saving your own vegetable seeds: a guide for farmers

Vegetable SeedsVegetable SeedsVegetable SeedsVegetable SeedsVegetable Seeds

Written by:Sutevee Sukprakarn, Sunanta Juntakool and Rukui HuangKasetsart University

Tom KalbAVRDC—The World Vegetable Center

Saving Your OwnSaving Your OwnSaving Your OwnSaving Your OwnSaving Your Own

A Guide for FarmersA Guide for FarmersA Guide for FarmersA Guide for FarmersA Guide for Farmers

With support from The Asian Development Bank

AVRDC—The World Vegetable CenterP.O. Box 42, Shanhua, Tainan, Taiwan 74199, ROCtel: +886-6-583-7801fax: +886-6-583-0009e-mail: [email protected]: www.avrdc.org

AVRDC—Asian Regional CenterP.O. Box 9-1010 , Bangkok 10903,Thailandtel: +66-2-942-8686, -8687fax: +66-2-942-8688e-mail: [email protected]: www.arc-avrdc.org

© 2005 AVRDC—The World Vegetable CenterISBN 92-9058-144-1

Edited by Tom KalbCover design by Ming-che Chen

CitationSukprakarn, S., S. Juntakool, R. Huang, and T. Kalb. 2005. Saving your ownvegetable seeds—a guide for farmers. AVRDC publication number 05-647.AVRDC—The World Vegetable Center, Shanhua, Taiwan. 25 pp.

AVRDC—The World Vegetable Center is an international not-for-profit organization committed to alleviating poverty and malnutritionthrough research, development, and training.

CCCCC ontentsontentsontentsontentsontents

Acknowledgments .......................................................................................... ii

Foreword ....................................................................................................... iii

Overview of seed saving ............................................................................... 1

Amaranth ....................................................................................................... 4

Bean ............................................................................................................... 5

Beet family (beet, spinach and Swiss chard) ................................................. 6

Brassicas (broccoli, Brussels sprouts, cabbage, cauliflower, Chinesecabbage, kohlrabi, mustard and turnip) .................................................... 7

Carrot ............................................................................................................. 8

Cucumber family (cucumber, melon, pumpkin, squash and gourd) .............. 9

Eggplant ......................................................................................................... 11

Jute ................................................................................................................. 12

Kangkong ....................................................................................................... 13

Lettuce ........................................................................................................... 14

Malabar spinach ............................................................................................ 15

Mungbean ..................................................................................................... 16

Okra .............................................................................................................. 17

Onion ............................................................................................................ 18

Pepper ........................................................................................................... 19

Radish ........................................................................................................... 20

Soybean ......................................................................................................... 21

Tomato .......................................................................................................... 22

Yardlong bean ............................................................................................... 24

References ..................................................................................................... 25

Saving Your Own Vegetable Seeds | iiiii

Many persons contributed to the making of this book. The authors would like to thank Dr.Liwayway M. Engle, Dr. Manuel C. Palada, and Mr. Efren Altoveros of AVRDC for theirassistance in editing. We thank Dr. Surapong Dumrongkittikul and Ms. Kwankate Sangkaewof Kasetsart University as well as Mr. Ming-che Chen and Drs. Engle and Palada of AVRDCfor supplying photos and contributing to the layout of the publication. Finally, the authorsthank the Asian Development Bank for their generous support of our project, including thepublication of this book.

AAAAA cknowledgmentscknowledgmentscknowledgmentscknowledgmentscknowledgments

iiiiiiiiii | Saving Your Own Vegetable Seeds

FFFFF orewordorewordorewordorewordoreword

Saving Your Own Vegetable Seeds | iiiiiiiiiiiiiii

Good seeds are undoubtedly one of the most important materials for farmers. The seedsmust be healthy and, preferably, they must possess all the desirable properties that farmersneed such as high yielding, high quality, and resistances to diseases, insect pests and envi-ronmental stresses.

The Asian Regional Center of AVRDC (AVRDC-ARC) has been conducting training onvegetable production technologies including seed production, seed testing and seed preser-vation at the regional training center in Kamphaeng Saen, Thailand in collaboration withKasetsart University for 24 years. The number of trainees who have participated from Cam-bodia, Lao PDR, Vietnam and Myanmar numbered 205 by the year 2004. The regionaltraining was conducted mainly for extension workers and researchers, and it has contributedto increasing the numbers of trainers in these countries. After going back to their own coun-tries, the graduates of this training program have become resource persons. They engaged inin-country training on vegetable production.

Various kinds of in-country training have been conducted in relation to vegetable produc-tion. As an off-shoot, the production of vegetable seeds is now being conducted in thesecountries. However, it seems that the technologies for seed production have not yet reacheddown to the level of ordinary farmers adequately. Many farmers still need to learn the tech-niques required to produce vegetable seeds by themselves. Seed production of vegetables isnot as simple as it is for many self-pollinated staple crops, including beans and some cerealgrains. Specific techniques are required for every type of vegetable. Aside from this, F

1

hybrid vegetable seeds are now prevailing in the market, and farmers must be informed thatthe seeds obtained from the harvest of these crops cannot be used for sowing future crops.Therefore, the dissemination of seed production technologies based on reliable informationis needed. The manual provided here was written by the teachers of Kasetsart Universityand AVRDC headquarters who have been working together with AVRDC-ARC. This edi-tion is made in an effort to help extension workers who are directly in contact with farmers.I am hoping that this manual will help ordinary farmers and will contribute to the sustain-able development of agriculture through vegetable production in developing countries.

Masaaki SuzukiDirectorAsian Regional Center of AVRDC

Saving Your Own Vegetable Seeds | 11111

Which seeds can be saved?Vegetable seeds can be saved to sow newcrops in the future, but not all seeds are suit-able for saving. Varieties suitable for seedsaving include local varieties that have beengrown in one region for a very long time,self-pollinating crops (for example, beansand peas), and open-pollinated varieties ofsome cross-pollinating crops (for example,pepper, cucumber and carrot).

Commercial F1 hybrid varieties are popu-

lar among many vegetable growers today.However, the seed of hybrid fruits shouldnot be saved, because the F

1 hybrid seeds

were produced by crossing two different par-ent varieties. Seed saved from hybrids willeither be sterile or the plants of the next gen-eration may show wide variation incharacters, uniformity and maturity.

