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A Farmer's Guide To Saving Vegetable Seeds

A Farmer's Guide To Saving Vegetable Seeds



A Farmer's Guide To Saving Vegetable Seeds

A Farmer's Guide To Saving Vegetable Seeds



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    A Farmer's Guide To Saving Vegetable Seeds A Farmer's Guide To Saving Vegetable Seeds Document Transcript

    • Saving Your Own Vegetable Seeds A Guide for FarmersWritten by: Sutevee Sukprakarn, Sunanta Juntakool and Rukui Huang Kasetsart University Tom Kalb AVRDC—The World Vegetable CenterWith support from The Asian Development Bank
    • AVRDC—The World Vegetable Center is an international not-for- profit organization committed to alleviating poverty and malnutrition through research, development, and training.AVRDC—The World Vegetable CenterP.O. Box 42, Shanhua, Tainan, Taiwan 74199, ROCtel: +886-6-583-7801fax: +886-6-583-0009e-mail: avrdcbox@avrdc.orgweb: www.avrdc.orgAVRDC—Asian Regional CenterP.O. Box 9-1010 , Bangkok 10903,Thailandtel: +66-2-942-8686, -8687fax: +66-2-942-8688e-mail: arc_wvc@ksc.th.comweb: www.arc-avrdc.org© 2005 AVRDC—The World Vegetable CenterISBN 92-9058-144-1Edited by Tom KalbCover design by Ming-che ChenCitationSukprakarn, 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.
    • C ontentsAcknowledgments .......................................................................................... iiForeword ....................................................................................................... iiiOverview of seed saving ............................................................................... 1Amaranth ....................................................................................................... 4Bean ............................................................................................................... 5Beet family (beet, spinach and Swiss chard) ................................................. 6Brassicas (broccoli, Brussels sprouts, cabbage, cauliflower, Chinese cabbage, kohlrabi, mustard and turnip) .................................................... 7Carrot ............................................................................................................. 8Cucumber family (cucumber, melon, pumpkin, squash and gourd) .............. 9Eggplant ......................................................................................................... 11Jute ................................................................................................................. 12Kangkong ....................................................................................................... 13Lettuce ........................................................................................................... 14Malabar spinach ............................................................................................ 15Mungbean ..................................................................................................... 16Okra .............................................................................................................. 17Onion ............................................................................................................ 18Pepper ........................................................................................................... 19Radish ........................................................................................................... 20Soybean ......................................................................................................... 21Tomato .......................................................................................................... 22Yardlong bean ............................................................................................... 24References ..................................................................................................... 25 Saving Your Own Vegetable Seeds | i
    • A cknowledgmentsMany 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.ii | Saving Your Own Vegetable Seeds
    • F orewordGood 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, F1hybrid 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 | iii
    • O verview of seed savingWhich seeds can be saved? properly. The seed saving techniques of many common vegetables will be introducedVegetable seeds can be saved to sow new in this manual.crops in the future, but not all seeds are suit-able for saving. Varieties suitable for seed Before you start to save seeds, it is nec-saving include local varieties that have been essary to know a few things about thegrown in one region for a very long time, reproductive ability of plants. Many veg-self-pollinating crops (for example, beans etable species produce flowers with the maleand peas), and open-pollinated varieties of part (anther) and the female part (stigma) insome cross-pollinating crops (for example, the same flower. These are called perfectpepper, cucumber and carrot). flowers (Fig. 1). However, in maize and most varieties of the cucurbit family (cucum- Commercial F1 hybrid varieties are popu- bers, melons, pumpkins, etc.), the antherslar among many vegetable growers today. and the stigma are in the same plant but onHowever, the seed of hybrid fruits should different flowers. These are called imper-not be saved, because the F1 hybrid seeds fect flowers (Fig. 2).were produced by crossing two different par-ent varieties. Seed saved from hybrids will Pollination occurs in plants when polleneither be sterile or the plants of the next gen- from the anthers of the flower is depositederation may show wide variation in on the stigma. In some perfect flowers, self-characters, uniformity and maturity. pollination occurs. Lettuce, tomato, and okra have the stigma so close to the anthers such Seed saving involves selecting suitable that the slightest wind movement can causeplants from which to save seeds, harvesting the pollen to drop onto the stigma withinseeds at the right time, and storing them the same flower. In peas and beans, self-pol-Fig. 1. Perfect flower of eggplant: the stigma Fig. 2. Imperfect flowers of squash: female(green) is surrounded by anthers (yellow) flower with exposed stigma (left) and male flower with exposed anthers (right) Saving Your Own Vegetable Seeds | 1
    • lination occurs even before the flower opens. Bagging. When only a small amount of seed is needed, cover the unopened flowers Other types of perfect flowers require with a paper bag. This is applicable for cropscross-pollination. An external pollinator with a high but not 100% rate of self-polli-such as an insect is necessary. Onion, car- nation, such as pepper and eggplant. Yourot, cabbage, and radish, for example, can also bag the flowers of cucurbits (Fig.belong to this type. 3); in this case, both male and female flower Plants with imperfect flowers require should be bagged, but hand-pollination iswind or insects such as bees to transmit pol- required.len from the anthers of the male flowers to Caging. Cages can be used for vegetablesthe stigma of the female flowers. Maize, for that flower over a long time or to preventexample, is cross-pollinated by wind, while insects from transmitting pollen from twocucurbits are cross-pollinated by bees. nearby varieties of the same crop (Fig. 4). You can use bamboo rods stuck in theHow to keep seeds pure? ground to make an arched tunnel and cov-Keep in mind that natural cross-pollination ered with nylon mesh. Because the cage willcan always happen to some extent under a exclude all insects, you may need to handfield situation, even in self-pollinating pollinate the plant to ensure seed set, or youplants. It often occurs when pollen grains can introduce bees into the cage if they arestick onto the bodies of insects visiting flow- cross-pollinated species.ers, and then carry the pollen grains to thenext flower they visit. What is the best way to store Isolation in distance. Pure seeds can be seeds?produced by leaving enough distance be- After saving your seeds, it is important totween two or more varieties to prevent keep them alive for future use. Newly har-cross-pollination by insect or wind-blown vested seeds should not be immediatelypollen. How far apart differs among veg- stored in a plastic bag because the moistureetables; this will be described for each content of the seed is still high and will leadvegetable in the following chapters. to deterioration.Fig. 3. Bagging bitter gourd flower for hand pol- Fig. 4. Isolation of pepper selections in nylonlination net tunnels2 | Saving Your Own Vegetable Seeds
    • 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 (seed Fig. 5. Seeds stored in air-tight containers tomoisture content around 7–8%) before stor- prevent them from absorbing moistureage, and keep them in an air-tight container,such as a screw-top jar (Fig. 5). Darkness. Exposure to sunlight will Most vegetable seeds can be safely storedshorten the life of seeds. Use dark-color jars for at least three to five years. Place seedsor nontransparent containers to protect seed in manila envelopes, cloth or mesh bags,from sunlight. If using clear jars, place them plastic containers, or foil envelopes. Thein paper bags to shield out sunlight. best containers are air-tight, such as a sealed glass jar, metal can, or foil envelope. Label Temperature. For most vegetable seeds, each container carefully. Note the names ofa temperature below 15 °C is ideal. You can the line or variety, the year, and any otherkeep the seeds in an air-tight container and information you feel is valuable. Store seedsplace the container in the refrigerator. For in a cool, dry place.short-term storage, keep the seeds in a cooland shady dry place. Saving Your Own Vegetable Seeds | 3
