed the conference was to use the case of Nigeria, where severe losses in maize production due to the disease were being experienced, as a model for developing a control campaign that would result in the eradication of the disease.

In Nigeria, the February conference and workshop at IITA were considered the kick-off for a national campaign to control downy mildew disease. To organize the details and logistics of the up-coming campaign in Nigeria, DMTF organized a training workshop which was held in the Federal College of Agriculture, Akure from 17 to 19 May 1994. Participants from private chemical and seed industries, research institutes, the National Seed Service, and senior officers of the six state agricultural development projects (ADPs) attended the workshop (see annex 1 for attendance and representation). The officers included section heads of seed, commercial, communication, extension, and women in agriculture divisions from each of the states: Edo, Kogi, Kwara, Ondo, Osun, and Oyo. In all, there were 54 people in attendance.

Technical training lectures were presented by experts in the fields of plant pathology, plant breeding, seed production, seed treatment, extension, and communications. State ADPs presented the most current data about maize production per state. Then the workshop split into working groups to hammer out details about seed production costs and requirements, extension goals and budgets, logistics of on-farm trials, and technically accurate communications messages with per state costing for production.

The information generated by the Akure workshop is presented in these proceedings. The data found here will be useful to the states as they plan their work each year. It is also an important data base against which progress can be measured. Finally, it may serve as an example of how government and private agricultural sectors can, and must, work together for a specific goal such as controlling a crop disease like maize downy mildew on a regional level.

3

Maize Downy Mildew Disease Workshop: Kwara State Report

E.O Aje

Extension Goals

1. Create awareness of this disease and its control methods. 2. Stimulate interest on how to prevent the disease and the control measures available. 3. Employ small plot adoption technique (SPA 1) on maize, using DMR varieties. (Each

extension agent (EA) has about 30 SPATs. There are 122 EAs and 21 block extension agents (BEAs) now).

Budget

Radio

(i) Jingles in 3 languages: Yoruba, Battunu, and Nupe

Production cost = N5,265/jingles x 3 languages = N15,795

(ii) Airing time

Period: May-August = 16 weeks Airing rime/week = 6 times No. of languages = 3 Cost per slot = N350

Production cost'" 16 weeks x 6 times/week x 3 languages x N350/slot '" NlOO,800

(iii) 4 radio cassettes at N45@ for the jingles on mobile video vans'" N180

Production cost'" N15,795 + Nl00,800 + N180 '" N116,775

Posters

(i) Languages Nupe--l000 posters

Battunu-IOOO " Yoruba-3000 "

5000 posters x N8/poster '" N40,OOO

(ii) Posting of bills

N50 EA x 225 EAslBEAs '" Nl1,250

Production cost'" N40,OOO + N 11,250 '" N5l,250

Use of Mobile Video Shows (i) Fuel and maintenance '" N2000/vehicle x 4 weeks

Vehicles x 4 '" N32,OOO

(ii) Allowance for mobile video supervision 4 supervisors x 20 working day x N200/day x 4 months'" N64,OOO

(iii) Allowance for mobile video van drivers 4 drivers x 20 working days/month x 4 months x 100/day '" N32,OOO

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(iv) Allowance for zonal extension oficer's supervision tours 4 days/month x 4 months x N200/day x 4 ZEOS = N12,800

Production cost for mobile video show = N32,OOO + N64,OOO + N32,000 + N12,800 = Nl40,800

Production of Extension Guides on Control of Maize Downy Mildew Disease

3000 copies at N5 @ = N15,OOO

Total = N116,775 + N5l,250 + Nl40,800 + N15,000 = N323,825

Constraints

Fuel shortage and lack of funds are our biggest problems. As a matter of fact Kwara State ADP (KW ADP) is not sure if World Bank funding will continue beyond 30 June 1994 because of poor counterpart funding.

Projected Seed Requirements: Possibilities and Constraints

At present we have procured 33.072 tonnes of resistant maize seed from our outgrowers in addition to 2.03 tonnes from the seed farm and intended tonne of hybrid seeds. Although this quantity looks small, it is dictated by our past sales experience. For instance last year we were only able to sell about 37.5 out of about 56 tonnes of unsold seeds.

Generally, the constraints to sales of ADP seed are: 1. High cost of imprOVed seeds per kg. 2. The farmers' preference to use their own susceptible seeds albeit treated with Apron Plus® rather than the resistant seeds. The reason for this is partly that these susceptible seeds, e.g., Farz 34 are more high yielding than the resistant varieties. 3. The problem of farmer-saved seeds. The farmers select seeds from their farms at apparently no cost to them. So they do not come back to buy from the ADP after the initial purchase of seeds of the new variety. Surprisingly, it seems the National Seed Service is encouraging this. We may therefore expect this practice to increase with this official approval.

Current Levels of Preparedness

We have stocked and started distribution of downy mildew-resistant maize. In Kwara State, since the outbreak of this disease, we have been distributing only resistant maize seeds to farmers. Similarly we have 23,000 satchets of Apron Plus® which we have also started distributing.

For di'stribution, we use the normal commercial service department's sales outlets. To complement this, we have started mobile sales usually during campaigns. Finally, we have been distributing seeds and Apron Plus® through tested extension agents (TEAs) and block extension supervisors (BESs). However, these effons are being hampered by shortage of fuel The MANR is also involved in the distribution of Apron Plus® received from the Federal Government at headquarters and its area offices.

We have commenced campaigning with mobile video shows. Again fuel shonage is a constraint here. We have aired two radio and two television programs on the disease, but the planned radio jin~les have meanwhile been suspended due to lack of funds. We have extension guides to four languages-English, Yoruba, Nupe, and Battunu-although we need to produce more.

5

Downy Mildew of Maize: A Situation Report from Kogi State

A.B.Olumo

Introduction

Downy mildew on maize has been reported in Kabba and its environs in Kogi State since about 1975. The spread had been very gradual until 1989/90 when it spread to many local government areas in the former Kwara State. Now, the disease is found in all local government areas along the western flank of the River Niger in Kogi State. Meanwhile, only pockets of reports of its occurrence are being received from the eastern segment (formally Benue State).

Up till last year, yield losses of up to 60% and above on infested farms were experienced in areas of the state where the disease is endemic.

Strategies Adopted by Kogi ADP to Eradicate Downy Mildew

Extension. There are 133 e)(tension agents (EAs), and block extension agents (BEAs) who carry extension messages to farmers. Since the beginning of the year, they have been vigorously educating farmers on farm sanitation, the use of downy mildew-resistant varieties of maize, and the use of Apron Plus® to dress maize seeds.

All maize-based SPATs (small plot adoption technique) are, of necessity, resistant varieties of maize. A total of 8,835 maize-based SPATs are expected to be used this year as shown below.

Officers No. staff Total maize-based in the state Spats

Extension agents 114 1,980 (EAs)

Block extension 19 855 agents (BEAs)

Total 133 8,835

In August 1993, well-attended field days were organized by Kogi ADP at the peak of the occurrence of the disease. Similar field days were planned in 1994.

For wider publicity, there are radio and television broadcasts on the need for farmers to use imprOVed (resistant) seeds and seed-dressing chemicals from Kogi ADP.

Research

On-station research: A trial on downy mildew-resistant varieties versus sowing dates is being carried out in five locations in the state. On-farm adaptive research: A trial to be carried out in the farmers' fields to convince them of the effectiveness of Apron Plus® on downy mildew has been designed. This will be carried out in 40 locations in the state. It is hoped that this will help to futther popularize the use of Apron Plus® seed dressing.

Seed Multiplication

The seed department multiplied about 40 tonnes of downy mildew-resistant varieties of maize last year through outgrowers. This year, plans are on to multiply an equal amount. In fact, no susceptible maize varieties will be multiplied at all this year. To ensure high quality of OUT cenified seeds, all OUT maize foundation seeds always comes from the National Seed Service (NSS).

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Commercial

Procurement and sales of seed took off this season with about 3.5 tonnes of downy mildew­resistant maize varieties bought from outgrowers. The same quantity has been dressed with Apron Plus® and distributed to all sixteen farm service centers in the four zones of the ADP. More resistant maize seeds will be bought when funding improves. In all, there are currently less than 300 satchelS of Apron Plus® in the various farm service centers. As soon as funding improves, more Apron Plus® will be procured.

7

Report by Oyo State ADP on Campaign for Downy Mildew Disease Control

I.K. Agigun

Although downy mildew disease of maize filtered into Ogbomosho and Ibadan zones of Oyo State in 1992 through Kwara and Osun states respectively, the history of the campaign for its control dates back to 1991. This is predicated on the fact that Desa and Osogbo, where the deadly disease first assumed epidemic proportions, were still part of the old Oyo State.

A number of on-station and on-farm trials were designed and conducted by the Technical Services Department to verify the resistance ofDMR maize varieties and determine the economic but effective dose of Apron Plus® for seed dressing. The seed multiplication scheme for DMR maize varieties was also initiated on ADP seed farms. By 1992, the scope of DMR seed multiplication was widened with the appointment of contract growers for that purpose. The distribution of the DMR variety and of Apron Plus® as seed dressing for maize began that year.

A jingle on radio was recorded in 1992 and aired for three months to educate farmers on identification, symptoms, effects, and preventive measures of downy mildew disease of maize at the rate of one transmission per day for three months.

By 1993, the disease had spread to Oyo zone, leaving only Ibarapa sector of Ibadan zone, and the entire Shaki zone free. The radio jingle was again sponsored that year at the rate of two transmissions per day for five months at a cost of NI05,OOO. Relevant topics were developed for transmission on radio and television while appropriate messages were developed into playlets for Village Drama. About 5,000 leaflets and 10,000 posters on downy mildew were also printed and distribuled to all categories of extension staff as well as farmers allover the state.

Using the appropriate mechanisms for tlte training feature of the Training and Visit (T & V) Extension, topics on downy mildew disease of maize were incorporated into the lesson plans and imparted to extension staff at FNT sessions. Photographs of infected maize plants at various stages were also taken for display at the FNT centers across the state to serve as visual reference materials. All front-line extension agents were equipped with a satchet of Apron Plus® to reinforce their training to farmers at the field level.

SPAT was also established to backup field training offanners: 2,152 plots of downy mildew cum streak resistant variety of maize, and 2,002 plots of seed dressing of maize using Apron Plus®.

1994 Proposals

Subject to availability of funds, the radio jingles will be sponsored again, while relevant messages will also be transmitted on radio and television and developed into playlets to be staged on Village Drama.

About 5,000 copies each of leaflets and posters will be printed and distributed to cover more farming families. Existing mechanisms will be employed to intensify awareness training of farmers.

SPAT messages have also been proposed, 3,540 plots in either case of "Introduction of downy mildew or streak resistant variety of maize" as well as "Use of Apron Plus® for seed dressing". The policy of equipping every EA with a satchet of Apron Plus® as back suppon for farmers' training will be maintained. The documentary on this deadly maize disease already produced will be shown to farmers this year during Farmers' Field Day.

We have agreed to establish ten demonstration plots across the state to be located as follows:

Ibadan zone, 3 plots: Oluyole and Egbeda (Ibarapa LOA)

Ogbomosho zone, 2 plots: Ogo Oluwa (Surulere LOA)

Oyo zone, 2 plots: Iseyin (Oyo LOA)

Shaki zone, 3 plots: Ifedapo and Orelope (Kajola LOA)

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We have also proposed to stage 35 fanners' field days at block level. In addition, we are proposing two large field days in Ibadan representing the forest ecology, and Ogbomosho representing the savanna ecology. It is hoped that these would enable participating fanners to visit some of the demonstration plots.

Also, 75 tonnes of seed from different varieties of maize available with the ADP technical services department will be pushed to farmers this year, while the size of the 1994 DMR maize seed multiplication project stands at 40 ha (10 ha by direct production on program seed fanns, and 30 ha by outgrowers).

9

Current Levels of Preparedness for the Up.Coming Growing Season and Downy Mildew Control Campaign in Osun State

S.O. Odebumi

Since the first repon of downy mildew in Osun State in July 1990, concened effons have been made to control its menace in the state. Some of the efforts are enumerated below: 1. SPAT plots of DMR maize were set up in the endemic areas to demonstrate to farmers that certain maize seeds could escape the disease.

2. OFAR trials were set up to test the efficacy of Apron Plus® in protecting maize plants when used at the recommended rates.

3. Field days were organized to educate farmers on ways of combating the deadly disease. This was done on a block basis in the endemic zones of Ife-Ijesa and Osogbo.

4. About 15 [onnes realized from the 10 ha ofDMR varieties multiplied in 1991 were injected into the endemic areas in the 1992 planting season.

5. In 1992, 104,865 sachets, (1048.65 kg) of-Apron Plus® were sold to farmers in Osun State and used to treat approximately 209,730 kg of seeds which could plant 8,389.20 ha of farmland.

6. A 17 tonne package of maize seed was distributed to farmers throughout the state in 1992. More than 800 farmers benefitted statewide.

7. Between 60 and 65% of the 58,253 ha (both early and late crops) under maize cultivation in 1993 were planted with DMR maize seeds.

OSADEP had 591.99 kg of Apron Plus® at the beginning of 1994 for the planting season and got an additional 150 kg from the Federal Government, bringing the total to 741.99 kg. The department sold a total of 158.38 kg in 1993. The 8,000 kg of Apron Plus® ordered through lCB 2 for 1994 is still expected.

The Extension department has started mounting a campaign on the use of Apron Plus® and downy mildew-resistant maize varieties by farmers. The department is also planning to organize field days on a block basis later in the year.

With these efforts, it is hoped that the menace of the disease will be brought below economic threshold levels by the end of the year.

10

Report of On do State ADP on Downy Mildew Disease of Maize

G.N. Bouraima

Ondo State ADP began its campaign against DM disease of maize in 1989. In preparation for the eradication of DM, the ADP has been running two programs each on radio and television.

The extension sub-program has been involved in OFAR and SPAT trials on farms of contact farmers to promote the downy mildew-resistant varieties of maize: DMESR-Y DMLSR-W & Y, and lately, SUWAN I. During the 1994 cropping season alone 700FAR trials and over 3,000 SPAT plots were established with downy miidew. This contact farmers' approach, which is aimed at ensuring a multiplier effect, has brought about a very high rate of adoption of the resistant varieties of maize by farmers.

However, the state will not relent in its efforts to ensure effective, controlled eradication of the disease through on farm trials, farmers' field days, and mass media campaigns.

To this end, the seed multiplication and quality control units of Ondo State ADP supplied seeds and planted 28 hectares of DMR varieties of maize. In addition the seed industries development arm of the FDA sent 2 tonnes of EV 8843 DMR-W for distribution to small scale farmers in 1994.

All these were pushed to the grassroots farmers in an effort to control downy mildew disease.

The farmers' field day will be held on 3 November 1994. In all, over two hundred farmers from 6 zones will participate in the field day. Experts from NAERLS, UTA, Ciba Geigy, etc., are also expected. The participating farmers will be conducted round four downy mildew infested areas around Oba-fie.

