Positive products for control of rice blast disease

Mwangi J.K, - UOK

Wanjogu R.K,Owilla B.P.O, -MIAD

Introduction• Rice is one of the world’s most important cereal crop and

its protection from disease is vital to the many million dependants on it as their staple food.

• Rice: 3rd most important cereal crop in Kenya ; Consumption: 400,000MT p.a

• Production constraints;• Abiotic : drought and floods, temparature, soil

fertility• Biotic: insect pests, and diseases (Fungal and

bacterial)• Primary constraint;- Rice blast.

• Rice Blast Causal organism Perfect stage: Magnaporthe grisea Imperfect stage(anamorph): Pyricularia oryzae

• The fungus infects plant by the spore germinating and forming an appresorium (a thick fungal cell) on the plant surface and then exerting a haustoria (feeding structure) into the plant cells.

• A minimum of 8 hrs moisture is needed for infection to occur.

• Most plant parts are susceptible to infection except the roots.

.

Symptoms caused by Magnaporthe grisea on rice plants

Collar blast

Neck rot

Panicle blast

Leaf blast

Node symptom

White heads' caused by neck rot

Node blast

Panicle blast

Introduction cont.• Yield losses due to blast;- Approximately 60% - 100% • Rice blast was first reported in Kenya in the 60’s mainly in

the Western regions.• It has also been reported since 2008 in Mwea the main

rice growing area in the country where it caused 20- 30% yield loss.

• The blast problem has threatened rice production and also the national food security.

• Use of resistance varieties against rice blast pathogen alone has been found to be unreliable and sometimes disappointing.

• Breeding for these resistant lines takes time before they reach the farmers.

• It thus seems that chemical control can offer greater promise and will constitute an important weapon in reducing crop losses.

• The objective of the trials is to evaluate the efficacy of different fungicides from different companies in the control of rice blast.

Fungicides presented thro PCPB for trials

COMPANY PRODUCT CATEGORY NO. OF SEASONS COMPLETED

CURRENT STATUS

Green life Jupiter Fungicide 2 Report submitted to PCPBGreen life Witness Fungicide 2 Report submitted to PCPBGreen life Chariot Fungicide 2 Report submitted to PCPBGreen life Goddard Fungicide 2 Report submitted to PCPBGreen life Sacrifido Fungicide 2 Report submitted to PCPBGreen life Defacto Fungicide 1 First season data entry is ongoing

Green life Exempo curve Fungicide 1 First season data entry is ongoing

Green life Absolute Fungicide 1 First season data entry is ongoing

Green life Ransom Fungicide 1 First season data analysis ongoing, second season trial ongoing in the field

Sygenta Score Fungicide 2 Report submitted to PCPBSygenta Amistar Fungicide 2 Report submitted to PCPBSygenta Armure Fungicide 0 First season trial ongoing in the

fieldTop serve Stallion Fungicide 2 Data analysis and report

preparation ongoingGreen life Discovery Fungicide

(Sheath Blight)0 Field preparations in progress

East Africa B. Company

Blastin Fungicide 0 Field preparations in progress

Experimental design • The experiments were laid out in a randomized

complete block design with six treatments replicated three times.

• The treatments consisted of;TREATMENTS

Chemical name TRT1 TRT2 TRT3 TRT4 TRT5 TRT6

50 % of Recommended company rate

Recommended company rate

125% of Recommended company

rate

Standard check

Local check Untreated control

The varieties used were Basmati 370 and Basmati 217

Data at harvest;• Number of tillers per hill• Number of productive tillers/hill• Number of grains/panicle• Number of empty grains/panicle• 1000 grain weight at 14% MC

RESULTSRice blast disease incidence/severity and effect on some yield parameters

Effect on grain yield

0

5

10

15

20

25

30

35

40

45

0

200

400

600

800

1000

1200

0.5lts/ha Stallion 0.75lts/ha Stallion 1.0lts/ha Stallion Topsin @1lt/ha goldazim control

We

igh

t o

f 1

00

0 g

rain

s(gm

)

We

igh

t (g

ms)

FERTILE GRAINS STERILE GRAINS 1000 GRAINS WGT

16

16.5

17

17.5

18

18.5

19

19.5

20

20.5

0

200

400

600

800

1000

1200

1400

0.5lts/ha Stallion 0.75lts/ha Stallion 1.0lts/ha Stallion Topsin @1lt/ha goldazim control

We

igh

t o

f 1

00

0 g

rain

s(gm

)

We

igh

t(gm

)

Fertile grains Sterile grains 1000 Grains weight

Bs 370

Bs 217

Conclusion• From the results;• It is evident that the new fungicides have an effect

on rice blast.• Severity in plots sprayed with the new fungicides

were not significantly different from those sprayed with Bavistin (standard check) and Goldazim (local check).

• Similar trend was observed on the filled grains, 1000 grain weight and biomass per plant.

• The fungicides have therefore been recommended for registration by PCPB for use by farmers in the control of rice blast.

Thank you for listening

End