Seed saving involves selecting suitableplants from which to save seeds, harvestingseeds at the right time, and storing them

properly. The seed saving techniques ofmany common vegetables will be introducedin this manual.

Before you start to save seeds, it is nec-essary to know a few things about thereproductive ability of plants. Many veg-etable species produce flowers with the malepart (anther) and the female part (stigma) inthe same flower. These are called perfectflowers (Fig. 1). However, in maize andmost varieties of the cucurbit family (cucum-bers, melons, pumpkins, etc.), the anthersand the stigma are in the same plant but ondifferent flowers. These are called imper-fect flowers (Fig. 2).

Pollination occurs in plants when pollenfrom the anthers of the flower is depositedon the stigma. In some perfect flowers, self-pollination occurs. Lettuce, tomato, and okrahave the stigma so close to the anthers suchthat the slightest wind movement can causethe pollen to drop onto the stigma withinthe same flower. In peas and beans, self-pol-

OOOOO verview of seed savingverview of seed savingverview of seed savingverview of seed savingverview of seed saving

Fig. 1. Perfect flower of eggplant: the stigma(green) is surrounded by anthers (yellow)

Fig. 2. Imperfect flowers of squash: femaleflower with exposed stigma (left) and maleflower with exposed anthers (right)

22222 | Saving Your Own Vegetable Seeds

lination occurs even before the flower opens.

Other types of perfect flowers requirecross-pollination. An external pollinatorsuch as an insect is necessary. Onion, car-rot, cabbage, and radish, for example,belong to this type.

Plants with imperfect flowers requirewind or insects such as bees to transmit pol-len from the anthers of the male flowers tothe stigma of the female flowers. Maize, forexample, is cross-pollinated by wind, whilecucurbits are cross-pollinated by bees.

How to keep seeds pure?Keep in mind that natural cross-pollinationcan always happen to some extent under afield situation, even in self-pollinatingplants. It often occurs when pollen grainsstick onto the bodies of insects visiting flow-ers, and then carry the pollen grains to thenext flower they visit.

Isolation in distance. Pure seeds can beproduced by leaving enough distance be-tween two or more varieties to preventcross-pollination by insect or wind-blownpollen. How far apart differs among veg-etables; this will be described for eachvegetable in the following chapters.

Bagging. When only a small amount ofseed is needed, cover the unopened flowerswith a paper bag. This is applicable for cropswith a high but not 100% rate of self-polli-nation, such as pepper and eggplant. Youcan also bag the flowers of cucurbits (Fig.3); in this case, both male and female flowershould be bagged, but hand-pollination isrequired.

Caging. Cages can be used for vegetablesthat flower over a long time or to preventinsects from transmitting pollen from twonearby varieties of the same crop (Fig. 4).You can use bamboo rods stuck in theground to make an arched tunnel and cov-ered with nylon mesh. Because the cage willexclude all insects, you may need to handpollinate the plant to ensure seed set, or youcan introduce bees into the cage if they arecross-pollinated species.

What is the best way to storeseeds?After saving your seeds, it is important tokeep them alive for future use. Newly har-vested seeds should not be immediatelystored in a plastic bag because the moisturecontent of the seed is still high and will leadto deterioration.

Fig. 3. Bagging bitter gourd flower for hand pol-lination

Fig. 4. Isolation of pepper selections in nylonnet tunnels


Before keeping seeds in the storage, seedsshould be dried. Keep in mind that seedsare alive—but they breathe very slowly. Tokeep seed alive for a long time, keep themunder low temperature and low humidityduring storage.

Humidity. Seeds will absorb moisturefrom the storage environment. High humid-ity levels cause seed to increase theirrespiration rate and use their stored energy.Make sure your seeds are dry enough (seedmoisture content around 7–8%) before stor-age, and keep them in an air-tight container,such as a screw-top jar (Fig. 5).

Darkness. Exposure to sunlight willshorten the life of seeds. Use dark-color jarsor nontransparent containers to protect seedfrom sunlight. If using clear jars, place themin paper bags to shield out sunlight.

Temperature. For most vegetable seeds,a temperature below 15 °C is ideal. You cankeep the seeds in an air-tight container andplace the container in the refrigerator. Forshort-term storage, keep the seeds in a cooland shady dry place.

Fig. 5. Seeds stored in air-tight containers toprevent them from absorbing moisture

Most vegetable seeds can be safely storedfor at least three to five years. Place seedsin manila envelopes, cloth or mesh bags,plastic containers, or foil envelopes. Thebest containers are air-tight, such as a sealedglass jar, metal can, or foil envelope. Labeleach container carefully. Note the names ofthe line or variety, the year, and any otherinformation you feel is valuable. Store seedsin a cool, dry place.


ProductionAmaranth (Amaranthus spp.) is an impor-tant food crop in Africa and Asia, especiallyfor subsistence farmers. It is a fast-growingcrop that easily grows on a wide range ofsoils and climates. The plant prefers tem-peratures between 25 and 30 °C.

There are many Amaranthus spp. grow-ing as weeds (for example, A. spinosus)around crop fields. For these reasons, localvarieties are usually mixed populations.

Seed crops are often produced usingtransplants. Seedlings with desirable leafand stem characteristics are transplantedabout three weeks from sowing and spaced45 cm apart in rows spaced 60–80 cm apart.Plants with a small apical inflorescence maybe pinched four weeks after sowing to en-courage production of secondary shoots.

IsolationAmaranth is mainly wind pollinated. A mini-mum isolation distance of 1000 m betweenvarieties is recommended. Keep plantingsfree from related weeds to prevent cross-pollination.

SelectionPlants may be rogued as young plants, re-moving types with undesirable or off-typecolor, size or leaf shape. Plants should berogued again just before flowering, againremoving off-types. Once flowering begins,plants with off-type flowers should bequickly removed.

AAAAA maranthmaranthmaranthmaranthmaranth

HarvestingA lightening or yellowing of foliage coloris an indication that seeds are beginning tomature (Fig. 6). Types with an apical inflo-rescence are usually harvested once. Typeswith several side shoots are harvested sev-eral times as the seeds mature. The harvestedseed stalks are placed on a clean tarpaulinor into very fine mesh nylon bags and al-lowed to dry in the shade.