The ADP communication support unit produced the following papers: 2,000 extension guides (Yoruba and English) 2,000 extension leaflets (Yoruba and English) SOD posters (Yoruba)

Copies will be distributed during the field day and the others will be distributed to other farmers before the next planting season.

11

Introduction

Know the Enemy-A Control Strategy Against the Biological Weak Points of Peronosclerospora sorghi

K. F. Cardwell IlT A. lbadan

Data from 1991 show that losses to downy mildew of maize in Nigeria cost the nation's fanners close to N3.5 million (Adenola et al. 1991). Kwara State alone lost 40% of its production to this fungal disease. Once a plant becomes infected, the tassel and ear will not develop normally. so that the infected plant will produce no cob. Fields with up to 80% infection are not uncommon in the states where downy mildew is endemic. This 80% infection translates into an 80% loss of production.

This loss is too high. This disease is causing economic and physical hardship to the rural communities of this country. With this workshop. we are beginning a campaign to push this pathogen out, hopefully to the point of eradication. Like a military campaign to push back an enemy, it will be necessary to have a strategy consisting of several tactics to control this enemy. This strategy must be developed based on knowledge about the strengths and weaknesses of the enemy. Fortunately, Peronosc/erosopra sorghi, the enemy, has many biological weak points.

Biological Weak Points of the Downy Mildew Pathogen

• Peronosc/erospora sorghi, is an obligate parasite. i.e., it cannot survive if it is not on a living host plant.

• No hosts other than maize have been identified in the southern endemic states where the disease is causing the most loss.

• No overseason survival structure (oospore) has been identified in the maize strain of this pathogen.

• The pathogen can only infect plants that are less than 30 days old, have a susceptible genotype. and are unprotected chemically.

• The spores that cause infection (the conidia) are so delicate that they do not survive more than 30 minutes after they have matured.

• For sporulation (conidiation) to occur, nighttime temperatures must drop to 20-21oC, and

dew must form so that the surface of the leaves are moist.

• For infection to occur. the newly fonned conidia must dislodge, and be carried by air currents to land on a young, susceptible host plant before the conidium dries out.

Biological Strengths of the Downy Mildew Pathogen

• In areas where maize is cropped cOnlinuously with susceptible varieties, including fadarna plantings during the dry season, the pathogen has the opportunity to survive. because it can always drop on a young host plant and cause a new infection.

• Within ten days of a plant becoming infected, the pathogen begins to produce new conidia on the newly infected plant.

• Neighboring plants in the same field can become infected until they are 30 days old.

• The DM pathogen does not kill the host plant that it infects. it allows it to continue to grow while it continues to produce conidia in the infected tissue.

• Thousands of conidia can be produced on one infected plant.

• The conditions for conidial production occur frequently in the humid savanna and forest zones, even during the dry season in fadamas.

• The conidia can travel long distances in wind especially during moist nights.

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• Conidia and mycelium may move in green plant parts from zones where the maize is infected to zones where the maize is healthy.

Strategy Development

Keeping in mind the strengths and weaknesses of the downy mildew pathogen, a strategy must be developed which exploits the weaknesses, and undermines the strengths of the enemy. First of all, the environmental conditions of the endemic zones and the continuous cropping systems cannot be easily changed. Maize is cropped year round in areas where the disease is a problem. The weakest point occurs during the dry season when the only maize grown is in small plantings in the fadarnas. What would happen if all of the maize planted during the dry season were resistant or treated with an effective seed dressing? What would happen if the farmers rogued the infected plants from the fadama plantations? The disease would be eradicated. There would be no new conidia to infect the young plants that emerge at the beginning of the rainy season.

If the fadama farmers do not employ DM control measures, the amounts of conidia in the air at the very beginning of the rainy season are still low. When farmers plant early the number of infected plants is low. These infected plants should be rogued and removed from the field. These practices will slow down the development of the epidemic, but will not lead to eradication of the disease, especially if farmers plant new fields next to older fields.

The most important weakness of the DM pathogen is that it has to have young, susceptible, untreated plants to survive. The combination of proper crop management, the use of resistant varieties, and chemical seed dressing is enough to defeat this enemy.

Control Tactics

A combination of the tactics listed below should help to reduce the impact of the disease. The tactics which would lead to total victory, i.e., eradication of the disease, are listed in bold type.

Cultural • Rogue infected plants and take away from the tield-especially in fadama

plantings.

• Farmers in DM zones should plant only once and early in the season, and rogue any infected plants that appear.

• Avoid successive or continuous plantings.

• Farmers who do not have downy mildew-resistant (DMR) seed and cannot afford seed­dressing chemical, should plant some crop other than maize.

Varietal • Always plant DMR seed tbat bas been treated witb seed-dressing chemical

• Never plant a susceptible variety unless treated with a chemical seed dressing which protects against DM.

• Plant DMR seed and rogue infected plants. Chemical

• Use Apron Plus® (brand)" seed dressing for all plantings at a rate of 10 glkg seed.

• Always treat seed if it is of a susceptible variety, if planting late, or if planting in fadamas.

* When treating and planting treated seed, wear gloves or cover hands with polyethylene bag to avoid getting the chemical into the body.

Reference

Adenola, O.A., D.E. Eniayeju, M.O. Omidiji, V.O. Adenle, A.B. Anaso, J.E. Iken, A.O. Ogundipe, E.D. Imolehin, A.Y. Akintunde, and 0.0. Akinola. 1991. Survey of downy mildew disease of maize in Nigeria. Federal Department of Agriculture Publication. pp 1-58.

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Symptoms of the Downy Mildew Disease of Maize Caused by Peronosclerospora sorghi

v. Adenle IITA/lAR&T,lbadan

Introduction

It is essential to be able to recognize the notorious enemy-downy mildew of maize--very well, in order to be able to combat it. We are thus going to observe the symptoms of this disease of maize pictorially, and later on. loqk at the symptoms in the field. One farmer in Osun State in 1992 showed his ignorance of {he disease as he linked the occurrence of downy mildew on his maize crop with the recent Gulf war.

Downy Mildew Strains

Research findings in IITA/lAR&T/lAR have shown that we have two strains of downy mildew in Nigeria. Distinct differences have been observed in the symptoms of the two strains (Anaso 1985). For instance proliferation of ears, elongation of ear shank. and phylloidy of tassels are symptoms of the southern strain in addition to narrow erect leaves. half-leaf symptom, stunted growth, and no cob formation. Other differences between the two strains are:

• Oospores are found in the northern strain. No oospores are found in the southern strain.

• Incidence of DM goes up to 100% in the southern strain; incidence not more than 5% in the northern strain.

The northern strain may exhibit symptom remission (Olanya and Fajemisin 1992). Symptoms are restricted to the 3rd. 4th, and 5th leaves and subsequently there is reduction of symptom expression or complete disappearance of the symptoms as the plant grows. Maize plants infected by the southern strain exhibit symptoms which increase with age (Adeoti and Ogundipe 1990).

Typical Symptoms

Typical symptoms of downy mildew infection on maize often include the following:

• general chlorosis (yellowing) on the leaves of infected plants.

• yellowing on the lower half of leaves of infected plants referred to as half-leaf symptom.

• narrow leaves-leaves of infected plants are often narrower and more erect than those of healthy plants. Infected plants are more slender than healthy ones.

• replacement of the tassels with leafy structures or proliferation known as "crazy tops".

• whitish, powdered growth, resulting from the production of conidiophores and conidia. is often observed on the lower surfaces of the infected leaves, and occasionally on the upper surfaces of leaves.

• in the southern part of Nigeria, infected plants are usually sterile (no cob formation).

References

Anaso, A.B. 1985. Identity, epidemiology and control of downy mildew in maize in guinea savanna. PhD thesis submitted to Crop Protection Department, Ahmadu Bello Univerisly, Zaria.

Adeoti, A.A., and R.M. Ogundipe. 1990. Effect of date of planting on the incidence and severity of maize diseases in Samaru. Paper presented at the 20th Annual Conference of Nigerian Society for Plant Protection (NSPP), held at the International Tobacco Company, Ilorin, 1-14 Apr 1990.

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Olanya, O.M .• and 1.M. Fajemisin. 1992. Remission of symptoms on maize plants infested with downy mildew in Northern Nigeria. Plant Disease 76: 753.

Oyekan. P .• O.M. Olanya. V. Adenle. and G.K. Weber. 1990. Downy mildew of mai:re in Nigeria: Epidemiology. distribution and importance. Paper presented at the workshop on Downy Mildew Disease of Maize at College of Agriculture. Akure. Ondo State.

15

Evaluation and Multiplication of Maize Varieties

J.G. Kling and S.K. Kim liT A. lbadan

The objectives of this training module are: • To enable seed producers to distinguish the important maize varieties.

• To enable seed producers to select varieties adapted to their production environments with characteristics that are well suited to the needs of their clients.

• To provide guidelines for maintaining varieties and producing pure seed.

Types of Varieties The term "variety" refers to a subdivision of a species that is morphologically or physiologically distinct. It is used in a general way to refer to open-pollinated popUlations (Iandraces and improved varieties). inbred lines. and hybrids. "Cultivar" refers to a variety which is widely cultivated and generally implies that it has been improved by selection.

Varietal Characteristics

Maize is adapted to a wide range of environmental conditions and can be used for several purposes. A partiCUlar variety may perform well only in a specific environment. but the genetic diversity among varieties provides a high degree of versatility for the crop as a whole.

Varieties can be distinguished by a number of features: • temperate vs tropical adaptation • photoperiod response • time required to reach maturity (e.g., 90-95 days = early. 100-110 days = intermediate, and

115-120 days = late) • grain texture (e.g .• flint. semi-flint, semi-dent. dent. floury) • grain color (e.g .• white. yellow) • normal vs. quality protein maize • popcorn or sweetcorn • specific resistance to diseases. insects, and parasitic weeds • resistance to abiotic factors such as drought, fertility conditions. acid soils, and temperature

extremes • yield of grain and fodder • specific morphological characteristics

Some of the common morphological features (descriptors) used to identify maize varieties in the field include:

• grain color and texture • plant architecture • leaf angle/orientation • plant and ear height • tassel size. shape, and color • silk color • stem pigmentation.

Maize varieties should be described for these specific, stable morphological features before they are released. For open-pollinated varieties, it may be necessary to describe the extent or range of variation expected for a particular feature. For quantitative traits this can be expressed as the standard deviation from the mean. For qualitative traits percentages may be used.

In spite of this diversity. it is not always easy to identify specific open-pollinated varieties of maize in the field. due to the outcrossing nature of the crop and variations that exist within varieties. Inbred lines and hybrids are more readily distinguished because they are more uniform.

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Types of Open-pollinated Varieties

Population. A group of plants that intermate and share a common genetic background can be called a population. A population can be created artificially by breeding or may be a group of plants that occupy a specific site or geographical area.

Pool. A diverse population which serves as a source of genes for specific characteristics.

Composite. A population fonned by intelUlating a number of different parents, which may be lines, hybrids, or populations. The parents may be chosen because they combine well together or because the breeder wishes to combine particular attributes into a single population.

Synthetic. Most synthetics result from intermating a limited number of inbred lines which are known to have good combining ability with each other. Sometimes noninbred parents are used as well. The progenies are bulked to produce an open-pollinated variety. The advantage of the synthetic is that the farmer can save his seed from one year to the next, while still benefitting from greater heterosis (hybrid vigor) and uniformity in comparison to conventional open-pollinated varieties.

Varietal cross. Two elite varieties are crossed and maintained as an open-pollinated variety. If the parental varieties show heterosis with each other, some heterosis will be maintained in the varietal cross. Farmers can save their seed from one year to the next with relatively little reduction in yield in comparison to conventional hybrids (single, three-way, and double-crosses).

Experimental variety. This term is widely used among maize breeders to refer to a variety that is derived from a limited number of elite genotypes selected from a more diverse parent population. The objective is to create an open-pollinated variety that will be quite unifolUl and well adapted to a defined ecology.

Nomenclature. International maize breeding programs, Centro Internacional de Mejoramiento de maiz y Trigo (CIMMYT), and I1TA use some common conventions for naming experimental varieties (EVs). Examples are: • Samaru 8622-SR. An EV selected from CIMMYT Population 22 based on perfolUlance of

progeny in Samaru in 1986. The SR indicates that the variety is resistant to maize streak virus (MSV).

• Across 86 TZESR-W. An EV selected from an early, streak-resistant, white population from UTA (fZ = tropical Zeal, based on perfolUlance across sites in 1986.

• Across 9028-DMRSR. DMR indicates resistance to downy mildew. • Kamboinse 88 Pool 16-DT. DT indicates drought tolerance.

Types of hybrids

Single-cross. A x B. A cross between two inbred lines results in a single-cross hybrid. Single-cross hybrids potentially show greater heterosis and uniformity than any other type of hybrid. Seed production may be limited, however, because the female parent is an inbred line. Under very adverse conditions, single-crosses may be less stable than other types of hybrids. Single-crosses can be produced in a single generation, whereas three-way and double-crosses require two generaiions for production.

Three-way cross. (A x B) x C. A cross between a single-cross hybrid (female) and an inbred line (male) is called a three-way cross. Seed production potential is improved compared to the single-cross because the female parent is a hybrid. Some uniformity is lost.

Double-cross. (A x B) x (C x D). Double-cross hybrids are produced by crossing two single-cross hybrids. Seed production potential is high. There is slightly more genetic variation in a double-cross field than in a three-way cross production field, resulting in less uniformity. It has been demonstrated, however, that in areas where environmental factors cause great stress to the maize crop, double-cross hybrids may have greater stability and perform bener than single-cross hybrids.

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Modified singJe-cross. (A 1 x A2) x B. An initial cross is made between two closely­related inbred lines, Aland A2. The resulting single-cross is used as a female parent and crossed with another unrelated inbred. The purpose is to improve the seed producing ability of the female parent (usually 20-30%), while maintaining as much uniformity and heterosis as possible in the final product

Synthetic. (A x B x C x .. N). See section on open-pollinated varieties. (P. 17). Topcross hybrid. A cross between an open-pollinated variety (female) and an inbred

line (male) is called a topcross hybrid. Seed production is not limited, but detasseling may be required over an extended period of time due to the variability in the female parent.

Nomenclature. An example of notation for a hybrid developed at IITA is 8321-18. The 83 refers to the year of selection, but the remaining digits are the breeder's code for identifying the specific crosses and selections made (trial 21, entry 18). These hybrids are in the public domain and may be renamed by private companies who wish to market them. 9021-18 STR is a newer version of the same hybrid which was selected in 1990 and has some degree of resistance to Striga hemwnthica.

Choice of Varieties

The success of any seed production agency depends on the quality of products it has to offer. The varieties it chooses to market must be highly productive and well suited to the needs and preferences of maize farmers and consumers in the region.