    • A maranthProduction HarvestingAmaranth (Amaranthus spp.) is an impor- A lightening or yellowing of foliage colortant food crop in Africa and Asia, especially is an indication that seeds are beginning tofor subsistence farmers. It is a fast-growing mature (Fig. 6). Types with an apical inflo-crop that easily grows on a wide range of rescence are usually harvested once. Typessoils and climates. The plant prefers tem- with several side shoots are harvested sev-peratures between 25 and 30 °C. eral times as the seeds mature. The harvested seed stalks are placed on a clean tarpaulin There are many Amaranthus spp. grow- or into very fine mesh nylon bags and al-ing as weeds (for example, A. spinosus) lowed to dry in the shade.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, again Fig. 6. Maturing seed stalks of amaranthremoving off-types. Once flowering begins,plants with off-type flowers should bequickly removed. Processing Seeds are easily threshed by hand. The threshed seed is cleaned by winnowing.4 | Saving Your Own Vegetable Seeds
    • B eanProductionSeed 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 plants Fig. 7. Maturing bean podsas well as plants affected by diseases.Harvesting ProcessingPods are harvested when they have turned Dry the pods in the sun and then place in ayellow but are not yet completely dry. The shelter for 1–2 weeks of curing. Pods areinner seeds will be firm, well developed, and threshed by hand, being careful not to in-beginning to loosen inside the pods. Har- jure or split the seeds (injured seeds willvesting is often done in the morning to avoid germinate without primary leaves and growlosses due to shattering. poorly). Seed is further cleaned and dried after threshing. Saving Your Own Vegetable Seeds | 5
    • B eet Family (beet, spinach and Swiss chard)Production SelectionThe beet family (Chenopodeae) includes Rogue out off-types taking into consider-beet and Swiss chard (Beta vulgaris) as well ation the shape and color of leaves and roots.as spinach (Spinacia oleracea). Plants are Plants that bolt and go to seed early shouldgrown as an annual for edible leaves and as be removed. Save seed from at least sixa biennial for seeds. The crop prefers cool plants to prevent inbreeding.weather but is widely adaptable. Seed pro-duction can be done in cooler regions of the Harvestingtropics and subtropics. Two methods are Seed does not ripen uniformly on the plantused: and sheds easily when mature. Cut stalks Seed to seed. Sow seeds in late summer. when most flowering clusters have turnedMulch in late fall to ensure winter survival. brown and stalks have turned yellow andThe following spring, select the finest young dried—the first seeds are shed at this time.plants and transplant using 45-cm spacing.The optimum transplant diameter is 2.5 cm. ProcessingThe tops may be trimmed, but not the root. Store stalks in a cool dry location for 2–3 Root-to-seed. Harvest first-year roots in weeks to encourage further seed ripening.fall. Select desirable roots and trim tops 2– Do not heap stalks on top of one another5 cm above root. Store at 4 °C in a humid since this causes seeds to ferment. Handlelocation. Replant in early spring at 45-cm stalks as little as possible since seeds shedspacing with tops just showing above soil. easily. Small quantities of seed can be stripped by hand as seed matures. Large In either method, only transplant the most numbers of stalks can be put into a bag anddesirable plants. Stalks may become tall beat with a stick. Chaff is winnowed away.(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. Fig. 8. Seed stalk of beet6 | Saving Your Own Vegetable Seeds
    • B rassicas (broccoli, Brussels sprouts, cabbage, Chinese cabbage, kohlrabi, mustard and turnip)Production of the mature head, being careful not to dam- age the growing point of the inner core. ABrassicas (Brassica spp.) are one of the most scooping slice may be done to the matureimportant vegetable groups in the world. curd of cauliflower. The tops of matureMost varieties are grown as temperate bi- Brussels sprouts plants are clipped to pro-ennial crops, but tropical annual types areavailable. Brassicas prefer a cool climate mote flowering. Other tropical brassicas willand temperature is the most important fac- readily produce flowers. Seed stalks maytor for seed production. Seed can be require staking for support.produced either by the head-to-seed methodor seed-to-seed method. The following de- Isolationscribes the latter method, which is used for All brassicas will cross with each other.tropical varieties that require little or no cold Cabbage, cauliflower, broccoli and Brusselsweather to induce flowering. sprouts cross readily with each other, as do radish, mustard, Chinese cabbage and tur- The planting time is critical. The crop nip. Cross-pollination is done by honeybeesshould be raised such that the plants face (Fig. 9) and an isolation distance of 1000 mthe coldest temperature at the time of matu-rity or head formation. A long cool season between varieties is recommended.is also needed for seed pod development.Crops are typically sown/transplanted in Selectionearly to mid-fall so that plants are heading Off-type plants can be removed at any time.in late fall, blooming in early winter, and Most growers rogue the field at the time ofdeveloping seeds through the rest of winter. head/curd maturity so they can see the size, shape and firmness of heads/curds. Special techniques may be used to facili-tate the emergence of seed stalks. Forcabbage, an “X” crosscut is made at the top Harvesting Brassica seed shatters easily. Harvesting is done carefully when 60–70% of the pods have turned brown and most of their inner seeds are light brown and firm. Processing Harvested seed stalks are cured for 1–2 weeks. Pods are then threshed with sticks and sifted by hand. Seed is brittle and should not be crushed when handled. Seed is driedFig. 9. Honeybee pollinating brassica flower in partial sun, then cleaned and stored. Saving Your Own Vegetable Seeds | 7