ProcessingSeeds are easily threshed by hand. Thethreshed seed is cleaned by winnowing.

Fig. 6. Maturing seed stalks of amaranth


ProductionSeed production of French or common bean(Phaseolus vulgaris) is possible in the trop-ics as long as the maximum day temperaturedoes not exceed 30 °C at the time of flower-ing. For best results, French bean should begrown during a season where temperaturesbegin warm but then gradually decrease.Under these conditions, seeds will germi-nate well in the warm soil and set pods astemperatures decrease. Dry weather is pre-ferred while pods mature.

IsolationFrench bean is a self-pollinating crop andno isolation is required.

SelectionHarvest seeds that grew on healthy, vigor-ous growing, high yielding plants (Fig. 7).Avoid harvesting seed from off-type plantsas well as plants affected by diseases.

HarvestingPods are harvested when they have turnedyellow but are not yet completely dry. Theinner seeds will be firm, well developed, andbeginning to loosen inside the pods. Har-vesting is often done in the morning to avoidlosses due to shattering.

ProcessingDry the pods in the sun and then place in ashelter for 1–2 weeks of curing. Pods arethreshed by hand, being careful not to in-jure or split the seeds (injured seeds willgerminate without primary leaves and growpoorly). Seed is further cleaned and driedafter threshing.

Fig. 7. Maturing bean pods

BBBBB eaneaneaneanean


BBBBB eet Familyeet Familyeet Familyeet Familyeet Family

ProductionThe beet family (Chenopodeae) includesbeet and Swiss chard (Beta vulgaris) as wellas spinach (Spinacia oleracea). Plants aregrown as an annual for edible leaves and asa biennial for seeds. The crop prefers coolweather but is widely adaptable. Seed pro-duction can be done in cooler regions of thetropics and subtropics. Two methods areused:

Seed to seed. Sow seeds in late summer.Mulch in late fall to ensure winter survival.The following spring, select the finest youngplants and transplant using 45-cm spacing.The optimum transplant diameter is 2.5 cm.The tops may be trimmed, but not the root.

Root-to-seed. Harvest first-year roots infall. Select desirable roots and trim tops 2–5 cm above root. Store at 4 °C in a humidlocation. Replant in early spring at 45-cmspacing with tops just showing above soil.

In either method, only transplant the mostdesirable plants. Stalks may become tall(over 1 m) and are susceptible to lodging;support with staking if needed.

IsolationThe flowers are perfect and borne in groupsof 2–3 in axes of leaves. Flowers producepollen that is carried long distances by wind;thus, it is highly cross-pollinated. Isolatedifferent varieties 500–1000 m apart. Beetand Swiss chard will cross-pollinate so iso-late these as well. Chenopodium album(lambsquarters) should be removed from thearea to prevent cross-pollination.

SelectionRogue out off-types taking into consider-ation the shape and color of leaves and roots.Plants that bolt and go to seed early shouldbe removed. Save seed from at least sixplants to prevent inbreeding.

HarvestingSeed does not ripen uniformly on the plantand sheds easily when mature. Cut stalkswhen most flowering clusters have turnedbrown and stalks have turned yellow anddried—the first seeds are shed at this time.

ProcessingStore stalks in a cool dry location for 2–3weeks to encourage further seed ripening.Do not heap stalks on top of one anothersince this causes seeds to ferment. Handlestalks as little as possible since seeds shedeasily. Small quantities of seed can bestripped by hand as seed matures. Largenumbers of stalks can be put into a bag andbeat with a stick. Chaff is winnowed away.

Fig. 8. Seed stalk of beet

(beet, spinach and Swiss chard)(beet, spinach and Swiss chard)(beet, spinach and Swiss chard)(beet, spinach and Swiss chard)(beet, spinach and Swiss chard)


ProductionBrassicas (Brassica spp.) are one of the mostimportant vegetable groups in the world.Most varieties are grown as temperate bi-ennial crops, but tropical annual types areavailable. Brassicas prefer a cool climateand temperature is the most important fac-tor for seed production. Seed can beproduced either by the head-to-seed methodor seed-to-seed method. The following de-scribes the latter method, which is used fortropical varieties that require little or no coldweather to induce flowering.

The planting time is critical. The cropshould be raised such that the plants facethe coldest temperature at the time of matu-rity or head formation. A long cool seasonis also needed for seed pod development.Crops are typically sown/transplanted inearly to mid-fall so that plants are headingin late fall, blooming in early winter, anddeveloping seeds through the rest of winter.

Special techniques may be used to facili-tate the emergence of seed stalks. Forcabbage, an “X” crosscut is made at the top

of the mature head, being careful not to dam-age the growing point of the inner core. Ascooping slice may be done to the maturecurd of cauliflower. The tops of matureBrussels sprouts plants are clipped to pro-mote flowering. Other tropical brassicas willreadily produce flowers. Seed stalks mayrequire staking for support.

IsolationAll brassicas will cross with each other.Cabbage, cauliflower, broccoli and Brusselssprouts cross readily with each other, as doradish, mustard, Chinese cabbage and tur-nip. Cross-pollination is done by honeybees(Fig. 9) and an isolation distance of 1000 mbetween varieties is recommended.

SelectionOff-type plants can be removed at any time.Most growers rogue the field at the time ofhead/curd maturity so they can see the size,shape and firmness of heads/curds.

HarvestingBrassica seed shatters easily. Harvesting isdone carefully when 60–70% of the podshave turned brown and most of their innerseeds are light brown and firm.

ProcessingHarvested seed stalks are cured for 1–2weeks. Pods are then threshed with sticksand sifted by hand. Seed is brittle and shouldnot be crushed when handled. Seed is driedin partial sun, then cleaned and stored.