Sources of Varieties

Some commercial companies maintain their own breeding programs and produce their own proprietary hybrids. Others market varieties that are in the public domain. Public varieties may originate from the international agricultural research centers involved in maize improvement (CIMMYT, UTA) or from national breeding programs.

Experimental variety trials. In West 3Jld Central Africa, lIT A and the West and the Central Africa Maize Network (WECAMAN) prepare and distribute international trials each year. These contain the most promising varieiies currently available from the international centers and regional national programs. In East and Southern Africa, regional trials are coordinated by CIMMYT. In both cases the trials are available free of charge and data can be sent to the appropriate international center or network headquarters for analysis. Trials to be offered by liT A and WECAMAN in 1994 are described in Table 1.

National programs in the region are also encouraged to nominate their own varieties for inclusion in the international trials. Special purpose trials are also available which may be useful as source materials for national research programs or private companies which have their own maize breeding programs. These trials include germplasm with drought tolerance and resistance to Striga hemwnthica, and maize streak virus.

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Table 1. Maize International Trials coordinated by lIT A and WECAMAN, 1994

Trial GraiD Matority Target ecology Color (days)

Hybrid Trials

Wbilegrain W llO Lowland tropics YeHow grain Y 110 Lowland tropics Mid-altitude W,Y 150 Midaltitudes

Open·pollinated Variety Trials

EVT·LSRW W 115-120 Lowland tropics EVT·LSRY Y 115-120 Lowland tropics EVT·ISR W,Y \05-110 Lowland tropics RUVTEarly W,Y 90-100 Lowland tropics RUVT Extra early W,Y 80-85 Lowland tropics EVT·MSR W,Y 150 Midaitillldes EVT·EMSR W,Y 130 Midaltitudes

Notes: W = while, Y = yellow Midaltitude = 800-1500 masI

Ecological Adaptation

For best results, consider only those materials that are likely to be adapted to your ecology. Factors affecting adaptation include length of growing season, rainfall, altitude, photoperiod sensitivity, incidence of specific diseases such as MSV and downy mildew, and the occurrence of Srriga.

Varietal Testing

In order to decide which varieties to produce, trials will need to be conducted in the target ecologies. It would be advisable to have at least one testing site in each of the major ecologies in your region. Varieties which perform well in the northern guinea savanna of West Africa do not necessarily possess the required disease resistance for adaptation in the forest, and forest/savanna transition zones.

Trial management. Trials should be conducted on good, uniform land that is well suited for maize production. For standard open·pollinated variety trials we recommend that varieties are planted in 4·row plots of 5 m length, with a final plant density of 53,000 plants ha·! (21 or 22 plants per row). It is a good idea to overplant and thin back to one plant per hill (for 25 cm spacing) or two plants per hill (for 50 cm spacing). Data can be collected on the two central rows only, leaving the outside two rows as borders. Most hybrid trials are prepared for two-row plots. A minimum of four replications is needed. Appropriate fertilization and good weed control are essential. Trials should be protected from damage by birds and other animals.

Traits to measure. This will depend on the objectives. In general, varieties with high yield, disease and insect resistance, good ear aspect, and good standability (little root and stalk lodging) are looked for. Specific instructions for data collection are included with the international trials distributed by the international centers, and by WECAMAN.

Features of good inbred lines for hybrid seed production. In addition to the quality of the hybrid per se, commercial hybrid seed producers must be concerned with the characteristics of the inbred parents. Use of inbred lines which are difficult to maintain or which produce little seed will reduce the profitability of the hybrid product. Inbreds with good agronomic characteristics such as resistance to diseases, insects and lodging are preferred. Specific features desired of seed and pollen parents are indicated below.

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Seed parent (female) • greater number of seeds per ear • flowering 2-3 days earlier than the pollen parent • good silk emergence • vigorous plants • resistance to ear rots and stem borers • good seed viability.

Pollen parent (male) • high pollen production and viability, extending over a long period • flowering 2-3 days later than the seed parent • slightly taller than the seed parent, so that the tassels are well above the ear position of the

seed parent Post-harvest characteristics. Improved varieties are sometimes not adopted by

farmers in spite of their high yield potential because they lack the desired storage and processing characteristics, or palatability. Measurements which would indicate consumer preferences for particular varieties are not well established. As a general rule, flintier types are preferred for industrial dry milling and for traditional processing which includes removal of the pericarp. The softer grain type is preferred for traditional dry milling of the whole grain, and for traditional wet milling. An important characteristic which is difficult to assess is the recovery rate, i.e., how much final product is actually obtained per kg of maize grain. For green maize consumption, high sugar content and low chaff is desired. Although the total demand for white grain in the region is much greater than for yellow grain, yellow varieties are preferred for human consumption in some places. There is also a demand for yellow varieties for the poultry industry.

On-farm adaptative research. Once a promising variety has been identified it will be necessary to do more extensive on-farm testing and evaluation of consumer acceptance of the variety. In some countries it may be desirdble to run pilot tests to see if the variety is acceptable for industrial processing and utilization.

Introduction of Varieties

Many countries have well-defined systems for evaluating new varieties, varietal release, production of certified seed, and seed distribution. Additionally, each country has its own regUlations regarding seed import and export. Seed producers have the responsibility to become familiar with these regulations and to conform to the standards indicated for seed shipment and distribution of varieties.

Comparative Advantages of Hybrids and Open-pollinated Varieties

Clearly, a private company has more to gain by marketing hybrids than open-pollinated varieties (OPVs). However, representatives of the company must be aware of the pros and cons of hybrid production from the farmers' viewpoint Increasingly in Nigeria. private companies will be called upon to produce cel1ified seed of OPVs under contract so that farmers will have the option to purchase goo<! quality OPV or hybrid seed.

Advantages of hybrids. Potentially, hybrid varieties show increased vigor, disease resistance, uniformity, and yield over conventional OPVs. This does not mean, however, that any hybrid on the market will out yield a good open-pollinated variety under all circum­stances. The performance of any variety depends on its genetic makeup, the quality of the seed stock, and the environment in which it is grown. In West and Central Africa, improvement of open-pollinated varieties has received relatively more effort from maize breeders than hybrid development. One cannot necessarily use comparisons of present-day hybrid and open-pollinated varieties to evaluate the long-term potential for hybrid production in the region.

On-farm trials have indicated a fairly consistent advantage for present-day hybrids in the savanna wne of West and Central Africa. The yield advantage in the forest wne has not been as consistent. Uniformity is a very desirable characteristic for moderate to large-scale farmers who wish to harvest their crop at one time. Uniformity in seed size is desired for greater efficiency in mechanized processing of maize. A small-scale farmer who is harvesting a crop of green maize for his own consumption may not object or may even prefer to have some variability in the variety he grows.

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Advantages of open-pollinated varieties. From the fanner's perspective, one of the major disadvantages of most types of hybrid is that new seed must be purchased every year. As much as a 15-20% reduction in yield can be e){pected if a single-cross hybrid crop is used as a seed source for another planting. Seed produced from open-pollinated varieties can be saved for subsequent planting and passed from fanner to fanner. Production of OPVs is probably more appropriate than hybrid seed prodl,lction in countries that lack a well­developed seed industry and seed disttibution sysfem.

Although under good management the fannj:r may readily regain his initial investment in hybrid seed through increased yields, the cost presents a greater financial risk in the event of a crop failure. There may be little advantage in using hybrid seed under poor management conditions.

In general, more resources (water, light, nutrients) are required for higher yields. Hybrids are no exception to this principal. More fertilizer may be required to achieve the maximum yield potential of a hybrid variety than for an open-pollinated variety with lower potential yield. This does not imply that hybrids IJTe inherently less efficient in uptake and utilization of water and nuttients. In fact, recent studies at lIT A indicate that hybrids may be more efficient than OPVs at intermediate levels of nitrogen fertility. Some fanners also believe that hybrids are more sensitive to stress conditions. Most studies have shown that improved varieties (including hybrids) which perform better under favorable growing conditions will also perform as well or better than local varieties under stress conditions. Some exceptions to this have been reponed. Furthermore, a fanner may prefer a local variety for reasons other than yield potential. In West Africa some local varieties have been shown to have better storability and processing characteristics than most improved varieties. Hybrids can be developed to meet these same criteria, provided the breeder has the appropriate objectives clearly in mind.

Seed PrOduction

Due to the cross-pollinating nature of the maize crop, it is difficult to maintain varietal purity in comparison to such self-pollinating crops as cowpea and rice. Furthermore, offtypes may be less conspicuous in an open-pollinated variety of maize than in genetically uniform crops which makes it particularly important to minimize opportunities for contamination. In self­pollinated crops, an off type may be removed at any stage in the crop cycle without affecting the genetic make-up of the variety. In maize, the genes from a volunteer or offtype plant will rapidly be mixed into the variety unless the plant can be identified and removed prior to pollen-shed.

Producers of maize seed must take extra care to: • use good sources of seed for planting • use sites that are free of volunteers • maintain adequate isolation • rogue the fields at the appropriate times • avoid mechanical mixtures. Good management practices are essential to ensure production of good quality seed, and to enable the seed producer to distinguish and remove off types.

Maintenance of Open-pollinated Varieties

Isolation. The most efficient way to maintain an open-pollinated variety is by growing the variety in isolation. Isolation may be attained: • in time • by distance

For isolation in time, varieties of the same maturity group should be planted at least 3 weeks apart. Late plants should be detasseled after fertilization to avoid contamination of adjacent plots. Early-maturing varieties should be planted first. If an early-maturing variety is planted after a late-maturing variety, it will be necessary to substantially increase the length of time between plantings.

For isolation by distance, a separation of at least 300 m for breeder seed and foundation seed, and 200 m for cenified seed is required. A combination of isolation in time and by distance will provide the best control against contamination. Border rows should be discarded at harvest, since they are more likely to have received pollen from outside sources than those

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in the center of the isolation field. Seed that will serve as foundation seed may be obtained from the center of the isolation field.

Controlled pollination. If adequate isolation is not available, small quantities of pure seed can be obtained by bulk-pollination or plant-to-plant crossing in the nursery. Contamination can be minimized by alternating varieties of different maturity groups or seed color in the field. It is advisable to discard any ears of white varieties that show yellow kernels; the silks must have been exposed and may have been outcrossed with white pollen sources which cannot be detected.

So far we have discussed seed increase methods which involve bulk planting an open­pollinated variety. More intensive selection and control of offtypes may be desired for maintenance of breeder seed. CIMMYT recommends two systems for the production and maintenance of breeder seed: • Stratified mass selection • Half-sib isolation Both require a uniform isolation block.

Stratified mass selection. Approximately 8000 plants are planted in isolation. The field is divided into grids of 16 plants each. Selection is conducted at various stages. About half the plants are discarded by detasseling prior to pollen-shed. Two to three plants that best represent the desired plant type are tagged sometime before harvest. At harvest, the ears from those selected plants are compared and the one that has the most desirable color and kernel texture is selected from each grid. About 500 ears are selected from the whole field and are bulked to form the breeder seed.

Half-sib isolation. About 500 ears are used as females and are planted ear-to-row. A balanced bulk of the variety is generated by bulking equal numbers of kernels from each ear, and this is used to plant the male rows. Male rows alternate with pairs of female rows (2 female rows: 1 male row). Up to 30% of the male plants may be removed prior to pollen-shed. Female rows are detasseled. About 1/2 of the female rows are selected, and the 2-3 best ears from the best plants in each row are used to regenerate the breeder seed. These systems can be modified according to the breeder's objectives.

Population size. Whether one is maintaining breeder seed or just growing a variety for seed increase, it is important to plant increases of adequate size to maintain the variation characteristic of the variety. If the population size becomes too small, there is a risk of inbreeding and inadvertent change in the attributes of the variety. Some of the genes present in the variety may be left out of the seed sample that is used for increase, or the sample of genes obtained may not be representative of the variety. The rate of inbreeding in anyone generation is l/(2N), where N is the number of individuals represented in the seed which is harvested. Inbreeding will accumulate over generations, so if the seed is to be used as a future source for increase, inbreeding should be negligible (e.g. N = 300--500 ears).

It is critical for breeders of open-pollinated varieties to reserve adequate carry-over stock in the event of a crop failure in the seed production field, or other accidental loss of the crop. Ideally, about 10 kg of a variety in current usage should be reserved for possible seed increase. This would be adequate for planting 2 breeder seed increases, should the need arise.

Plant density. It is advisable to increase seed at a lower plant density than is commonly used in field experiments or commercial production fields. The idea is to maintain uniformity and permit vigorous, healthy growth, and maximum yield of selected plants. Planting about 20 kg of seed per hectare and thinning back to about 40,000 plants per hectare is recommended. However, it may be necessary to plant at a higher density if land is limited, or to reduce the extent of thinning (e.g., plant 2-1-2 rather than 2 seeds per hill) or eliminate thinning entirely if seed supply is limited. It is more important to use a low plant density when planting breeder seed for foundation seed production than when producing certified seed.

Maintenance of Inbred Lines

Isolation. Because it is so essential to avoid outcrossing of inbred parents, isolation of at least 400 m or 3 weeks is recommended. The inbred is planted in a uniform block. There is no detasseling and no separation of male and female rows as there would be for hybrid seed production. Good field management is particularly critical for inbred seed increases because inbred lines are less vigorous and sensitive to environmental stresses.

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Controlled pollination. If adequate isolation is not available, seed can be increased by self-pollination.

There is always a small amount of residual segregation occurring within an inbred line. For this reason, breeders may choose to maintain their inbreds by hand-pollination, planting ear to row, and either selfing (using the pollen and silks from the same plant) or sibbing (making crosses between plants from the same line) within a row. Segregants can be more effectively identified and discarded on a row basis than in bulk planting.

Hand pollination may also be used to essentially eliminate the possibility of contamination in an isolation block. Selfed seed from hand pollination may be used for further inbred increase, while the remaining seed harvested is used for hybrid seed production.

Plant density. Inbred lines can be planted at higher densities than non-inbred genotypes due to their smaller plant type. Spacing of 75 cm between rows and 20 em within rows has been recommended. Inbred seed is fairly expensive to produce, so it may be better not to thin and to plant only one seed per hill.

Hybrid Seed Production

In the production of hybrids, one inbred, single-cross or variety, is generally used as a female parent and another as the male parent The female parent must have the capacity to produce adequate seed of good quality.

Time of planting. Male and female rows must be planted at the right time to permit good cross-pollination. For two lines of the same maturity, it is advisable to plant the female line several days earlier than the male to ensure that pollen shed and silk emergence occur at the same time (good nicking). If the female is 2r-3 days earlier in maturity than the male, the inbreds may be planted at the same time. For three-way crosses, it is important to realize that single-crosses may flower 3-5 days earlier than their inbred parents. Planting of male rows may be staggered over 2-3 days to increase the duration of pollen production.

Plant density. For single-cross production, inbred parents may be planted at a relatively high density (e.g., 75 cm between rows and 20 cm between plants within rows). For other types of hybrids, densities of 53,000 plants ha- l are appropriate (e.g., 75 cm between rows and 25 cm between plants within rows). Thinning is not generally recommended due to the high cost of the parent seed.