    • C arrotProduction different varieties 800 m apart. Remove wild carrot weeds since they will pollinate withCarrot (Daucus carota) seed production re- carrot.quires two years. Roots form during the firstyear and then require a cold period (at least10 weeks of temperatures below 15 °C) to Selectionstimulate flowering and seed production. Rogue off-types taking into considerationTwo methods of production are used: the root color and shape, plant habit, and plant vigor. Plants that bolt and go to seed Seed-to-seed. Pencil-sized or larger roots early should be removed. Save seed fromare left in the ground overwinter. In late fall, many carrots to maintain crop vigor.plants are thinned to 5 cm apart, tops arecut back to 5 cm high, and mulched. Once Harvestingtemperatures rise in spring, the mulch is re-moved and leaves will regrow. After several The seed turns brown 6 weeks after polli-weeks, a seed stalk will appear. Superior nation (Fig. 11). Before the seed shatters,plants are thinned to stand up to 75 cm apart. cut and place umbels into paper bags to dry completely. Late-season rains will reduce Root-to-seed. Harvest eating-sized roots seed quality. For small amounts, handpickfor replanting in early spring. Clip tops to 5 each umbel as it dries brown. Large amountscm and store at 4 °C in a humid location or of seed can be harvested by cutting the en-layered in sawdust or sand. Replant roots tire stalk as umbels begin to dry.75 cm apart with soil just covering shoul-ders. This method is most reliable and allows Processingfor inspection of roots for seed production. Allow seed to mature in a cool, dry location for an additional 2–3 weeks. Seeds can beIsolation removed by hand-beating or rubbing umbelsCarrot plants produce perfect flowers (Fig. between hands. Winnow to clean. Remove10) that are pollinated by insects. Separate spines from dry seed by rubbing.Fig. 10. Cluster of carrot flowers (umbel) Fig. 11. Cluster of mature seeds8 | Saving Your Own Vegetable Seeds
    • C ucumber Family (cucumber, melon, squash, pumpkin and gourd)Production time in a single location by using hand pol- linating techniques:The cucumber family (Cucurbitaceae), com-monly referred to as ‘cucurbits’, includes Hand pollination. Cap or bag female andcucumbers, melons, squashes, pumpkins, male flower buds on the same plant orand gourds. They are all warm season crops nearby plant of the same variety. Then se-and very susceptible to frost. Many cucurb- lect male flowers when they bloom, turnits are susceptible to foliar diseases that over their petals to expose their anthers, andattack plants during periods of high humid- gently roll the anthers over the stigma of theity and rainfall. Therefore, regions having just bloomed female flowers (Fig. 14); youhigh temperatures and low humidity are can see a layer of pollen has been transferredideal for the production of cucurbit seeds. on the stigma. After pollination, cap or bag the female flower again to exclude insectsIsolation (Fig. 15). Mark the pollinated female flowerMost cucurbit plants produce separate male by wrapping a string to the pedicel.and 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 Figs. 14, 15. Pollen on anther of male flower is rolled onto stigma of female flower (left) and the female flower is bagged (right) Selection Select early flowering, vigorous plants. Hand-pollinate the female flowers located 10–20 nodes from the base of the plant. Re- move any deformed fruits. Harvesting The fruits should be left to fully ripen and turn color. The fruits of luffa and bottle gourd should be left on the plant until theyFigs. 12, 13. Female (left) and male (right) flow-ers of squash dry (Fig. 16). For cucumbers, fruits will turn Saving Your Own Vegetable Seeds | 9
    • Processing For ‘wet seeds’ such as cucumber, wax gourd, bitter gourd and melons, cut the fruit lengthwise and scrape seeds out with a spoon (Fig. 18). Allow seeds and the jelly- like surrounding liquid to sit in a container at room temperature for 1–2 days (Fig. 19). Fungus may start to form on top. Stir daily. The jelly will dissolve and good seeds will sink to bottom while remaining debris and immature seeds can be rinsed away. SpreadFig. 16. Mature luffa gourd fruits seeds on a paper towel or screen until dry.brownish color (Fig. 17). Bitter gourd fruits For ‘dry seeds’ such as luffa and bottlewill turn orange. Some wax gourds will be gourd, keep the seeds in the fruit until theycovered with a pale-white powdery wax on naturally separate from the flesh. This canthe surface of the fruit. After harvest, the be identified when you shake the fruit, thefruits can be kept in a shed for a couple of sound of seeds moving inside is heard. Cutweeks to allow the seed to further ripen. off the bottom of the fruit and shake the seeds out, winnow to clean the remaining chaff, then place the seed on a screen for further drying before storage.Figs. 17–19. Wet seed extraction: mature cucumber (left), seed extraction (center), and ferment-ing seed (right)10 | Saving Your Own Vegetable Seeds