BBBBB rassicasrassicasrassicasrassicasrassicas(broccoli, Brussels sprouts, cabbage, Chinese(broccoli, Brussels sprouts, cabbage, Chinese(broccoli, Brussels sprouts, cabbage, Chinese(broccoli, Brussels sprouts, cabbage, Chinese(broccoli, Brussels sprouts, cabbage, Chinesecabbage, kohlrabi, mustard and turnip)cabbage, kohlrabi, mustard and turnip)cabbage, kohlrabi, mustard and turnip)cabbage, kohlrabi, mustard and turnip)cabbage, kohlrabi, mustard and turnip)

Fig. 9. Honeybee pollinating brassica flower


ProductionCarrot (Daucus carota) seed production re-quires two years. Roots form during the firstyear and then require a cold period (at least10 weeks of temperatures below 15 °C) tostimulate flowering and seed production.Two methods of production are used:

Seed-to-seed. Pencil-sized or larger rootsare left in the ground overwinter. In late fall,plants are thinned to 5 cm apart, tops arecut back to 5 cm high, and mulched. Oncetemperatures rise in spring, the mulch is re-moved and leaves will regrow. After severalweeks, a seed stalk will appear. Superiorplants are thinned to stand up to 75 cm apart.

Root-to-seed. Harvest eating-sized rootsfor replanting in early spring. Clip tops to 5cm and store at 4 °C in a humid location orlayered in sawdust or sand. Replant roots75 cm apart with soil just covering shoul-ders. This method is most reliable and allowsfor inspection of roots for seed production.

IsolationCarrot plants produce perfect flowers (Fig.10) that are pollinated by insects. Separate

different varieties 800 m apart. Remove wildcarrot weeds since they will pollinate withcarrot.

SelectionRogue off-types taking into considerationthe root color and shape, plant habit, andplant vigor. Plants that bolt and go to seedearly should be removed. Save seed frommany carrots to maintain crop vigor.

HarvestingThe seed turns brown 6 weeks after polli-nation (Fig. 11). Before the seed shatters,cut and place umbels into paper bags to drycompletely. Late-season rains will reduceseed quality. For small amounts, handpickeach umbel as it dries brown. Large amountsof seed can be harvested by cutting the en-tire stalk as umbels begin to dry.

ProcessingAllow seed to mature in a cool, dry locationfor an additional 2–3 weeks. Seeds can beremoved by hand-beating or rubbing umbelsbetween hands. Winnow to clean. Removespines from dry seed by rubbing.

Fig. 11. Cluster of mature seeds

CCCCC arrotarrotarrotarrotarrot

Fig. 10. Cluster of carrot flowers (umbel)


CCCCC ucumber Familyucumber Familyucumber Familyucumber Familyucumber Family

ProductionThe cucumber family (Cucurbitaceae), com-monly referred to as ‘cucurbits’, includescucumbers, melons, squashes, pumpkins,and gourds. They are all warm season cropsand very susceptible to frost. Many cucurb-its are susceptible to foliar diseases thatattack plants during periods of high humid-ity and rainfall. Therefore, regions havinghigh temperatures and low humidity areideal for the production of cucurbit seeds.

IsolationMost cucurbit plants produce separate maleand female flowers on the same plant. Fe-male flowers can be identified by locatingthe ovary (a small looking cucumber, melon,gourd, etc.) at the base of the flower (Fig.12). The flowers are insect-pollinated, andeasily cross within species. However, seedsavers can grow more than one variety at a

time in a single location by using hand pol-linating techniques:

Hand pollination. Cap or bag female andmale flower buds on the same plant ornearby plant of the same variety. Then se-lect male flowers when they bloom, turnover their petals to expose their anthers, andgently roll the anthers over the stigma of thejust bloomed female flowers (Fig. 14); youcan see a layer of pollen has been transferredon the stigma. After pollination, cap or bagthe female flower again to exclude insects(Fig. 15). Mark the pollinated female flowerby wrapping a string to the pedicel.

(cucumber, melon, squash, pumpkin and gourd)(cucumber, melon, squash, pumpkin and gourd)(cucumber, melon, squash, pumpkin and gourd)(cucumber, melon, squash, pumpkin and gourd)(cucumber, melon, squash, pumpkin and gourd)

Figs. 12, 13. Female (left) and male (right) flow-ers of squash

Figs. 14, 15. Pollen on anther of male flower isrolled onto stigma of female flower (left) andthe female flower is bagged (right)

SelectionSelect early flowering, vigorous plants.Hand-pollinate the female flowers located10–20 nodes from the base of the plant. Re-move any deformed fruits.

HarvestingThe fruits should be left to fully ripen andturn color. The fruits of luffa and bottlegourd should be left on the plant until theydry (Fig. 16). For cucumbers, fruits will turn


brownish color (Fig. 17). Bitter gourd fruitswill turn orange. Some wax gourds will becovered with a pale-white powdery wax onthe surface of the fruit. After harvest, thefruits can be kept in a shed for a couple ofweeks to allow the seed to further ripen.

ProcessingFor ‘wet seeds’ such as cucumber, waxgourd, bitter gourd and melons, cut the fruitlengthwise and scrape seeds out with aspoon (Fig. 18). Allow seeds and the jelly-like surrounding liquid to sit in a containerat room temperature for 1–2 days (Fig. 19).Fungus may start to form on top. Stir daily.The jelly will dissolve and good seeds willsink to bottom while remaining debris andimmature seeds can be rinsed away. Spreadseeds on a paper towel or screen until dry.

For ‘dry seeds’ such as luffa and bottlegourd, keep the seeds in the fruit until theynaturally separate from the flesh. This canbe identified when you shake the fruit, thesound of seeds moving inside is heard. Cutoff the bottom of the fruit and shake theseeds out, winnow to clean the remainingchaff, then place the seed on a screen forfurther drying before storage.

Figs. 17–19. Wet seed extraction: mature cucumber (left), seed extraction (center), and ferment-ing seed (right)

Fig. 16. Mature luffa gourd fruits


EEEEE ggplantggplantggplantggplantggplant

ProductionEggplant (Solanum melongena) is a warmseason crop. It requires a long and warmgrowing season for successful production.It is more susceptible to lower temperaturesthan tomato and pepper. A day temperatureof 25–32 °C and a night temperature of 21–27 °C are ideal for seed production.

IsolationEggplants produce perfect flowers, whichmay be cross-pollinated, but self-pollinationis more common. The extent of naturalcrossing depends upon insect activity. Toavoid this, isolate each variety by 20 m orwith another tall, flowering crop. Anotherway is to bag a few flowers from each plantto exclude insects. Tie the paper bag ontothe flowers before they open and remove assoon as the fruits are set. If there is only onevariety of eggplant being grown, isolationis not needed.