There are three possible approaches for propagating hybrid maize seed: 1. controlled pollinations 2. isolation + detasseling 3. isolation + cytoplasmic male sterility (eMS).

Controlled pollinations. If limited seed is required for experimental purposes, e.g., for testing in trials, hybrids may be produced by hand pollination. Even though the silks are protected by shoot covers, it is desirable to detassel the female parents in order to reduce the risk of contamination by accidental self-pollination.

Isolation. Isolation of at least 200 m or 3 weeks is required. Male and female rows are alternated in the field. In general, one wishes to maximize the number of females planted because the male plants serve only as a source of pollen and provide no seed. The ratio of male to female rows and arrangement will depend on: • the type of hybrid • pollen productivity • duration of pollen-shed. Extra male rows are usually planted on the outside of the field to ensure good pollination of outer rows and reduce contamination with foreign pollen. Male plants may be removed when pollen-shed is completed (usually about two weeks after the first plants shed pollen). This will provide more light, nutrients, and water for the female rows, which may increase seed yields.

Single-crosses. For most inbred parents, a ratio of two female rows alternating with one male row is recommended (a 4:2 arrangement can also be used, but pollen distribution is better with 2: I).

Three-way crosses. Alternate 4 female rows with two male rows. With a 2:1 arrangement the single inbred male rows would be shaded by the adjacent single-cross female rows.

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Double-crosses. Ratios of 6:2 or 8:2 can be used, depending on pollen productivity and duration. An arrangement of 4 females to one male is also acceptable.

Top-crosses. Arrangements of 4:2 or 6:2 are recommended, depending on pollen productivity and duration.

Detasseling. Detasseling is the most critical operation in a hybrid seed production field. Female plants must be detasseled before they shed pollen. Detasseling should begin when tassels have emerged from 5% of the female plants, and continued until tassel emergence is completed (usually 10-14 days later). Tassels should be removed at least once a day as they emerge from the whorl. The best time to detassel is early in the morning before pollen is shed.

Remember that failure to detassel completely will result in off types in farmers' hybrid maize fields. Farmers will only be willing to buy hybrid seed if they are sure that it is pure and of high quality.

Cytoplasmic male sterility. Cytoplasmic male sterility is a common trait in naturally cross-pollinated plants. Genes in the cytoplasm determine whether males will produce viable pollen or nOL This type of sterility is passed from mother plant to offspring, since the cytoplasm is inherited from the maternal parent. In many species, dominant restorer genes in the nucleus have been identified which can overcome the effects of the sterile cytoplasm. Crosses are made in isolation without the need to detassel female rows, since the female is male-sterile.

The use of CMS for production of hybrid seed became widespread in the USA in the 196Os. Most of the hybrids produced were derived from the same source of male sterility, the T cytoplasm. In 1970, an epidemic of southern corn leaf blight (Bipolaris maydis ) occurred due to the susceptibility of this particular cytoplasm to Race T of the pathogen. About 15% of the hybrid crop was destroyed. The genetic vulnerability of a hybrid seed industry based on a single source of male sterile cytoplasm was clearly demonstrated. Many seed producers returned to detasseling as a mechanism for hybrid seed production. Several additional sources of male sterile cytoplasm were also utilized to reduce the genetic vulnerability of the crop.

Rescue operations at nowering. Although planting of male and female rows may have been carried out according to plan, at times there will be problems in obtaining good cross­pollination. Possible causes include: • Unknown or inappropriate recommendations for planting time for the environment (e.g.,

due to photoperiod response). The result is poor nicking (synchronization of pollen-shed and silk emergence).

• Delayed silk emergence by drought or nutrient stress. • Insufficient pollen production. • Poor plant stands. The following operations may be beneficial in an emergency:

• Cut off the tip of the ear to accelerate silk emergence by 1-2 days. • Collect pollen from male plants and pollinate females by hand. • If there is no wind, shake male lines to enhance pollen dispersal.

Field inspection and removal of offtypes

Seed production fields must be visited regularly to ensure proper isolation and removal of offtypes. Most seed certification schemes recommend about five inspections. Some general guidelines are presented below, but seed producers should become familiar with the official certification procedures in their country. Requirements will differ for breeder seed, foundation seed, and certified seed. Standards will be stricter for hybrid seed than for open­pollinated varieties.

Before nowering. Confirm that isolation requirements are met and that the variety planted has the expected characteristics. Remove offtype and diseased plants.

Flowering. Check the characteristics of each variety in the field. Observe plant type, leaf size and angle, tassels and silks, and any other morphological features that are characteristic of the variety. Remove plants which are much earlier or later than the norm. Remove offtype and diseased plants. In a hybrid production field, check that the female plants have been properly detasseled.

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Arter Dowering. Check that the disease reaction of the variety is as expected. Remove offtype and diseased plants. Verify that male plants have been removed in a hybrid production field.

At harvest. Remove offtype and diseased plants. Select ears carefully before shelling because it is impossible to pick out individual offtype kernels after shelling. Use the following criteria for ear selection: • discard ears with kernels of off type color, texture, and size • discard ears or portion of ears affected by diseases or insects • discard very light ears, which may be due to stalk rot or lodging • in heterogeneous populations, take a representative sample of ears of all sizes; selection for

large ears may lead to higher ear position and increased lodging.

Bibliography

CIMMYT (Centro Internacional de Mejoramiento de Maiz y Trigo). 1984. Development, maintenance, and seed multiplication of open-pollinated varieties. CIMMYT, Mexico D.F., Mexico. 11 pp.

Kim, S.K., and G.K. Weber. 1995. Hybrid maize: seed production and foundation seed multiplication. lIT A Research Guide. lIT A, Ibadan, Nigeria.

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Current System of Commercial Seed Production

A.Joshua Pioneer Hi-Bred Seed Nig. Ltd, Zaria

Importance of Seeds and Effective Delivery Systems

Adequate quantities of improved seeds, fenilizers, and crop protection chemicals are essential if farmers are to produce enough food for a nation at affordable prices. In areas in which maize production is threatened with downy mildew infestation, aggressive, generous use of downy-mildew resistant varieties and hybrids, proper seed treatment, and cultural disease control measures are needed for sustainable food production, and for national food security. A sustainable system for timely supply of agricultural inputs is needed for extension officers to transfer improved agricultural technology to farmers.

An effective extension system has been ~stablished and is showing positive results in many areas through the ADP network. The ADP commercial units and state government owned FASCOMs have played imponant pivotal roles in supplying inputs to farmers. Nevenheless, the extension services still suffer from low funding of operational costs and little funding for seed projects. They tend to be very antagonistic to hybrid seed promotion and misinformed about the benefit of using hybrid maize seeds, etc.

In general, we face the problem of inadequate and untimely counterpart funding; insufficient and untimely funding for successful implementation of special agricultural projects; and funding is not commensurate with the expansion required and post-World Bank suppon sustainability.

Farm Input Distribution Constraints

1. Inadequate and untimely supply offertilizers and agro-chemicals. 2. Social, economic, political, and human problems resulting in unavailable or too costly fuel,

spare parts, and related mechanical inputs. 3. Inadequate awareness of the economic benefits of available improved planting materials. 4. Lack of easy access to credit and marketing of crop produce. 5. Inadequate funding for extension activities and research.

The Way Ahead

1. Put more effon into accumulating and disseminating information to farmers. 2. Encourage private sector participation. 3. Promote activities of state seed coordinating committees to support and coordinate issues

on seed, and seed-related matters. 4. Facilitate seed promotion activities to help farmers and to prevent funher collapse of

valuable private seed enterprises in Nigeria.

Use of Genetic Resistance/Chemical Treatment of Seeds to Combat Downy Mildew

The implementation of an effective quality seed supply system is a critical requirement for effective attainment of national food self-sufficiency and a sustainable downy mildew eradication action program.

UTA supponed by NARS has provided very significant and very useful solutions to the problems of maize DM in Nigeria. A number of genetically tolerant and resistant cultivars, and effective chemical-seed treatment have been made available as solutions for tackling the DMproblem.

Downy mildew did pose big problems 10 Pioneer breeders in some Asian countries, notably Thailand, and is now a problem 10 farmers in Nigeria. Scientists worked hard and evolved several downy mildew-resistant/tolerant hybrids for Asia. Allihese breeding materials are being evalualed for suitability in Nigeria.

Our new white hybrid, Pioneer-3236 (YOG64), has good tolerance to downy mildew. The yellow hybrid. Oba Super 2. is tolerant to downy mildew and good quantities of the seed are available. All our hybrid seeds marketed in the south are treated with Apron Plus®.

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Benefits of Pioneer Hybrid Seed

Hundreds of farmers in the south who planted Pioneer seeds during the 1994 season were very happy and had bumper harvests because their fields were resistant to downy mildew, and the crop growth was excellent. The fields not planted with improved seeds suffered great loss. Table 1 shows a list of available hybrid seed.

Table I. Salient Features of Pioneer Improved Maize Seeds (Hybrids)

Hybrid ObaSuper 1 Oba Super 2 Pioneer New Kaduna character (8321-18) (8644-24) 3236 (8505-2)

Grain White Yellow White White color

Grain Semi-Flint Flint Semi-Flint Semi-Flint texture

Plant 225 215 205 215 height (cm)

Days to 115 115 110 115 maturity

Adaptation Savanna! Savanna! Savanna! Savanna! Forest Forest Forest Forest

Reaction to:

Downy mildew Susceptible Tolerant Tolerant Susceptible

Streak virus Tolerant Tolerant Tolerant Tolerant

Rust & blight Tolerant Tolerant Tolerant Tolerant

Resistance to Moderate Tolerant Moderate Tolerant lodging Tolerant Resistant

Average yield 3.5-4.0 3.5-4.0 4.0-4.5 3.0-4.0 (t/ha)

Yield potential 6.0-7.0 6.0-7.0 7.0--8.0 5.5-6.5 (t/ha)

Hybrids have been proved to give at least 25-30% more yield than open-pollinated varieties and the benefits from the use of hybrid seeds are many times more than the cost paid for the hybrid seed every year. We are convinced of the need to push hybrids for the mutual benefit of farmers and the company. However, seed companies will be most glad to produce high quality open-pollinated seed for bulk supply to public agencies against firm indent and commitment in advance.

Open-pollinated Varieties (OPVs)

The seed sector of UAC has OPV of maize seed with downy mildew resistance. The introduction of improved downy-mildew and streak-resistant, open-pollinated varieties is one of the first steps in developing a seed culture and in exploiting the fruits of the genetic phenomenon "heterosis"; but in open-pollinated varieties, the heterosis is only partially harnessed.

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Seed Availability

Our seeds are available at Pioneer, Lagos, Zaria, Enugu, and Minna depots, at all the NBC (Coca-Cola) depots, NACB-CFC branches, many ADPs and FASCOMs, Leventis Stores, and with several hundred accredited Pioneer distributors nationwide. To cater to the needs of different farm sizes, we have packed our maize seed in 2, 5, and 20 kg bags. UAC seeds depots are indicated in the brochures.

Seed Price

There is a common belief that seed companies are making a lot of money, and large profits. This is wrong. A rate of return of 10-15% would be most satisfying to any investor in seed; but in Nigeria, we are finding this it difficult to meet this target.

The cost of producing improved seed includes: payment for raw seed, parent seed, seed transportation, seed processing, cleaning, grading, sizing, storage, and distribution, cost of seed-dressing chemicals, packaging, rejected seeds, market information and customer services, and some margin of profit (10-12%). Nevertheless, the benefits derived from the use of improved seeds are many times greater than the price paid for the seeds.

Incentives and Conditions Needed for Private Seed Industry

The private seed industry in Nigeria is at an early stage of development and private seed companies need incentives to survive. These include: • Specific government policy to enhance privatization of the seed industry in Nigeria.

• Availability of ADP and FASCOM agro-service centers as sales' outlets for seed, fertilizer and other inputs distributed by private enterprises.

• Increased fanner demand to reduce capacity underutilization resulting from inability to sell the amounts of improved seeds being produced.

• A congenial seed-business environment. The private sector can produce and market large quantities of high-quality seeds of OPVs and hybrids at competitive prices.

• Government agencies to indent and buy available downy mildew-resistant cultivars of OPVs and hybrids from existing reliable seed companies.

• Easy access for farmers to vital complementary inputs such as fertilizer, agrochemicals, and seeds.

• Quality controVseed certification programs to ensure that only high-quality seeds get to the farmers.

• Protection of Nigerian farmers from dubious, spurious seed dealers selling fake OP and hybrid seeds.

• Protection of rights for proprietary lines of improved cu\(ivars developed by private seed enterprises.

• Easy access of private seed companies to breeder seeds of new public sector lines.

• The need for extension workers to actively and fairly promote the use of all the different types of improved cultivars beneficial to farmers (OP & hybrid seeds).

• Whatever the private seed industry can produce, the public sector should not.

• The seed laws must apply equally to all seed marketers regardless of who produced it or how it was produced, and whether or not it was certified or uncertified.

Responsibility of the Private Sector

• Produce and market good quality seeds.

• Provide and complement improved seed campaigns.

• Enlighten the public/provide adverts on economic benefits of improved seeds.

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• Join public sector programs in improved seed campaigns.

• Provide OPVs and hybrids that meet farmers' expectations of quality and type.

• Development of a vibrant private input distribution network involving seed retailers, distributors, farmers, bankers, cooperatives, ADPs/FASCOMs, and private complementary agricultural input dealers.

Fulfilling National Certified Seed Requirement

State agencies should determine their seed requirements each year, and then contract production to reliable seed enterprises, to allow competition. The National Seed Certification Agency (NSCA) must ensure timely certification and quality control, and monitor the quality of seeds in the seed trade. Private seed companies must be ready to provide much more and better quality seed at competitive prices. Certification procedure/standards must apply to all producers of certified seeds.

Seeds Distribution and Marketing

Seed marketing involves three basic activities: accumulation, transportion, and selling. Improved seed must be delivered in adequate quantities at the right time and place to farmers. Seed production agencies must produce and distribute adequate quantities of high-quality seed of beneficial cultivars. The extension services must create awareness of improved seed among cultivators through demonstrations, meetings, and other communication media. The public and private sectors must be partners in progress. Storage of seed must be available and adequate whether provided by the public or private sector, or both.

Seed must be marketed and distributed to those who want to plant improved seed. Seed deteriorating in a warehouse or cultivators waiting for improved seeds contribute to program failure. Marketing and distribution are the most ubiquitous and serious bottlenecks in a seed program. Resolution of this is not easy, but it must be achieved. Development of a proper strategy to produce and distribute resistant seed is a critical step in the downy mildew eradication action plan.

Methods of Promotion-The Creation of Demand for Seed

• Seed promotion through the use of the mass media.

• SPAT and OFAR demonstrations to include hybrid seed.

• Timely and stronger support for all improved seed demonstration plots.

• Use of farm service centers for improved seed marketing.