    • E ggplantProductionEggplant (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 or Fig. 20. Fruits at harvestwith another tall, flowering crop. Anotherway is to bag a few flowers from each plantto exclude insects. Tie the paper bag onto Processingthe flowers before they open and remove as The outer covering is peeled off and the fleshsoon as the fruits are set. If there is only one with the seeds is cut into thin slices (Fig.variety of eggplant being grown, isolation 21). These are then softened by soaking untilis not needed. the seeds are separated from the pulp. If the material is allowed to stand overnight in thisSelection condition, the separation of seeds from the pulp becomes easier. After separation, theSelect the most vigorous and healthy plants, seeds are dipped into water. The plump seedsmark fruits on the second branch, and leave will sink to the bottom. The seeds shouldthem until they are fully mature. Keep one then be dried on a mesh for a couple ofor two fruits from one plant and several fruits weeks in a cool, dry place before storage.from 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. Fig. 21. Mature eggplant cut into small pieces for fermentation and seed extraction Saving Your Own Vegetable Seeds | 11
    • J uteProduction ers before they open to protect them from being contaminated by pollinating insects.Native to Africa, jute (Corchorus spp.) isnow cultivated over a wide range of envi-ronments today. The adaptable plant grows Harvestingin humid to semi-arid areas throughout the Among the more than 15 species oftropics and subtropics. Jute responds espe- Corchorus, two are most common: C.cially well to warm, humid weather and is olitorius and C. capsularis. The former pro-often grown near riverbanks. Jute grows duces long capsules while the latterwell in many soil types. produces round capsules (Figs. 23, 24). Both types of capsules are harvested when fully Flowering is usually induced by short-day mature but before seeds begin to shatter.conditions; 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- Figs. 23, 24. Popular species Corchorus olitorius (top photo) and C. capsularis (bottom photo) are closely related, differing mainly in pod shape Processing Dry the capsules under shade. The seeds can later be separated from capsules easily.Fig. 22. Healthy and vigorous jute plant withseed capsules12 | Saving Your Own Vegetable Seeds
    • K angkongProduction HarvestingKangkong or water convolvulus (Ipomoea When seed pods are mature (Fig. 25), up-spp.) can be grown successfully both as a root plants when dry weather is expectedleafy vegetable crop or for seed production for several days.under tropical conditions. For seed produc-tion, kangkong prefers a long period of Processingwarm weather and good irrigation. Remove plant roots with a hoe, and keepKangkong can be planted on any type of soil, plants in the field for a few days to ensurebut prefers a slightly acidic soil as long as that all the seeds will mature at the samethere is adequate sunlight and water. Low- time. The plant mat will then curl into a looseland plantings give higher seed yields than bundle. Each day, turn the bundles severaldo upland plantings, but take 5–6 months times so they dry uniformly (Fig. 26). Afterto complete the seed cycle. 3–4 days of drying, the plants should be fully dry and ready for threshing. Use an appro-Isolation priate mechanical thresher, such as a beltKangkong is considered to be a self-polli- thresher (Fig. 27). After threshing, the seednated crop, but cross-pollination may occur. should be cleaned by winnowing.Isolate varieties 100 m apart. StorageSelection Kangkong seed will store for up to twoSelect plants that are vigorous, disease-free years, a shorter time compared to most veg-and uniform in plant characteristics. etable crops. Storage pests are a problem if seed moisture content is high.Figs. 25–27. Mature seed pods (left); rolling plants seed plants into loose bundles for drying(center); mechanical threshing of dried plants (right) Saving Your Own Vegetable Seeds | 13