SelectionSelect the most vigorous and healthy plants,mark fruits on the second branch, and leavethem until they are fully mature. Keep oneor two fruits from one plant and several fruitsfrom different plants of the same variety tomaintain crop vigor.

HarvestingHarvesting is done when fruits are fully ripe(the skin of fruit turns brownish-yellow ingreen varieties or brownish in purple vari-eties) (Fig. 20). Harvest and store the fruitsin a shed for a week until the fruits get soft.

ProcessingThe outer covering is peeled off and the fleshwith the seeds is cut into thin slices (Fig.21). These are then softened by soaking untilthe seeds are separated from the pulp. If thematerial is allowed to stand overnight in thiscondition, the separation of seeds from thepulp becomes easier. After separation, theseeds are dipped into water. The plump seedswill sink to the bottom. The seeds shouldthen be dried on a mesh for a couple ofweeks in a cool, dry place before storage.

Fig. 21. Mature eggplant cut into small piecesfor fermentation and seed extraction

Fig. 20. Fruits at harvest


ProductionNative to Africa, jute (Corchorus spp.) isnow cultivated over a wide range of envi-ronments today. The adaptable plant growsin humid to semi-arid areas throughout thetropics and subtropics. Jute responds espe-cially well to warm, humid weather and isoften grown near riverbanks. Jute growswell in many soil types.

Flowering is usually induced by short-dayconditions; however, there is diversityamong jute species in their daylength re-quirements for flower induction. Plantsbecome taller and wider during the summer.

IsolationJute plants easily cross-pollinate with eachother in the open field. Different varietiesshould be spaced 1000 m apart. Alterna-tively, varieties can be isolated using netcages. Insects are not necessary for seed re-production inside the net cage.

SelectionSelect plants that are uniform in appearance,healthy and vigorous (Fig. 22). Cover flow-

ers before they open to protect them frombeing contaminated by pollinating insects.

HarvestingAmong the more than 15 species ofCorchorus, two are most common: C.olitorius and C. capsularis. The former pro-duces long capsules while the latterproduces round capsules (Figs. 23, 24). Bothtypes of capsules are harvested when fullymature but before seeds begin to shatter.

JJJJJ uteuteuteuteute

Fig. 22. Healthy and vigorous jute plant withseed capsules

ProcessingDry the capsules under shade. The seeds canlater be separated from capsules easily.

Figs. 23, 24. Popular species Corchorusolitorius (top photo) and C. capsularis (bottomphoto) are closely related, differing mainly inpod shape


ProductionKangkong or water convolvulus (Ipomoeaspp.) can be grown successfully both as aleafy vegetable crop or for seed productionunder tropical conditions. For seed produc-tion, kangkong prefers a long period ofwarm weather and good irrigation.Kangkong can be planted on any type of soil,but prefers a slightly acidic soil as long asthere is adequate sunlight and water. Low-land plantings give higher seed yields thando upland plantings, but take 5–6 monthsto complete the seed cycle.

IsolationKangkong is considered to be a self-polli-nated crop, but cross-pollination may occur.Isolate varieties 100 m apart.

SelectionSelect plants that are vigorous, disease-freeand uniform in plant characteristics.

HarvestingWhen seed pods are mature (Fig. 25), up-root plants when dry weather is expectedfor several days.

ProcessingRemove plant roots with a hoe, and keepplants in the field for a few days to ensurethat all the seeds will mature at the sametime. The plant mat will then curl into a loosebundle. Each day, turn the bundles severaltimes so they dry uniformly (Fig. 26). After3–4 days of drying, the plants should be fullydry and ready for threshing. Use an appro-priate mechanical thresher, such as a beltthresher (Fig. 27). After threshing, the seedshould be cleaned by winnowing.

StorageKangkong seed will store for up to twoyears, a shorter time compared to most veg-etable crops. Storage pests are a problem ifseed moisture content is high.

KKKKK angkongangkongangkongangkongangkong

Figs. 25–27. Mature seed pods (left); rolling plants seed plants into loose bundles for drying(center); mechanical threshing of dried plants (right)


ProductionLettuce (Lactuca sativa) can be grown eas-ily as a vegetable crop in a cool climate. Asa seed crop, it is a quantitative long-dayplant, especially for headed types. It is ad-visable for seed savers to produce only leaflettuce seeds. They require warm tempera-tures (26 °C or higher) to bolt and set seed.

IsolationLettuce produces perfect, self-pollinatingflowers. But a small amount of natural cross-pollination can occur—from 1–6% whentwo varieties are grown side by side. A sepa-ration of 2–3 m or the establishment of atall crop such as maize between differentvarieties is sufficient to reduce outcrossing.

SelectionSelect the best plants at the edible stagewhen you normally harvest for consumptionand mark them by putting a tag into the fieldnear each selection. Early bolting plants arenot usually kept for seeds because the seedsfrom the early bolting plants will also pro-

duce poor quality lettuce for consumption.Plants for seed production may need to bestaked for support (Fig. 28).

HarvestingWhen two-thirds of the flowers of the stalkare turning fluffy white, about 2–3 weeksafter flowering, the seed can be harvestedfrom single plants by shaking their headsinto a canvas bag. This can be done every2–3 days, or you can put the whole plant ona mat under shading. The seed will continueto ripen and shatter.

ProcessingAfter completely dried with white pappis,seed heads are rubbed with hands to removeseeds. If necessary, separate seeds from chaffby winnowing.

StorageLettuce seed loses its viability quicker thanmost vegetable crops. Under ideal cool anddry conditions, seeds may maintain their vi-ability for up to 3 years.

Fig. 28. Staked plants

LLLLL ettuceettuceettuceettuceettuce

Fig. 29. Shattering seeds


ProductionMalabar spinach (Basella spp.), also knownas Ceylon spinach and Indian spinach, is aclimbing perennial plant. The vine is suc-culent with tender leaves.

Malabar spinach grows well in hot, hu-mid climates and is adaptable to most soils.Trellised plants work best from the point ofview of flower induction, fruit harvestingand crop management (Fig. 30). Short days(13 hours or less) are required for flower-ing.

HarvestingHarvest mature fruits with dark purple color(Fig. 31). The vines sometimes turn brownor yellow at this stage. Fruits may be har-vested singly or in clusters.