• Recognition of farmers with outstanding performances on use of improved seeds.

• Farmer-service organizations like cooperatives can playa useful role in agric. input marketing.

The type of promotion depends on what the farmers know, understand, believe, are willing to do, and are able to do. Promotion usually involves field demonstration, the use of signposts. samples, printed materials, and public relations.

SeUingSeed

Selling seed requires actively searching for a buyer, convincing the potential buyer of the value of the seed, and exchanging the seed for his money or other goods or services. Selling seed is not the same as having seed for sale. The essential steps for selling seed include: • attraction for the buyer

• availability of seed to be sold

• making direct contact with the buyer

• knowledge of the product's performance characteristics

• value ratio of seed cost to benefit for the buyer

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Dealer Development and Marketing Channels

Private seed producers need to market seed through dealers as one of the outlet options. Dealers must be found and trained. Primary requisites sought in selecting dealers include: • effectiveness in the local community • fiscal responsibility • organization-seed should be ordered in advance of the planting season • dealer sells seed to active sales person and pays the supplier. Other systems through which seed passes from the producer to farmers include farmers' organizations, cooperatives, and ADP farm service centers.

Value versus Price

Value = the buyer's perception of the benefits helshe will gain in exchange for the money or goods required to obtain the seed.

Price = the sellers concept of the value of the seed and services offered.

Sale = when the buyer perceives the value exceeds the price.

D1ustration of Cost-Benefit of Hybrid Maize Seeds

Type Cost Land Herbi- Fertili- Manage- Yield Total of of Prep. cide zarion ment Income Seed Seed Gross

OP 380 850 1000 1000 1300 3.0 4530 Maize t/ha

Hybrid 780 850 1000 1000 1300 4.3 4930 t/ha

Practical trends applicable on all farms-small- and large-scale farms

Income Net (N)

1050

1487

• Use of improved seed is the most vital, cost-effective means for increasing productivity, and increasing yield/ha and farm income.

• Type of seed planted has significant effect on yield. • 50% of productivity gains in agriculture are due to high-yielding seeds. • 50% additional productivity is due to fertilizer, agrochemicals, management, storage, and

marketing. • Recommendations which make farming profitable to farmers, and make food abundantly

available to the populace at affordable prices, will stand the test of rime.

Summary and Conclusion

1. An overview of the current seed and input delivery system in the country was made. 2. The importance of improVed seeds and measures for effective delivery systems were outlined. 3. Reasonable quantities of high-quality, high-yielding maize downy-mildew resistant and tolerant cuitivars are currently available with private seed companies for procurement and use in the downy mildew eradication program. 4. Types of seeds available for downy mildew zones, characteristic features, sources of the seeds, prices, and where to find the seeds were indicated. 5. The economic benefits of the use of suitable OPVs and hybrid maize seeds in downy mildew-zones were outlined, including the economics of seed treatment. 6. Cost components for production and marketing of improved seeds, and the differences between seeds and grains were provided.

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7. Extension workers should carry out on-farm trials to ascertain the best, and fairly promote the use of the best type of improved seeds most beneficial to farmers (OP & hybrids). 8. The private sector is fully prepared to produce and market a large quantity of high quality seed if a congenial seed business environment is created. 9. Highlights of support needed by private seed enterprises were summarized. 10. In areas infected with downy mildew, aggressive promotion of downy mildew-resistant varieties and hybrids, proper seed treatment. and disease eradication measures are needed for sustainable food production, profitable farming, affordable food for the populace, and for national food security.

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Chemical Seed Treatment

E. P.. Ajayi Swiss Nigerian Chemical Company Ltd. Lagos

Introduction

The earliest record of seed treatment dates back to 60 AD when the use of wine and crushed cypress leaves was described for the treatment of seeds. The next record of seed treatment was in 1620 when Bacon referred to the treatment of cereal seeds with dung. ashes and soot. or alcohol. probably with the objective of controlling diseases. In 1637 the use of brine was described for the treatment of bunt At about this time a consignment of grain soaked with sea water was salvaged from a shipwreck and was subsequently sown. The crop produced was said to be free from bunt while neighboring stands from untreated seed were heavily infested. Since that time many different solutions have been used including brine. calcium carbonate. and copper sulphate. The applica~on was normally made on the floor. using shovels to mix the products with seeds. Today. however. there is a wide range of seed­treatment chemicals available and major advances have been made in the equipment used to apply these products. Seed treatment is normally used as a general term to describe all types of treatment including dressing. coating. incrustation. and seed pelleting.

The Importance of Seed Treatment

Seed treatment has become an important procedure in crop production. There are four major reasons for this. as summarized by C. Potter (Seed Treatment by K.A. Jeffs, BCPC Publications. 2nd Edition): 1. The fITSt and most obvious is that microorganisms on planted seed and environment generally. can destroy the seed or seedling. This may result in a plant stand insufficient to give an economic crop or, in some instances, almost total crop failure. Where precision drilling is practised, it is essential to prevent even a small amount of damage if crop reduction is to be prevented. 2. Chemical treatments can be applied indoors and, thus. are independent of weather conditions and do not require the use of machinery on the land in conditions which may have deleterious effects. 3. Smaller amounts of chemicals are used than when it is applied in furrows or broadcast, and. thus. there is the minimum of pollution. 4. Local application of the chemical to the seed before sowing should not greatly affect beneficial organisms in the soil. Seed treatment for the control of insect pests also offers an opportunity to preserve biological control in addition to providing the chemical product in the right place and at the right time. Frequently. when the insect pest population is high, seed treatment becomes the only guarantee to producing a crop. This is often the case with cutworms and leaf hoppers which can destroy a crop overnight if not protected by a systemic insecticide applied to the seed.

Target Areas for Seed Treater

Traditional seed treatments involved the application of fungicides in powder form for the protection of young seedlings from airborne and soilborne diseases in addition to diseases carried on the seeds. However, it is practical to apply several types of insecticide, growth stimulants and even "safeners" which protect the young seedlings from the effect of herbicides.

Most of the new products today are formulated for application as liquids or slurries and, as such, once applied to the seed are not redistributed on the seed as powders are. This means that more accurate application is required which gives better distribution of the chemical on the seeds.

Ciba-Geigy Agro Division offers a wide range of products for seed treatment which may be obtained through the Swiss Nigerian Chemical Company Ltd (SNCCL).

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Sate Operation of Seed Treatment Machine

1. The machine should be fitted with a dust extraction system so that only minimal chemical, as dust or vapor, can escape into the air breathed by the operators. Where the chemicals are mixed and where the treated seed is being bagged, there should be a good air flow.

2. The chemical products should be delivered to the seed treater in suitable containers which permit the use of a "closed system" to prevent contamination of the operators.

3. The machine should have an automatic stop system, such that if the seed or chemical flow is interrupted then the machine automatically stops.

4. The machine should be operated clean so as not to have large quantities of waste when cleaning out between seed types.

5. It should be possible to fully service the machine without creating a safety risk to the operator.

Handling of Treated Seed

1. Care should be taken to limit the amount of movement of seed after treatment as this causes the chemical to falloff and create a potential dust hazard.

2: Treated seed should always be packed in multiple paper bags to allow for burning after emptying.

3. Seed bags should always carry the name and purpose of the chemical and a clear warning that: • the seed has been chemically treated • the seed is unsuitable for livestock or human consumption • unwanted seed should be disposed off by burying or burning in accordance with local

regUlations • hands should always be washed after touching treated seed • the empty bag should not be used for other purposes and should be burned after emptying.

Handling Chemicals Safely

All chemical products for seed treatment must be stored in a secure manner consistent with local safety regulations.

1. Always read the label instructions before starting to treat the seed.

2. Wear adequate protective clothing such as gloves, overallS, and eye shields.

3. Operate the aspiration system to ensure that there is no dust or vapor in the working area.

4. Always disconnect electrical connections before servicing or repairing the machines.

5. Do NOT eat or smoke in the working area.

6. Always wash throughly after work, and before eating or drinking.

7. All chemical containers should be completely emptied and disposed of in an appropriate manner.

An emergency shower and washing facilities must always be installed adjacent to the working area.

Chemical Formulation Seed Treatment

In order to apply a chemical product as seed treatment, the active ingredient (a.i.) needs to be especially formulated to suit the seed type and the method of application. For example, the formulation must be safe to handle and must not contain ingredients which could adversely affect the germination of the seeds.

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Seed Treatment Equipment

Principles of Mechanical Seed Treatment

1. Theobjective is to provide uniform distribution of the chemical product over all the seeds without causing any chemical damage to them. 2. The chemical product should be applied using the minimum volume of liquid possible to prevent raising the moisture content of the seed unnecessarily which can cause a loss in germination vigor. 3. For good coverage to be obtained using low volumes of product, it is essential that the primary distribution of the product is uniform. This is of particular imponance with absorptive seeds, such as sugarbeet where secondary mixing does not really improve distribution of the product. 4. With highly absorptive seeds or those with a rough surface, it is essential that the chemical product i~ finely atomised using an atomiser to distribute the small droplets directly onto the individual seeds.

On-Farm Treatment

1. The machine should be capable of handling different seeds and various formulations with a minimum of adjustment 2. The machine should be compact and easily transportable from farm to farm to allow for treatment of the seed immediately prior to planting.

Selection of Appropriate Seed Treatment Equipment

The selection of the equipment to be used depends on a number of factors including: • seed to be treated • the chemical formulation-liquid, powder, or a combination • treating capacity desired • quality of treatment-normal treatment or coating • dosage rate of chemical to be applied • whether the seeds are dusty or pre-cleaned • whether the seed has already been treated with a chemical product • how long the seeds will be stored prior to planting • storage of the treated seeds.

High Capacity Industrial Treatment

In order to select machines, the seed treatment company must fully analyse all aspects of the proposed treatment including the following aspects:

Equipment • Seed/type & capacity • Versatility • Calibration • Uniform seed coating • Aspiration + filter system • Container + pumping system

Easy to clean and service

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Features tonnes/hour-max./min. seed types formulations easy + accurate one/two products "c]ean" convenient

Seed Certification Regulations in Nigeria

E. Adegbuyi National Seed Service, Ibadan

Seed is an important and basic input to increase crop yield per unit area. Seed must not just be supplied in ample quantities, it must be of high quality. Seed quality denotes the following attributes: • high genetic purity • high viability/vigor • high physical purity • appropriate low moisture content • freedom from disease infection • freedom from mechanical damage • freedom from insect damage • good treatment coverage • good size • good appearance-eye appeal • good performance potential • homogeneity of seed lot • good length of life (storability) Seed certification is a legally sanctioned system of quality control of seed production (FAO 1969, Delouche and Pons 1971). Its main purpose is to maintain and make available to the public, high-quality seeds and propagating materials of superior crop plant varieties, so grown and distributed to ensure genetic identity and genetic purity (FAO 1975). Other important quality attributes that interest a seed certification program include disease, viability, mechanical purity, and weeds.

Certification Objectives

In several countries with well-functioning quality control schemes, seed certification has accomplished three primary objectives (Douglas 1971): 1. The systematic increase of superior varieties. 2. The identification of new varieties and their rapid increase under appropriate and generally

accepted names. 3. The provision of a continuous supply of comparable material by careful maintenance.

Certification Agency Activities

The major activities of a seed certification agency include:

• establishment of minimum certification standards

• registration of varieties for seed certification

• registration of seed growers

• registration of processing plants for certified seed

• registration of seed fields

• field and bin inspection

• seed sampling

• seed testing

• international agreements for seed certification.

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Phases of Certification Certification is carried out broadly in six phases namely:

1. receipt and scrutiny of application

2. verification of seed source

3. field inspection to verify conformity to the prescribed field standards

4. post-harvest supervision of seed crops

5. seed sampling and analysis to verify conformity to prescribed seed standards

6. granting of certificates, and tagging and sealing of the container.

Technically, the activities and the standards checked for during each major activity are:

Activity

Seed field inspection diseases, weeds

Control test (grow out test)

Seed quality tests in the laboratory

Control and Standards

Standards

Varietal purity, isolation, seed-borne

Varietal purity, seed-borne diseases

Varietal purity (to a limited extent), analytical purity, health gennination, moisture content, seed

size etc.

Absolute control over all the operations during seed production is not possible but control is exercised as far as possible in two ways: 1. By ensuring that seed is multiplied and processed in such a way as to minimize the risk of mechanical damage and genetic contamination. 2. By setting standards which are adopted (or imposed). Seed certification agents monitor seed production and seed stocks against such standards at a stage in which the variety can be distinguished.

Standards are generally of three categories: 1. The general standard. The general standard specifies the purpose of certification, the agency responsible and its functions, eligibiliiy requirement for certification of crop/variety, classes and sources of seeds, phases of certification, field inspection and field standards, sampling, methods fOT testing for germination, purity moisture content, seed health, methods for processing and packaging, including seed treatment, tagging, labelling and sealing methods, and the provision for the use of sub-standard seeds.

2. The specific standard. The specific standard specifies the application and amplification of the general standard, and requirement, number of field inspections and stages in conducting a field inspection, isolation distance, tolerances in the number of off types, pollen shedder, other crop plants, weed plants, and plants affected by designated seed-borne disease.

3. The seed standard. The seed standard specifies the minimum pure seed germination, seed moisture and maximum inert matter, weed seeds, other crop seeds, and seed-borne diseases.

In a controlled system of seed multiplication, three classes of seeds are recognized: 1. Breeder seed is normally grown for one or more generations, and produced or controlled by the originating institution or plant breeder; it provides the source for the increase of foundation seed. 2. Foundation seed is produced from breeder seed, such that genetic identity and genetic purity are maintained. Foundation seed is intended for the production of certified seed. This class of seed is subjected to official inspection and must conform to certification standards defmed in the regulations of the country.

36

3. Certified seed is produced from foundation seed and is intended to be used for the production of certified seed for one or more generations, and for food crops. Certified seed is subject to official inspection and mu~t conform to certification standards defined in the regulations of the country.

Field Inspection

Seed fields are controlled by various inspections of the seed crop. The objectives of field inspection are to: • Confirm the details on the application form completed by the seed grower. • Verify the origin and identity of the variety. • Check on cropping history. • Check on cultivation conditions. • Check on isolation. • Detect mixtures with other varieties. • Assess weed contamination. • Detect disease incidence, particularly seed-borne disease. • Ensure that the standards prescribed for the species/variety are met. • Give general advice on the operation of the seed certification scheme. • Seal the certified seed crop when all conditions have been met.

Seed fields are inspected by certification officers who are trained to conduct field inspections by the Certification Authority. Many inspections are necessary in a seed field and usually a seed crop is inspected at the following stages: Vegetative stage: to verify seed source, confirm details on application form, verify the identity of the variety, confirm correct hectare planted, check on isolation (which is, e.g, usually a minimum of 200 meters for a certified class of maize, and 400 meters for foundation seed), check on contaminants and seed borne diseases, and that rogueing based on vegetative character has been carried out satisfactorily. Flowering stage: to confirm that no undesirable pollinating plants are within prescribed isolation distance and to check on rogueing practices. In a hybrid seed field to confirm that detasseling operations are satisfactory. Pre-harvest inspection: to make a final check on rogueing, to confirm that the seed grower has removed all the male lines in a hybrid seed field, and to authorize harvesting.