SelectionSelect seed from healthy, vigorous growingplants with uniform plant habit.

IsolationIt appears to be a self-pollinated speciesjudging from the characteristics of its flow-ers and performance at AVRDC.

ProcessingTwo methods may be used. One option is toremove the seed coats by washing with tapwater, followed by drying of seeds in thesun.

The alternative method is to dry the fruitswith their seed coats attached. Fruits arejuicy and if drying is incomplete the seedsturn bad. Seeds are subsequently threshed,cleaned by winnowing, and later dried morecompletely in the sun.

MMMMM alabar spinachalabar spinachalabar spinachalabar spinachalabar spinach

Fig. 30. Malabar spinach growing on a trellis

Fig. 31. Flowers and mature fruits


MMMMM ungbeanungbeanungbeanungbeanungbean

ProductionMungbean (Vigna radiata) can be grown allyear round but for seed production it shouldbe planted in the dry season or late rainyseason. Growing mungbean after the rainyseason is usually the most suitable time;however, you should follow the recom-mended cultural practices of the extensionoffice in your own location.

IsolationMungbean is a self-pollinated crop, butsome cross-pollination can occur. An isola-tion distance of 3 m is usually enough.

SelectionOff-type plants should be removed as plantsdevelop. Seed should be harvested from dis-ease-free, vigorous plants.

HarvestingHarvest pods when they have matured andturned dark (Fig. 32) and before they startshattering (Fig. 33). Small areas are usuallyharvested by hand. For plantings that ma-ture over a wide interval of time, harvestingmay need to be carried out two or threetimes.

ProcessingThreshing must be done as soon as the podsare dry. Beat pods with a stick until podsare opened, or put dry pods in a burlap bag,place the bag on the floor, and walk on it.Remove any foreign materials by winnow-ing. Sun dry for 3–5 days. Collect only goodseeds (free from diseases, seed coat crack-ing, split, or immature). If using a threshing

machine, adjust the speed of the machine inorder to avoid seed damage.

Fig. 32. Mature pods ready for harvesting

Fig. 33. Shattered pods


ProductionOkra (Abelmoschus esculentus) can begrown on a wide range of soils with gooddrainage, but sandy loam soils are preferred.Temperatures between 27–30 °C promoterapid and healthy seedling development.Seeds will not germinate below soil tem-peratures of 17 °C. Seeds should be soakedin water for 24 hours before sowing. Plantsgrow well in raised beds (20–30 cm high).

IsolationOkra flowers (Fig. 34) are often cross-pol-linated by insects. An isolation distance of500 m or more is recommended. An alter-native method of keeping seed pure is tobag the flower buds and hand-pollinate onceflowers have opened.

SelectionPlants for seed multiplication can be selected

before flowering, taking into considerationthe vigor and habit of the plants. Once flow-ering begins, plants with off-type flowersshould be removed. After the first pods aredeveloped, remove plants with off-typepods. Plants with viral symptoms should beremoved as soon as symptoms appear.

HarvestingThe okra pods mature in a sequence fromthe base of the plant toward the top (Fig.35). The pods have tendency to split alongthe suture when they are dried out. Exposedseeds may be damaged by rain or may dropto the ground; therefore, the pods must beharvested as soon as they have become fullymature (brown color) and before shattering.

ProcessingPods are easily hand threshed.

Fig. 34. Okra pod and flower

OOOOO krakrakrakrakra

Fig. 35. Pods maturing from the base of theplant


OOOOO nionnionnionnionnion

ProductionOnion, Allium cepa, is one of the mostwidely cultivated vegetables in the world.Onion forms its bulb in the first year andproduces seed in the second year. Tempera-tures around 20–22 °C favor vegetativegrowth while temperatures around 12 °Cfavor seed stalk formation. Onion flower-ing is sensitive to daylength—for mostvarieties grown in the tropics, short days areconducive to seed production. One bulb canproduce 20 or more stalks and may be inbloom for over 30 days. Onion producesperfect flowers, most of which are cross-pollinated. Two methods of producing seedare used:

Seed-to-seed. Plant seeds in summer. Im-mature onions are more winter hardy thanlarger, full-grown bulbs. Mulch in late fallto ensure winter survival. Thin to 30-cmspacing in the spring.

Bulb-to-seed. Harvest in the fall and se-lect the largest bulbs (which naturallyproduce more seed). Clip tops to 15 cm andcure for three to four weeks. After the bulbs

are dried, store for at least 2 weeks at 4 °Cin a dry, airy location (a refrigerator is ideal).Before replanting, slice off the top one-fourth of the bulb to promote sprouting.Space bulbs 30 cm apart and cover with 2cm of soil.

IsolationIsolate from other flowering varieties at least1000 m apart. Cross-pollination is per-formed by insects (Fig. 36). An alternativemethod of isolating superior plants is toplace cages over them and introducing pol-linators into the cages.

SelectionIn using the bulb-to-seed method, replantonly disease-free bulbs that are true-to-type.Discard doubles or long, thick-necked bulbs.

For bulbs preparing to flower, remove anytypes of undesirable shape or color; do thisbefore flowering begins. Save seeds fromseveral plants to maintain crop vigor.

HarvestingClip umbels as soon as most flowers havedried and before seeds begin shattering.Some growers harvest when the seeds areexposed in 10% of the umbels.

ProcessingFully dried flowers will drop clean seedsnaturally. For small amounts, rub remain-ing flowers to free seeds. For larger amounts,rub heads over screens. Winnow to removeremaining debris. Allow to dry in cool, drylocation for up to 2–3 weeks. Frequently stirthe seeds. Artificial drying is often used.Fig. 36. Insects pollinating onion flowers


ProductionPepper (Capsicum annuum) grows best inthe dry season with temperatures in the rangeof 21–33 °C. The night temperature is espe-cially critical; generally, plants will not setfruits if night temperatures remain above30 °C. Ideally, select a field where the pre-vious crop was a legume or a cereal. Avoidfields where the previous crop was sweetpotato or a solanaceous crop (tomato, pep-per, eggplant, and white potato). Thisprevents the build-up of diseases and insects.

IsolationPeppers produce perfect, mostly self-polli-nating flowers. Solitary bees will pollinateif other more desirable pollen is not avail-able in the area. Most growers will getsatisfactory results if different varieties areseparated by 20 m or with another tall, windbreaking crop. Closing the flower bud witha cotton ball when the distance of isolationis not sufficient is an ideal method to pre-vent cross-pollination.

SelectionThe earliest maturing and more attractiveplants should be marked and inspected dur-ing growth. Select healthy, attractive fruitsfor seed saving. Seeds from off-type plantsor fruits should not be saved.

HarvestingHarvest mature, fully-ripe peppers for seed.Most peppers turn red when fully mature.

ProcessingPepper seeds may be extracted from freshfruits (Fig. 37) or from fruits that have beendried in the sun for a few days (Fig. 38).Seeds may be removed by hand or extractedby grinding the fruits and separating theseeds from fruits with a series of waterrinses. Spread the seeds on a screen for dry-ing under shade for 2–3 days but bring theminside every evening.

PPPPP epperepperepperepperepper

Fig. 37. Sweet pepper cut for fresh seed ex-traction by hand

Fig. 38. Chili pepper prepared for dry seed ex-traction


ProductionRadish (Raphanus sativus) is a member ofthe cabbage family and grown worldwide.The harvested roots, prized for their pun-gent taste, come in a wide variety of colors,shapes and sizes. There are two major types.First, there are the biennials of temperateorigin that require a cold period for flower-ing. These include the Japanese, Americanand European radishes. Second, there areradishes of tropical origin that do not requirea cold period for flowering.

Radish grows best in a cool dry climate.Temperatures above 32 °C cause the stigmato drop and the pollen may fail to germi-nate. Two methods are used to produce seed:

Root-to-seed. Fully mature roots areharvested and selected for type (Fig. 39).The upper one-third of the root is cut andreplanted at a spacing of 45 × 30 cm.

Seed-to-seed. Fall-winter plantings areallowed to go to seed naturally. Plants arecarefully thinned to stand 45 × 45 cm apart.

IsolationRadish flowers are cross-pollinated by in-sects, primarily honeybees. Isolationdistances of 1000 m or more are recom-mended. Related weeds, notably wild radish,wild turnip and wild mustard, must be re-moved to prevent cross-pollination.

SelectionIn the root-to-seed method, foliar character-istics, root shape, size, skin and flesh colors,pungency, pithiness and bolting behavior areconsidered. Hairy or forked roots and early

bolting plants are removed. Selection ismore difficult in the seed-to-seed methodbecause one cannot see the entire root. Nev-ertheless, growers using this method shouldaggressively rogue out undesirable plantstaking into consideration the same factorsas with the root-to-seed method.

HarvestingThreshing seeds from pods are difficult.Allow the plants to mature fully; then bringthem to the threshing floor for drying.

ProcessingThreshing is done by hand-beating withsticks. The seed is then dried further.

RRRRR adishadishadishadishadish

Figs. 39, 40. Radish roots (top) and ripeningseed pods (bottom)


ProductionSoybean (Glycine max) grows well in well-drained, loamy soils. The minimum soiltemperature for germination is 13 °C. Theoptimum time for planting soybean for seedproduction is usually in the dry season (De-cember) or late rainy season (August);however, please follow the recommendedcultural practices in your own country.

IsolationSoybean is self-pollinating; cross-pollina-tion by insects is possible, but rare. Noisolation is required.

HarvestingWhen soybean matures, the leaves turn yel-low and drop, pods become dry, and seedslose moisture (Fig. 41). Harvesting shouldbe done just before pods begin to shatter;the plants may be cut at the ground level,tied up to a bunch or put in a mesh bag, thendried in the sun for 3 days.

til pods are opened, or put dry pods in a bur-lap bag, place the bag on the floor, and walkon it. Remove any foreign materials by win-nowing (Figs. 43, 44). Dry in the sun for3–5 days. Collect only good seeds (free fromdiseases, seed coat cracking, split, or imma-ture). If using a threshing machine, adjustits speed to avoid seed damage.

StorageSoybean seed does not keep well in storagecompared to the other legumes. The germi-nation rate drops rapidly under roomtemperature conditions, especially in thetropics. If cool storage is unavailable, placeseed in an air-tight container and add burnedlime (calcium oxide) at the rate of 20–30%(w/w). Keep seed at room temperature.

SSSSS oybeanoybeanoybeanoybeanoybean

Fig. 41. Pods ready for harvesting

ProcessingThreshing must be done as soon as the podsare dry. Beat pods with a stick (Fig. 42) un- Figs. 43, 44. Winnowing to remove chaff

Fig. 42. Threshing pods with a stick


TTTTT omatoomatoomatoomatoomato

ProductionTomato (Lycopersicon esculentum) growsbest in the dry season under day tempera-tures of 21–25 °C and night temperaturesof 15–20 °C. Vines will struggle to set fruitif temperatures exceed 30 °C. Humidity lev-els higher than 60% at the time of fruitmaturity will increase disease problems andreduce seed yields. Seed production duringthe rainy season leads to poor seed quality.Avoid fields where the previous crop wastomato; this prevents the new seed crop frombeing contaminated with seeds from volun-teer tomato plants. Growing tomato afterpaddy rice reduces the incidence of diseasesand nematodes. Training of tomato plantsgenerally results in early ripening, fewer dis-eases, higher yields and better seed quality.

IsolationIsolation of plants is usually not needed anda single plant can produce thousands ofseeds. Tomatoes produce perfect, self-pol-linating flowers (Fig. 45). Anthers are fusedtogether into a little cone that rarely opens

Fig. 45. Tomato flower cluster

until pollen has been shed and the stigmapollinated. Older varieties may have stig-mas that stick out beyond the anther cone.Purity may be ensured by separating variet-ies with short styles (most modern varieties)by at least 3 m. Varieties with long styles(heirlooms and some cherries) need at least30 m to ensure purity. If solitary bees areprevalent, separate all varieties at least 30m and place another flowering crop in be-tween. Alternatively, bagging the wholeflower cluster can prevent cross-pollination.

SelectionLook for early maturing and attractiveplants. Selected plants should be marked,staked, and inspected during the growingseason for resistance to diseases.

HarvestingAllow tomatoes to completely ripen on theplant before harvesting for seed (Fig. 46).Seeds from green, unripe fruits will be mostviable if extracted after allowing the fruitsto turn color, but this is not advisable.