Inspection walk. During the inspection walk, the inspector takes samples at random within the field free from bias, following recommended travel patterns in order to produce accurate results. Detailed examinations are made on a number of seed plants (e.g in maize in a strip (l x 20m) called a quadrant using distinguishing characteristics between maize varieties) during inspection. During the inspection walk, estimates are made of crop varieties, diseases, condition of crops, off types, and impurities. The number of counts made depends upon the hectares of seed crops.

After recording, calculations are done as per the field standards prescribed in the Seed DecreeIRules and Regulations using tables of reject numbers. After each inspection a written report signed by both the grower and the certification officer is produced. Double counts are taken in seed fields that are liable for rejection. Report forms are completed in quadruplicate and are forwarded to the appropriate persons/offices; one copy to the headquarters of the certification agency, one to the regional seed certification officer, one to the seed grower, and the certification officer keeps a copy for reference purposes.

Processing Plant Inspection

Certification officers must inspect deliveries of seed crops to the processing plant to ensure that the harvested seed crops get to the processing plant and are not diverted elsewhere or contaminated with impurities.

The certification officer has to be present during the sorting out of off type ears and diseased ears in the processing plant. Checks are also made to ensure proper separation of seed lots to prevent admixture, and to assure cleanliness, adequate pest control measures, proper packaging, correct declaration of weight, appropriate chemical treatment, and that safety measures have been effected.

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Seed Sampling Samples are taken from cleaned seed lots for onward delivery to the official seed testing laboratories for analysis. Samples taken must be truly representative of the seed lot The International Seed Testing Association (1ST!>,) prescribes the maximum size of a seed lot; for seed maize it is 40,000 kg. The minimum submitted sample weight to the testing laboratory is lkg and, for moisture content determination, 100 g. 1ST A prescribes the correct sampling equipment which includes drier, probe, and automatic samplers. The sampling intensity for seeds in bags and in bulk are prescribed by ISTA. All samples taken from one part of the seed lot are called primary samples. A composite sample comprises all samples taken from different partS in the seed lot combined together. The submitted sample is the sample sent to the seed testing laboratory. On arrival in the seed testing laboratory, the sample is registered and given an analysis or reference number which is used to identify the sample throughout its life span in the seed testing laboratory. In the laboratory the sample is divided to give working samples.

The detailed information accompanying the seed sample is recorded and kept for reference. Samples for moisture content tests are taken within 24 hours of receipt of the sample in the laboratory to prevent moisture migration to and from the seed.

Seed Testing

Many quality tests are conducted in the seed testing laboratory. Some of the common tests include:

Moisture content determination. The moisture content of a seed 10[ affects the storage life of the seed lot. Seed samples for moisture content can be determined by two methods, direct and indirect. Direct methQds are accurate but time consuming, and include distillation, the use of phosphorus pentoxide, overdrying, vacuum drying, dessication, and the Karl Fisher method. 1ST A prescribes the oven method as standard, which for maize is drying in an air oven at 130°C for one hour. The difference in the weight of seed before and after drying on a percentage basis is the moisture content of the seed lot. Indirect methods are not accurate but they are fast. These include the use of electric moisture methods, dieletric meters, hair lJygrometers, and infra-red. Some of the common meters used are the Steinlite moisture meter, and the Universal moisture meter.

Purity analysis. The objective of this test is to determine the composition by weight of the sa..'lIple tested, and, by inference, the composition of the weed seed in the lot. For maize seed, 900 g of maize seed (about 2,500) are separated into 3 namely:

I . Pure Seed: which refers to the seed of maize that is more than half of the original size of the species under test.

2. Other Crop Seeds: which include seeds of other crop species (less than 5%), and weed seeds. Seeds must be more than half original size.

3. Inert Matter: which consists of chaff, stone, sand, pieces of broken seed or damaged seed, one half or less than half the original size, nematode galls, etc. The percentage of the pure seed fraction is the percentage purity. The composition by weight

of each component is calculated to one decimal place. Germination test. The germination test evaluates the planting value of the seed, i.e. the number of seeds that will produce normal seedlings under favorable conditions. 400 seeds from the pure seed fraction either in 4 or 8 replicates are planted in moistened sand, paper towel or kimpack, and kept in a germinator (cabinet or walk in type) under prescribed conditions of relative humidity, temperature, and light for a specified period of time (7 days for maize) after which the test is evaluated; the first count on the 4th day, and the second count on the 7th. Seed/seedlings are classified as:

1. normal seedlings that possess all the essential structures and are capable of developing into a normal plant under favorable field conditions. 2. abnormal seedlings (those which lack the essential structures). 3. hard seeds

38

4. fresh ungenninated seeds 5. dead seeds The total number of normal seedlings in the four replicates is added and divided by four. The

germination percentage and the purity analysIs are usually the two tests required for labelling purposes. Seed lots that meet the prescribed national standard are issued with seed certification tags which are affixed to seed bags containing the certified seeds under close supervision of an official of the certification agency.

Other seed quality tests which the sender may request include: 1,000 seed weight which is evaluated on 8 replicates of 100 seeds randomly picked from the

pure seed fraction. Seed weight has been found to correlate with seedling vigor in some species.

The viability or tetrazolium (TZ) test. This test is based on topographical staining. e.g for maize seeds. seed is soaked in water for hours after which the seed is bisected longitudinally and then soaked in a 1 % solution of 2,3.5, tripenyl tetrazolium chloride or bromide. Viable seeds stain red (formazan) in colour. The test shows the presence of dehydro¥enase (enzymes) that are present in living organisms.

Determination of other species tests is conducted on 1000 g (about 25,000 seeds). A seed research is made for all other crop species (complete test) in the sample or specified crop species (limits test) in the sample. Foreign seed content calculated on the weight of each of the components is recorded in weight. The latin names of the other crop species are written.

Seed health testing may be conducted on plant parts or seed to ascertain the presence of diseases. particularly the seed·borne diseases. Seed health testing is an important requirement in transportation of seed across international borders (phytosanitory certificates).

Varietal purity testing. Varietal purity determination is done to a limited extent in the laboratory. Variety purity testing is done more during field inspection and in control tests.

Tolerance tables. These have been provided by 1ST A to ensure seed quality. Tests conducted are accepted only when within tolerance.

Sealing the Seed Lot

Results of laboratory analysis will reveal the quality of the seed lot. In a compulsory certification scheme. if the seed lot meets the prescribed national seed certification standards, tags are issued to be fixed to containers carrying the approved seed lot, and the seed lot is sealed.

In a voluntary certification scheme, such analysis is required for truthfully declaring the seed quality on the labels. catalog or invoice attached to the seed lot.

Control Tests

A rigid system of control and maintenance of varietal purity may be created by combining field inspections and control tests (grow out tests). In a control test plot a sample of a seed lot intended for production of certified seed is planted in 2-3 replications arranged and designed for good examination of the rows. The rows are planted side by side with plots planted with authentic samples. The plants are examined closely during the growing season and detailed examination and counts are made on other varieties, offtypes. and diseased plants. Inferior seed lots are eliminated from further mUltiplication before processing.

In a pre-control test, the plots are established before or in the same growing season as the seed crop (on the field). In a post·control test, a sample is planted and examined in the plot during the next growing season. The control plot serves as a check on the accuracy and efficiency of the work done in the previous season and is used as a self'evaluating process for the certification agency.

39

Certification Schemes A certification scheme can be voluntary or compulsory. Compulsory Certification of Seeds. In this system, all seed crops and seed lots must be subjected to official inspection by the certification authority. A minimum standard is a feature of compulsory certification. Advantages of this system are: • All the seed in the market is certified and the standard can be maintained. • The quality of seed is guaranteed. • It is suited to peasant agriCUlture, particularly in countries where the majority of farmers are

illiterate. Disadvantages of this system are:

• The input by the certification authority is costly and time consuming. • Because of the amount of seed needed, some seed lots may be produced by less competent

growers.

Voluntary Certification of Seeds. In this system the seed producer mayor may not subject his seed crop and seed lotto official inspection by the certification authority. The advantages of this system is that the best farmers usually produce seed and the quality is high. The disadvantages of this system are that: • It does not eliminate poor quality seed from the market • It can be confusing to farmers to have both certified and uncertified seed in the seed trade.

Informing the Farmer

There are two basic ways to inform the farmer/buyer of the seed about the quality of the seed he or she is buying; minimum standard, and truth-in-labelling.

1. Minimum Standard

In this system, the seed in the container must meet the minimum levels of prescribed seed field and seed lot standards. Usually each bag will carry a tagllabel which itself is a guarantee of the quality of the seed. The advantage in this system is that the system is easy to check and enforce, and easy for farmers to understand. The minimum standard is a feature of compulsory certification. It is suited to peasant agriculture where many of the farmers are illiterate. The disadvantage is that the farmer is given no choice i.e. it is not a flexible system, all farmers must buy seed above a minimum standard.

2. Truth in-labelling

In this system, seed of all types of quality are sold in the seed trade. The quality of the seed lot is stated on the label, attached to the container, or on an invoice, or in a catalog. It is up to the purchasers to ensure they get the right quality of seed by using the information available to them.

The advantages are that farmers have a wide choice of quality of seed, and the system is flexible. It is expected that high quality seed will drive low quality seed out of the market. The disadvantages are that farmers find it difficult to understand the system since they have to be aware of the relative importance of quality and cost, and the system is difficult to check and enforce.

Current Status of Seed Certification in Nigeria

The Seed Certification Agency in Nigeria operates within the National Seed Service. It is independent of seed production and marketing concerns. A program leader supervises the operations of the program assisted by a national coordinator.

A regional seed certification manager is located in Ibadan, Ilorin, los, Samaru, and Umudike. Twenty state certification officers and field inspectors are located in each state of the federation. Four seed testing officers and seed analysts are in four official seed testing laboratories (Ibadan, Jos, Samaru, Umudike), and control plot officers constitute the technical base of the seed certification program.

Certification officers and field inspectors are mobile. Both field and laboratory staff have been well trained locally or abroad in their respective areas of specialization. The Ibadan, Umudike, and Samaru laboratories are equipped to carry out statutory tests for labelling controls. Grow out tests are conducted in Ibadan and Samaroo It is important that

40

each seed production enterprise has its own internal quality program which will work in close collaboration with the official seed certification staff.

Seed Legislation

A Seed Decree was promulgated on 23 November 1992 as the National Agricultural Seeds Decree No. 72. The decree provides for certification of seed.

References

Copeland, L.E. 1976. Principles of seed science and technology. Burgress Publishing Company, Minneapolis, Minnesota, USA.

Delouche, J.e., and H.S. Potts. 1971. Seed program developments. Mississippi State University, Seed Technology Laboratory (Mimeographed).

Douglas, J .E. 1971. Seed certification manual. National Seeds Corporation and Rockefeller Foundation. New Delhi, India.

FAO (Food and Agriculture Organization of the United Nations). 1969. Control of production and distribution of seed. Rome M1I95987.

FAO (Food and Agriculture Organization of the United Nations). 1975. Cereal seed technology. A Manual of cereal seed production quality control, and distribution, edited by W. P. Feistritzer. FAO, Rome.

FAO (Food and Agriculture Organization of the United Nations). 1982. Technical guideline for maize seed technology. FAO, Rome.

FAO (Food and Agriculture Organization of the United Nations). 1983. Technical guideline for cereal seed testing. FAO, Rome.

Thompson, J.R. 1979. An introduction to seed technology. Leonard Hill, UK.

Wellving, A.H. A. 1984. Seed production handbook of Zambia. Department of Agriculture, Lusaka, Zambia.

41

Logisitics of On-Farm Testing for Downy Mildew Control

O.A. Adenola and S.A. Adedeji

Introduction

Assistant Director/Coordinator and Extension Agronomist, National Rice/Maize Center, Ibadan

Maize is the most commonly grown cereal in Nigeria today, with an average production of 3 million tonnes annually. It is one of the staple foods in Nigeria and is also used for feed, and in pharmaceuticals. It is cultivated throughout the countty on an estimated 2 million hectares of land, of which 80-85% of the area falls in the savanna. Some of the constraints of maize production are biotic, and include downy mildew disease caused by the fungal pathogen Peronosc/erospora sorghi.

Downy mildew disease was first found in Nigeria in 1970, and was reported to be endemic in six states of the federation, namely: Edo, Kogi, K wara, Ondo, Osun, and Oyo. The disease is spreading, and may soon reach Benue, Bomo, Niger, and Ogun states.

Spore production occurs on plants displaying various symptoms such as leaves with white and yellow streaks from the base to the tip, chlorosis, and narrow and stiff leaves. Plants are either stunted or too tall , and usually produce no yield at all. The importance of downy mildew can be seen in the huge financial loss to the nation. In 1991, it was reported to have caused a loss of N341 million. Available control measures for downy mildew include: • the use of resistant plant varieties • the use of chemicals for seed treatment (Apron Plus®) • timely planting and good farm sanitation. It is therefore, the role of extension programs to create farmer awareness of the disease and to train farmers on the various methods to control the disease. This paper will therefore discuss the logistics of on-farm testing for downy mildew control.

Objectives

The major objective of this session is to impart knowledge through demonstration. At the end of the workshop, participants will be able to: • create awareness of downy mildew disease • train extension agents on how to set up downy mildew control trials • demonstrate the importance of resistant varieties in downy mildew control • demonstrate the importance of chemical treatment in downy mildew control • use resistant varieties and/or chemicals to control downy mildew • assist farmers in recognizing and controlling the spread of downy mildew disease.

Recommendations for On-Farm Testing

In order to reduce the variability which arises from one location to another to the barest minimum, the same set of recommendations must be followed by all collaborators. The following set of recommendations are therefore provided to guide each collaborator.

Site selection. Select sites that are accessible and located on farmers' farms. A list of locations should be forwarded to the coordinator as soon as the trials are planted.

Land preparation • Prepare land after the first good rain • Plough and harrow the land thoroughly

Fertilizer application • Apply 200 kg 15-15-15l\PK (4 bags) before planting • Broadcast before harrowing • Side dressing-4 weeks after planting (knee height, 6-7 leaves stage) • Band application 10 cm a way from the plants

Planting • Late planting is encouraged for this trial to ensure that disease incidence will be high. • Plant late May/early June to have maximum infection levels. • Plant 75cm x 25cm with one seedlhole • 75cm x SOcm with two seeds!hole

Weed control. Good weed control is essential for good maize yield. • Apply pre-emergence herbicide within 2 days of planting. • Hand weed when necessary (2 base weedings).

Seed. Use healthy and viable seeds with good yield potential. About 10 g of seed is needed for each plot. Plot size and layout. The trials will be simple, non-replicated, and will be located in 10m x 10m plots which are planted along a well-travelled road.