Fig. 46. Tomatoes ready for harvesting


ProcessingCut each tomato into half at its equator,opening the cavities that contain the seeds.Gently squeeze out the jelly-like substancethat contains the seeds (Fig. 47). Place thejelly and seeds into a small container for fer-mentation; add a little water if you areprocessing only one or two small tomatoes.Loosely cover the container and place in awarm place (around 25–30 °C) for 1–2 days,stirring daily.

A layer of fungus will begin to appear onthe top of the mixture after a couple of days.

This fungus not only eats the gelatinous coatthat surrounds each seed and prevents ger-mination, it also produces antibiotics thathelp to control seed-borne diseases such asbacterial spot, canker, and speck.

After fermentation, fill the seed containerwith water. Let the contents settle and be-gin pouring out the water along with piecesof tomato pulp and immature seeds floatingon top. Viable seeds are heavier and willsettle to the bottom of the container. Repeatthis process until water being poured out isalmost clear and clean seeds line the bot-tom of the container (Fig. 48). Pour theseclean seeds into a fine-mesh strainer. Let theexcess water drip out and invert the straineronto paper towel, fine mesh, or newspaper.Allow the seeds to dry completely in an oven(Fig. 49) or in partial shade (Fig. 50). Breakup the clumps into individual seeds, labeland store for later use.

Fig. 47. Extracting seeds by hand

Fig. 48. Rinsing seeds

Fig. 49. Preparing seeds for drying in an oven

Fig. 50. Drying seeds in partial shade


ProductionYardlong bean (Vigna unguiculata ssp.sesquipedalis) grows best under warm tem-peratures (25–35 °C) and full sunlight. Mostvarieties are day-neutral plants that flowerall year-round.

IsolationYardlong bean produces perfect, self-polli-nating flowers. Cross-pollination by insectsis possible but rare as self-pollination oc-curs before the flower opens (the openinganthers push up against the stigma). Isola-tion is not necessary.

SelectionAt an early stage when pod color and desir-able characters can be easily seen, selectthose healthy plants and mark them for seedproduction. Rogue out diseased plants.

HarvestingAllow pods to dry brown before harvesting.The first harvest will be 8–10 weeks aftersowing, followed by 2–3 harvests per weekduring the 6–8 week season. Cut pods witha sharp knife to minimize plant damage.Pods that are harvested 20 days after polli-nation will give the maximum seed quality.

ProcessingPods are dried in the sun for approximately3 days (Fig. 52). For small amounts, podsmay be opened by hand. For large amounts,hang the pods in a burlap bag and beat themwith a stick, or put on the floor and walk onthem. Remove large chaff by hand or win-nowing. Discard blemished and shriveledseeds. Place remaining seeds under shadefor 1–2 weeks for further drying.

YYYYY ardlong beanardlong beanardlong beanardlong beanardlong bean

Fig. 51. Yardlong bean podsFig. 52. Yardlong bean pods hung in bundlesfor drying


Ashworth, S. 1991. Seed to seed. Seed Sav-ers Exchange, Inc. Seed SaverPublications, Decorah, Iowa.

AVRDC. 2004. Seed production and pro-cessing in indigenous vegetables. pp.29–31. In: AVRDC Report 2003.AVRDC – The World Vegetable Center,Shanhua, Taiwan.

Berke, T.G. 2000. Multiplying seed of pep-per lines. AVRDC InternationalCooperators’ Guide. Asian VegetableResearch and Development Center,Shanhua, Taiwan.

Chen, N.C. 2001. Eggplant seed production.AVRDC International Cooperators’Guide. Asian Vegetable Research andDevelopment Center, Shanhua, Taiwan.

Fanton, M. and J. 1993. The seed savers’handbook. The Seed Savers’ Network,Byron Bay, Australia.

George, R.A.T. 1985. Vegetable seed pro-duction. Longman Press, Essex.

International Seed Saving Institute. 2002–2003. Saving seeds, seed-savingeducation and permaculture. <http://www.seedsave.org/issi/issi.html>

Kelly, A.F. and R.A.T. George. 1998.Encyclopaedia of seed production ofworld crops. John Wiley & Sons, NewYork.

Lal, G. D. Kim, S. Shanmugasundaram, andT. Kalb. 2001. Suggested cultural prac-tices for mungbean. AVRDC TrainingGuide. Asian Vegetable Research andDevelopment Center, Shanhua, Taiwan.

Opeña, R.T., J.T. Chen, T. Kalb and P.Hanson. 2001. Seed production of open-pollinated tomato lines. AVRDC

RRRRR eferenceseferenceseferenceseferenceseferences

International Cooperators’ Guide. AsianVegetable Research and DevelopmentCenter, Shanhua, Taiwan.

Palada, M.C. and L.C. Chang. 2003. Sug-gesting cultural practices for bitter gourd.AVRDC International Cooperators’Guide. Asian Vegetable Research andDevelopment Center, Shanhua, Taiwan.

Palada, M.C. and L.C. Chang. 2003. Sug-gesting cultural practices for vegetableamaranth. AVRDC International Coop-erators’ Guide. Asian VegetableResearch and Development Center,Shanhua, Taiwan.

Rashid, M.A. and D.P. Singh. 2000. Amanual of seed production inBangladesh. AVRDC-USAID-Bangladesh Project. Joydebpur, Gazipur,Bangladesh.

Simon, P.W. 2005. Carrot seed production.United States Department of Agriculture,Agricultural Research Services, Wash-ington D.C.. <http://www.ars. usda.gov/Research/docs.htm?docid =5235>. Ac-cessed December 2005.

Sukprakarn, S 1993. Kangkong seed pro-duction. In: Vegetable seed production.Department of Agricultural Extension,Thailand.

Sukprakarn, S. 1993. Lettuce seed produc-tion. In: Vegetable seed production.Department of Agricultural Extension,Thailand.

Turner, C.B. 1998. Seed sowing and sav-ing. Storey Communications, Inc.,Pownal, Vermont.

saving your own vegetable seeds: a guide for farmers

Education

cucumber family cucumber

beet family beet

ownvegetable seedsa

sunanta juntakool

regional centerp

malabar spinach

asian development bank

sutevee sukprakarn