Treatments

1. Untreated OPV (Susceptible) } 1ZB-SR-SG

2. Treated OPV (Susceptible) ffi-92C-1221

3. Untreated OPV (Resistant) } DMR-L-SR

4. Treated OPV (Resistant)

5. Untreated Hybrid (Resistant) , } OBA Super 2 (Yellow)

6. Treated Hybrid (Resistant)

Source of Seed. Seed will be sourced from UTA, NSS, and seed companies. Seed Treatment. Treat seed just before planting, at the rate of 10 g Apron Plus® to 1 kg of maize seeds. Mix the Apron Plus® properly with the seed.

Precautions • Use hand gloves or polythene bags to protect hands. • Use nose protective cover. • Do not smoke while mixing. • Wash your hands throughly after mixing.

Assessment of Effect of Downy Mildew Disease • Half leaf chlorosis • Leaves with white-yellow streaks from base to tip at the base of the leaf • Narrow and stiff leaves • Plants are either stunted or too tall • Presence of crazy tops • No formation of cobs • Naked cob on the tassel.

The amount of field loss depends on the percentage of plants that have systemic infection.

Monitoring • There should be regular monitoring to assess the effect of the disease. • Each site should be visited weekly by YEAs. • Suitable fields for field days will also be selected during the monitoring visits.

Field Days. Two field days will be conducted in each of the affected states. Details of sites selected for field days should reach the Downy Mildew Task Force Chairman 2 weeks before the field day.

43

Harvesting and Data Collection

• The trials will be harvested when dry or they can be harvested 25 days after flowering for eating green.

• Whichever harvest time is selected before harvest, count how many plants have good ears and how many crazy tops there are per plot.

MateriaJs Needed

• Resistant OP • Susceptible OP • Resistant Hybrid • Apron Plus® • Tape (pre-measured sticks in lieu of tape) • Pegs • Rope • Chemical (for weed controlHhoe in lieu of chemical)

Note. All agronomic practices should be optimum for each plot (treatment) and equally treated so that any observed differences will be attributable to the treatment effect.

44

Extension Communication

A.O. Oyedokun National Agricultural Extension and Research Liaison Services, Ibadan

Communication Process

The word communication can mean !l>-lIIly different things including personal interaction, transport, and even satellite technology. Communication can be dermed as the process by which an idea is transferred from one source to one or more receivers with the intent to change their behaviour, e.g., awareness of a new soybean variety (knowledge) or acceptance of alley farming (behaviour). Another definition by Rogers and Kincaid (1981) dermes commupjcation as a transactional process that involves the exchange of ideas between 2 or more individuals in an attempt to arrive at a convergence in meaning. We are concerned in this paper with communication as a process taking place between people, i.e., between extension agents and farmers or between extension workers and subject-maner specialists.

All human beings communicate, however we are not all good communicators. The communication process consists essentially of five structural elements, i.e., sender, message, channel, receiver, and noise.

The Sender

The sender is the initiator of the communication process. It is the individual who has the "need" to get something across to the receiver. In the agricultural set up we may assume that the extension agent who needs to generate interest in the adoption of a new crop variety is the sender. A sender should possess the following characteristics to be effective: 1. Knowledge about the subject matter area. If farmers must develop trust, then the agent must demonstrate expertise in any recommendation advocated for adoption. The agent must be theoretically balanced and technically competent. Inadequacies in these areas could jeopardize the success of not only the currenl program, but of future ones. 2. Understanding of the target communities. Mosl communities have inherent cultural beliefs and norms that may be at variance with those of program originators. Therefore implementation programs cannot be decided in a unilateral way but should be developed with members of the target community.

Apart from the cultural aspect, agents also need to have a grasp of the educational status of the target audience. 3. Communication skill. The agent must be able 10 communicate effectively with the use of well-developed teaching aids.

The Message

The message is any information that the agent desires the client to receive, understand, accept, and act upon. The message must be clear as to its purpose. The message must be economically feasible, socially consistent, and culturally compatible with the farmers immediate community and practices. The message component of the communication process must be based on the needs and interests of the client.

Channel

The channels of communication are the various methods available for a communicator to reach an audience. However, a message can be ttansmined not just through wordlhearing (radio, television, training session, etc.), but through visual aids, e.g., films, pictures, and posters, or through the written word, e.g., newspapers, and extension bulletins. The five senses of sight, sound, smell, touch, and taste can be effectively used in communication either singly or in combination. Direct, face-to-face interaction via the spoken word is preferable because it allows for questions to be raised and answered immediately.

45

Receiver

A receiver in the communication process is the individual whom the message is designed to reach. For our purpose the receiver in extension communication is the farmer. The impact of the message on the receiver results in a numoer of actions-decision, confirmation, implementation etc. which again become messages and feed through various channels back to the original sender. Thus sending out a message is juSt half the exercise, finding out the extent of its spread among the population client is other half. Without feedback, it is difficult to know how successful our efforts have been in trying to communicate.

Noise

Other than noise there are certain barriers which interfere with the communication process causing distortion and misunderstanding resulting in communication breakdown. These include self interest, emotions (feelings), conflicts (individual goals vs group), semantics, faulty reception, and rumor.

Extension Teaching Methods

Generally speaking, communication/extension methods can be broadly classified into: • audience size (Table 1) • form (Table 2) • types of media (Table 3).

Table 1. Classification of methods according to audience size

Individual Contact Group Contact Mass Contact

Farm and home Demonstration Bulletins visits

Office calls Meetings, leader training Leaflets

Telephone calls Meetings, lectures Radio, television

Personal letters Conferences, farm tours Exhibits, posters

Result Field days, youth & Agricultural shows, demonstration farmers clubs, local musicians

cooperdtives

Group extension methods may utilize some other media such as field slides, cassette tape, printed medium speech, or demonstration.

46

Table 2. Classification ofrnethods according to form

Written

Bulletin. leaflets

News articles Personal letters

Spoken

General and special meetings of all kinds

Farm and home visits Office calls, telephone calls, radio

Demonstration meetings television, musicians, dramatic groups, agricultural shows.

Visual or Objective

Result demonstrations exhibits, posters. motion pictures, charts, slides, and other visuals aids.

Adapted from Wilson and Gallup, Extension Teaching Methods: Extension Service Circular No.495,1955.

Table 3. Classification of methods according to types of media

Electronic

Print

Face-ta-Face

Others

Mass

Film, radio, T.V., video cassette tape

Newspaper, books, leaflets, magazine, posters

Speech, rally, theater

Talking drums, exhibition

Inter-personal

Telephone, computers

Letters, telegrams, telex, FAX

Conversation, individual farm visit, group extension methods

Messengers, demonstration

Source: Reproduced from Knowledge Transformation and Utilization, International Agricultural Center. Wageningen, Netherlands.

Factors for Selecting a Method

Choice of an appropriate method is important for effectiveness, cost-savings, and reaching the audience. It is however important to note that: • There is no 'best' method. The particular situation determines which method is most

suitable. • Use of a combination of methods is better than a single method. • Methods overlap. Factors involved in the selection of methods for effective communication can be broadly divided into: • Characteristics of the farmer • The extension agent and the agency • The environment

47

Characteristics of the Farmer The following must be considered in choosing a method of communication with farmers: • capacity of interpretation Oanguage) • literacy levels (schooling) • socioeconomic level (market or subsistence economy) • needs, problems, and interests • stage in the adoption process

The Extension Agent and the Agency • The technical competence of the agency • Availability and knowledge of communication gadgets • The resources of the agency, particularly staff and materials

The Environment • Village location • Infrastructure and facilities, e.g., motorable roads, village hall, and electricity supply • Time/season of the year

Conclusion

Communication is crucial in all extension activities, and as such, a thorough understanding of the communication process is absolutely essential for effectiveness. There is a good variety of extension teaching methods for the extension agent. These however must be carefully selected.

Bibliography

International Agricultural Center, The 1985 Manual. Knowledge Transformation and Utilization. International Agricultural Center, Wageningen, Netherlands.

Swanson, B.E. (ed.) 1984. Agricultural Extension: A reference manual (2nd Edition) F.A.O., Rome.

48

Status of Downy Mildew Resistant Seed Requirement, Production, and Distribution Outlets by State-Seed Working Group

Status of DMR Seed Production by ADP-May 1994

Total area under maize ('000)

Total seed requirement (tono .. )

Total seed reqolremeot (based 00 correat effec .. tive demand) (tonnes)

Quantity of seed Ilvall· ablel9ll4 (toDnes)

Kwara

102ha

2.550

80

33

Oyo Osuo

260ba 5Sba

6,500 1,450

100 50

90 20

Varieties planted

DMRESR-Y DMRESR· Y&W Suwan 1 DMRLSR-W DMR-Y&W DMRLS-Suwan I Suwan I. TZPB- W&Y

W

Sales outlets (Farm Service Center)FSC

Method of production

No. of Growers

FSC= 14 Priv.sd. Co. S.pt =2

ADP=DE& OG5%:95% Priv.Sd.Co. Priv.Sd Grower

14

TZSR-Y

FSC=23 Priv.Scl. Co. S.pI. = 3

ADP=DE& 0020%:80% Priv.sd.Co Priv.ScI. Grower

52

Note: ADP = Agricultural Development Project DE = Direct Effort FSC = Foreign Service Centers 00 = Outgrow ... Priv. Sd. grower = Private Seed Grower Priv. Sd. Co. = Private Seed Company Priv. Sd. Procl. = Private Seed Producer S.pL = Sales Point

FSC=23 Priv.Sd. Co. S.pt = 2

ADP=DE& OG5%:95% Priv.Sd.Co. Priv.Sd. Prod.

10

49

Kogl Oodo

150ba 90ba

3,750 2.250

20 100

50 68

DMRESR Suwen I W&Y DMRLSR-Y

FSC = 16 Priv.sd. Co. S.p!=2

ADP=DE &OG 12.5% : 87.5% No.sd.Co. Priv.Sd. Producer

12

DMRESR W&Y

FSC = 26 sales Ag. 52 F.DisL = 7 Mini Stores = 29 point

ADP=DE&oo 10%:90% Priv.Sd.Co. Priv'sd. Producer

25

Edo

98ba

2.450

15

15

TZSR·Y&W Suwan 1 DMRESR-W

Input Store = 14

ADP=DE &00 Priv. Individual Producer

5

ADP Seed Production Projections for 1996

ODdo Kwara Oyo Osun Kogi Edo Total

Methods QlDnnes ha Qlonnes ha QlDnncs ha QlDnnes ha QIDJUles ha Q IDMes ha tlha produced

1994 50 35 35 33 60 60 42 42 43 50 15 20 No-of growers

25 14 52 10 12 5 1995 50 35 40 45 60 60 52 52 47 53 20 25 No. of growers

25 20 53 10 12 5 1996 No. of 50 35 45 50 60 60 60 60 27 53 20 25 growers

25 25 52 10 12 5

50

Working Group on Maize Seed Production Costilla

Parame"'rs

Land preparation (ploughing and harrowing)

Seed cost (OP at N17/kg given 2Okglha, hybrid at N45/kg-15kg/ba

Planting cost

Fertili= (OP-4bags of NPK and 2 bags of urea; hybrid-6 bags ofNPI<. 4 urea at1601bag)

Fertilizer application

Herbicide eost (Primex ... -5 lilres-NI600; Gramowne -51iIreS-N2400)

Herbicide application

Harvesting lind threshing

Processing cost

Certification cost

InremaJ quality canll'ol

De<asseling eost and male line removal

Transporlation

Bagging (N7 /bag of Skg=200bags-OP; 300 bags for hybrid)

Storage

Pest prevention at storago-(Phostoxin B 16O/oobe)

Certification rag (No.5/rag) Company label (N \.oo/Label)

A Total cost (excluding treatment with Apron Plus®) Profit at 12% (current interest rate)

Total cost plus profit (excluding lI'eaunent with Apron Plus®)

B Seed tteatment (Apron Plus® N 16/10 g /kg seed)

Cost of production

12% cWTent interest rare on capital

Total cost plus profit (including treatment with Apron Plus®)

Assumptions: Seed yield

Calculated ar 30 N to USI

51

Open Pollinated (Naira)

850

340

70

960

500

4000

500

1200

450

160

320

1000

1400

250

160

100 200

13.090.00 1,570.80

14.660.80

16.000.00

13.090.00

3,490.80

32,580.80

l.00tonne/ha

Hybrid

850

675

70

1600

500

4000

500

1800

675

240

400

1000

2000

2100

300

240

ISO 300

18.030.00 2163.60

20.193.60

24.000.00

18.030.00

5.043.60

47.073.60

1.S0tonnes/ha

Working Group on Seed Distribution Mechanisms in DM Affected States

Introduction

There appear to be various channels of seed distribution from one state ADP to the other before it gets to the grassroots. For instance, in K wara and Kogi states, and many other states, the commercial arm of their ADP is still in charge of seed distribution. But in a few states the Agricultural Input Supply Company is used. However, we agreed to use the two systems side by side for checks and balances with regards to uniform pricing. 1. The accredited sales agents(ASAs) should apply and be screened for their facilities. Then a non-refundable sum of N250.00 as registration fee is recommended while a refundable N3000.00 fee is imposed. These ASAs are located in the local government areas and should sell to farmers at a specific discount.

2. The second arrangement is through the farm services managers (FSMs) who should operate at the zonal headquarters of the ADP.

The FSMs further distribute seeds to store salesmen as requested by local farmers.

Seed Companies I

Farm Services Centers I

Accredited Sales Agents I

Store Sales Men I

Local Farmers

52

Working Group on Logistics of On-Farm Testing/Field Days for Downy Mildew Control

Conclusions

Site Selection. Sites that are accessible should be selected as much as possible, and the mals located on farmers' farms. Lists of locations should be forwarded to the Coordinator, Rice/Maize Center, PMB 5042, Moor Plantation, Ibadan as soon as the trials are planted.

Land Preparation. The land should be prepared by the farmer the way he wants it.

Plot Size. 10m x 6 rows for each treatment.

Planting. Plant between last week of May and 1 st week of June: 5 trials in the fIrst season, 5 trials in the second season, and 10 trials per state.

Spacing. The farmer can use the spacing he is used to at 2 seeds per hill. Farmers can intercrop if they so desire.

Fertilizer application. 2 kg of NPK (lst dose); lkg of urea (2nd dose). ADP will provide the fertilizer where the farmer cannot.

Monitoring. ADPs should provide !he location and date of planting so as to know the time for monitoring. SIDOs of NSS will be involved in the trials.

Kogi and Kwara: Mr Adekanye 0000: Mr lebutu Osun & Oyo: HQ Staff Edo: Mr Edema

Data collection. Yield data will be taken from the 4 central rows.

2 Field days/state. One in the early season, one in the late season. 85-90 days after planting, i.e., when the cobs have been fully formed.

The Maize Association will give an award to !he best farmer in each state, and !he best EA will receive an award.

53

Campaign Communication Messages in Print and Electronic Media by Communication Working Group

The group came up with a two-pronged campaign strategy comprising the use of print and electronic media.

Print Media

The group planned for three types of printed materials to achieve different stages of the campaign's strategy. Two types of posters were designed for the purpose of creating awareness among the farmers about the presence of downy mildew disease of maize. The leaflet is a follow-up to the posters and is a four-page technical publication with simplified information, sequentially arranged on downy mildew disease of maize. Components are as follows:

Posters

a. Poster I shows a full-grown maize plant displaying all the symptoms of downy mildew attack in its advanced stage. Symptoms displayed are half-leaf, narrow and chlorotic leaves, coblessness and "crazy head".

b. Poster II is for farmers whose farms might be at either the initial stage, middle stage or advanced stage of the attack. Pictorial representations of the symptoms at each stage of attack are shown.

Leaflet

Front Page: Full picture of a maize plant with signs of advanced stage of DM attack.

Page I: Pictures of DMR seed, treated seeds, and seed dressing methods, each captioned.

Page 2: Control measures viz, early planting, rogueing, each captioned.

Back Page: Success Story: A farmer smiling at his full grown and well~obbed maize plant.

Technical Guide

• Introduction--history and economic importance of DM • Symptoms • Spread, epidemiology, and disease development • Prevention (including precautionary measures) • Control measures • Summary

The language of production is the locallanguage(s) predominant in each state, subject to a maximum of three languages. Distribution is through the extension agents, and block extension supervisors.

Electronic Media

A 2-voice promotion jingle between an affected farmer and an informed farmer was drafted for production and transmission in the local languages predominant in the affected states.

54

Extension & Training Personnel and Technical Messages

Extension and Outreach Capability by State

Village Kwara Kogi Oyo Osun Ondo Edo Total

No.EAs 122 114 269 202 195 137 1,039

BEAs 21 19 3S 30 22 18 145

SMS 20 21 28 30 25 6 130

No. of maize 23 70 30 60 35 40 258 based SPATIVEA

No. of maize 11 40 15 30 20 10 126 based SPAT/BEA

No. of farmers 14,030 39,900 38,000 60,600 34,125 23,975 210,630 reached thro' SPAT, & field days

No.ofOFAR 40 40

No. of farmers 200 200 reached thro' OFAR

No. to be VEA SMS trained

Kwara 122 20

Kogi 114 21

Oyo 269 28

Osun 202 30

Ondo 195 22

Edo 137 18

Training: At 2 levels MTRM-SMS, ZEO, HOD

FNT-SMS, BEA, YEA, BES

MTRM Training-Preseason

151

755

BES ZEO BEA

23 4 21

32 4 19

35 4 35

35 3 30

45 6 22

22 2 18

MTRM Downy mildew awareness training-During the season

44

440

HQ

12

12

11

11

14

4

FNT-As many as possible depending on messages developed during the MTRM.

55

275

1.595

Video

4

2

2

2

3

2

Technical Messages A. Seed Selection

• Source of seeds: obtain downy mildew-resistant seeds from NSS, cenified agricultural input supply agencies, and seed companies.

• Select high quality seeds. • Genetic purity: seeds must be true to type, of the right size, have good viability, and

be disease and pest free. • Buy only treated seeds.

B. Seed Treatment • Ensure uniform coverage of every kernel of the seed lot • Use correct dose of Apron Plus®-10 grams per 1 kilogram of seed. • Dress only at the point of planting. • Take safety precautions-use of overall, nose guard, and hand gloves. • Do not store dressed seeds for more than 4 weeks.

C. Planting • Plant early, i.e., when the rains stabilize. • Seed rate: 20-25 kg/ha.

D. Field Maintenance • Rogue infected plants as soon as infection is noticed. • Observe field sanitation, e.g., removal of volunteer crops. • Discourage farmers from moving maize and maize plants from infected zones to

infection free zones.

56

Budget for Extension/Training/Communication

No, Description of lIolD Nwne Unit Tolal Remarks orADP cost (N) cost (N)

1 Training Workshop

i) Feeding & Ondo 450.00 2.250.00 5 participants at accommodetion of 150/participant participants Osun 3,000.00 15,000.00 5 atN1.000 for 3 days Oyo 3,000.00 9,000.00 3 .... .. ..

Kwara 3,000.00 15,000.00 5" .... .. Kogi 3,000.00 15,000.00 S .. .... " Edo 1,000.00 3,000,00 1 " " " "

ii) Trensportation- Ondo fuelling of vehicles Osun 1,500.00 3,000.00 2 vehicles at

N I ,500/vehicie.

Oyo 1,500.00 3,000.00 2 verudes@ NI,500/vehicle.

Kwara 2,000.00 4,000.00 2 verucles@ 2,OOO.00/vehicle.

Kogi 3,000.00 6,000.00 2 verucles@ 3,OOO.00/vehicle.

Edo 1,500.00 1,500.00

iii} Registration of Ondo 100.00 500.00 5 participants @ participants NIOO

OSW! 100.00 500.00 .. .. .. .. Oyo 100.00 300.00 3 participants @

NIOO Kwara 100.00 500.00

Kogi 100.00 500.00 5 participants @ NIOO

Edo 100.00 100.00 .. .. .. ..

2 Field Days

i) Radio announcements Ondo 500.00 10,000.00 Cost for 2 field days 10 Slots each Osun 500.00 10,000.00 per field day for Oyo 500.00 10,000.00 2 locations Kwara 500.00 10,000.00

Kogi 500.00 10,000.00 Edo 500.00 4,200.00 16 Slots/field day

ii) Transportation a) Hiring of 3 buses pcr Edo 4,000.00 24,000.00 (Fuelling mclusive

field day for 2 locations Ondo 3,000.00 18.000.00 for Edo State) Osun 3,000.00 18,000.00 Oyo 3,000.00 18,000.00 Kwara 3,000.00 18,000.00 Kogi 3,000.00 18,000.00

57

No. Oes<:rlptlon of Item Name Unit Total Remarks ofAOP cost (N) <ost (X)

b) Fuelling of 3 buses Ondo 1,500.00 9,000.00 for 2 days Oson 1,500.00 9,000.00

Oyo 1,500.00 9,000.00 Kwara 1,500.00 9,000.00 Kogi 1,500.00 9,000.00

iii) Entertainment for Ondo 30.00 30,000.00 500 participants per Oswt 30.00 30,000.00 day for 2 days Oyo 30.00 30,000.00

Kwara 30.00 30,000.00 Kogi 30.00 30,000.00 fdo 22,000.00

3 Eradication campaign

i) Production of radio Ondo 5,000.00 10,000.00 Zlanguages jingles in 3 Osun 5,000.00 10,000.00 2 languages languages Oyo 5,000.00 5,000.00 llenguages

Kwara 5,000.00 15,000.00 3 languages Kogi 5,000.00 15,000.00 3 Janguages Edo 5,000.00 10,000.00 2 languages

ii) Airing of jingles Ondo 500.00 91,000.00 182 Slots 14 slots pcr week Osun 362.00 65,520.00 18Z Slots for 13 weeks (for Oyo 500.00 91,000.00 182 Slots a1llanguagcs) Kwara 350.00 58,800.00 182 Slots

Kogi 500.00 91.000.00 182 Slots Edo 350.00 63,700.00 182 Slots

iii) Posters Onda 8.00 32,000.00 2 langs. (4,000

•• Printing of 6000 Osun 8.00 32,000.00 :opi~)

posters in 3 Oyo 8.00 32,000.00 languages Kwara 8.00 48,000.00 3 (6,000 copies) (2000/languagc) Kogi 8.00 48,000.00 " It "

fda 8.00 32,000.00 2 (4,000 copies)

b. Handbills/lcaOets Onda 3.00 1A,OOO.OO 2 lang. (8,000 4OOI..ootsl Osun 3.00 1A,OOO.OO :O~,es). handbills Oyo 3.00 1A,OOO.OO . . per language Kwara 3.00 36,000.00 3 (12,000 copies (3 languages Kogi 3.00 36,000.00 .. .. II

allowed)

4 Mobile vans campaign

i) Fuelling! maintenance Onda 500.00 10,000.00 One vehicle to be of 2 vehicles for Osun 500.00 20,000.00 used 5 days! Oye 500.00 20,000.00 weeks or 20 days Kwara 500.00 20,000.00 for one month. Kogi 500.00 20,000.00

S8

No. Descriptioll of item Name ofADP cost(N)

il) 2 Drivers' allowance Ondo for 20 days of lb. Osun monlh each. Oyo

Kwara Kogi

ii) FueUing and Ondo acconunodation for Osun two supervisors for Oyo 20 days of !he Kwars monlheach Kogi

5 Production of extension Ondo guide (6000 copies) Osun

Oyo Kwan Kogi

Summary

l.

3.

5.

Training workshop

Ondo N 67,000.00 Osun N 67,000.00 Oyo N 67,000.00 Kwara N 67,000.00 Kogi N 67,000.00

Eradication campaign

Ondo NI57,OOO.00 Osun N131,520.oo Oyo N152,ooO.00 Kwara N157,8oo.00 Kogi NI90,OOO.OO

Production of extension guide

Ondo Osun Oyo Kwara Kogi

N 48,000.00 N 48,000.00 N 48,000.00 N 48,000.00 N 48,000.00

Unit ToI3I Remarks cost (11.')

85.00 1.700.00 One vehicle to be 90.00 3.600.00 used 90.00 3.600.00 90.00 3.600.00 90.00 3.600.00

300.00 6.000.00 300.00 12.000.00 300.00 12.000.00 300.00 12.000.00 300.00 12.000.00

8.00 48.000.00 8.00 48.000.00 8.00 48.000.00 8.00 48.000.00 8.00 48.000.00

2. Field days

Ondo N 2,750.00 Osun N 18.500.00 Oyo N 12,300.00 Kwara - N 19,500.00 Kogi N 21,500.00

4. Mobile vans campaign

Ondo N 17,700.00 Osun N 35,600.00 Oyo N 35,600.00 Kwara N 35,600.00 Kogi N 35,600.00

59

Name of ADP

Ondo

Total

Osun

Total

Edo

Oyo

Summary or DM Control Campaign Budget by State

Description of item

Training workshop

Field days

Eradication campaign

Mobile vans campaign

Extension guide

310,150.00

Training workshop

Field days

Eradication campaign

Mobile vans campaign

Extension guide

300,620.00

Training workshop

Field days

Campaign publicity

Total

Training workshop

Field days

Eradication campaign

Mobile vans campaign

Extension guide

Total

60

Total cost (N)

2,750.00

67,000.00

157,000.00

35,400.00

48,000.00

18,500.00

67,000.00

131,520.00

35,600.00

48,000.00

4,500.00

39,500.00

105,700.00

149,700.00

12,300.00

67,000.00

152,000.00

35,600.00

48,000.00

314,900.00

Name of ADP

Kwara

Kogi

Description of item

Training workshop

Field days

Eradication campaign

Mobile vans campaign

Extension guide

Total

Training workshop

Field days

Eradication campaign

Mobile vans campaign

Extension guide

Total

Note: Contingency N6,5SO.00 Ondo State.

61

Total cost (N)

19,500.00

67,000.00

157,800.00

35,600.00

48,000.00

317,900.00

21,500.00

67,000.00

190,000.00

35,600.00

48,000.00

362,100.00

Annex 1. List of Participants

Name Designation Institution

Adedeji, SA. PAO NRMCIFDA

Adegbuyi, E. N.C. - Seed Certification NSS, Ibadan

Adeniyi,F. Hcad/WIA KogiADP

Adenle, V.O. Visiting Scientist IITA,lbadan

Adenola, O.A. Assistant Director FDA/NRMC,lbadan

Adewumi, M.O. DDTS(Seed) KogiADP

Adeyemi, B.T. DCTO/WIA KWADP

Adigun, I.K. ADAES OyoADP

Afolabi, E.A. Hcad/WIA ODSADEP, Akure

Ajao,A.G. CDOHQ I KwaraADP

Ajayi,EJ. Technical Manager SNCCL, Lagos

Ajayi,J.K. ODSADEP, Akurc SMS, Agronomy

Aje,E.O. DCTO(Seed) KwaraADP

Akindele,O.E. Acting Chief ODSADEP, Akure Communications Officer

Akinnuoye, AF. Research Supervisor liT A, Ibadan

Anwo,F.A. Head of Communication OSADEP,lwo

Aviomoh,R. Chief Seed Officer EdoADP

Ayangbadejo, C.T. Regional Head NSS, lbadan

Bello, 1.0. PAO FDA/NSS, Ibadan

Buraimoh, GJ. Seed Qlty. Control Off. ODSADEP, Akure

Cardwell, KF. DMTF Coordinator lIT A, Ibadan

Ejiga. 0.1. PCDO KogiADP

Fabiyi, J .K. Seed Manager OsunADP

Fajana, L.O. PL-Seed Ind. Dev. NSS,lbadan

Fasuyi, T. Audiovisual Specialist lIT A, lbadan

Gadzama, E.W. Agriculwrist World Bank, Lagos

Idowu,S.O. Ag. H/WlA OsunADP

!ken, J.E. NC-NCMRP IAR&T,lbadan

62

Jebutu,O.M SISD NSS,Akure

Joshua, A. Pioneer Hi-Bred Seeds Zaria Nig.Ltd.

Kim,SK. Maize Breeder IITA,Ibadan

K1ing,J.G. Maize Breeder lIT A, Ibadan

Matuluko. E.O NC- Seed Ind. & Tech Supp. NSS,Ibadan

Nema.N.P. Advisor. NSQP NSS.Ibadan

Obajimi. A.O. Planl Breeder IAR&T,Ibadan

Odebunmi. S.O. DDCS OsunADP

Ogundipe. A.O. N.C. Breeder Seed NSS, Ibadan

Ogungbade. O.

Ojo,T.M Marketing Rep. UAC Seeds, Ibadan

Olaoye. M.O. Chief ExtenSion Officer KwaraADP

Olonilua. FJ. NC-SeedLaw NSS.Ibadan Enforcement

Olowookere.O.M Seed Cert. Off. NSS.Akure

Olwno,A.B. DireclOr, Extension KogiADP

Oluniyi. Ogungbade Chief Res. Officer (Seed) Oyo ADP, lbadan

Omotehinwa, J.B. Communications Officer KogiADP

Onigbogi. 1.0. DAES OSADEP.lwo

Onukwn, D.P. Research Technician UTA,Ibadan

Oyebamiji.O.A. Communications Officer OyoADP

Oyedokun. A.O. Zona! Coordinawr NAERLS. Ibadan

Oyetunde, A. Ediwr. Training IITA.lbadan Malerials

Salami, A.A. ITO KWADP

Sanni,S.O. DDAES ODSADEP, Akure

Shobowale, OJ. NC- Seed Production NSS,lbadan

Soda.BL. Pioneer Hi-Bred Seeds Zaria Nig. Ltd.

Zachmann, R. Training Materials IITA,Ibadan Specialist

63