    • L ettuceProduction duce poor quality lettuce for consumption. Plants for seed production may need to beLettuce (Lactuca sativa) can be grown eas- staked for support (Fig. 28).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- Harvestingvisable for seed savers to produce only leaf When two-thirds of the flowers of the stalklettuce seeds. They require warm tempera- are turning fluffy white, about 2–3 weekstures (26 °C or higher) to bolt and set seed. after flowering, the seed can be harvested from single plants by shaking their headsIsolation into a canvas bag. This can be done every 2–3 days, or you can put the whole plant onLettuce produces perfect, self-pollinating a mat under shading. The seed will continueflowers. But a small amount of natural cross- to ripen and shatter.pollination can occur—from 1–6% whentwo varieties are grown side by side. A sepa-ration of 2–3 m or the establishment of a Processingtall crop such as maize between different After completely dried with white pappis,varieties is sufficient to reduce outcrossing. seed heads are rubbed with hands to remove seeds. If necessary, separate seeds from chaffSelection by winnowing.Select the best plants at the edible stagewhen you normally harvest for consumption Storageand mark them by putting a tag into the field Lettuce seed loses its viability quicker thannear each selection. Early bolting plants are most vegetable crops. Under ideal cool andnot usually kept for seeds because the seeds dry conditions, seeds may maintain their vi-from the early bolting plants will also pro- ability for up to 3 years.Fig. 28. Staked plants Fig. 29. Shattering seeds14 | Saving Your Own Vegetable Seeds
    • M alabar spinachProduction HarvestingMalabar spinach (Basella spp.), also known Harvest mature fruits with dark purple coloras Ceylon spinach and Indian spinach, is a (Fig. 31). The vines sometimes turn brownclimbing perennial plant. The vine is suc- or yellow at this stage. Fruits may be har-culent with tender leaves. vested singly or in clusters. 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. Fig. 31. Flowers and mature fruits Processing Two methods may be used. One option is to remove the seed coats by washing with tap water, followed by drying of seeds in the sun. The alternative method is to dry the fruitsFig. 30. Malabar spinach growing on a trellis with their seed coats attached. Fruits are juicy and if drying is incomplete the seeds turn bad. Seeds are subsequently threshed,Selection cleaned by winnowing, and later dried moreSelect seed from healthy, vigorous growing completely in the sun.plants with uniform plant habit.IsolationIt appears to be a self-pollinated speciesjudging from the characteristics of its flow-ers and performance at AVRDC. Saving Your Own Vegetable Seeds | 15
    • M ungbeanProduction machine, adjust the speed of the machine in order to avoid seed damage.Mungbean (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. Fig. 32. Mature pods ready for harvestingSelectionOff-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, harvesting Fig. 33. Shattered podsmay 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 threshing16 | Saving Your Own Vegetable Seeds
    • O kraProduction before flowering, taking into consideration the vigor and habit of the plants. Once flow-Okra (Abelmoschus esculentus) can be ering begins, plants with off-type flowersgrown on a wide range of soils with good should be removed. After the first pods aredrainage, but sandy loam soils are preferred. developed, remove plants with off-typeTemperatures between 27–30 °C promote pods. Plants with viral symptoms should berapid and healthy seedling development. removed as soon as symptoms appear.Seeds will not germinate below soil tem-peratures of 17 °C. Seeds should be soakedin water for 24 hours before sowing. Plants Harvestinggrow well in raised beds (20–30 cm high). The okra pods mature in a sequence from the base of the plant toward the top (Fig.Isolation 35). The pods have tendency to split along the suture when they are dried out. ExposedOkra flowers (Fig. 34) are often cross-pol- seeds may be damaged by rain or may droplinated by insects. An isolation distance of to the ground; therefore, the pods must be500 m or more is recommended. An alter- harvested as soon as they have become fullynative method of keeping seed pure is to mature (brown color) and before shattering.bag the flower buds and hand-pollinate onceflowers have opened. ProcessingSelection Pods are easily hand threshed.Plants for seed multiplication can be selectedFig. 34. Okra pod and flower Fig. 35. Pods maturing from the base of the plant Saving Your Own Vegetable Seeds | 17
    • O nionProduction are dried, store for at least 2 weeks at 4 °C in a dry, airy location (a refrigerator is ideal).Onion, Allium cepa, is one of the most Before replanting, slice off the top one-widely cultivated vegetables in the world. fourth of the bulb to promote sprouting.Onion forms its bulb in the first year and Space bulbs 30 cm apart and cover with 2produces seed in the second year. Tempera- cm of soil.tures around 20–22 °C favor vegetativegrowth while temperatures around 12 °Cfavor seed stalk formation. Onion flower- Isolationing is sensitive to daylength—for most Isolate from other flowering varieties at leastvarieties grown in the tropics, short days are 1000 m apart. Cross-pollination is per-conducive to seed production. One bulb can formed by insects (Fig. 36). An alternativeproduce 20 or more stalks and may be in method of isolating superior plants is tobloom for over 30 days. Onion produces place cages over them and introducing pol-perfect flowers, most of which are cross- linators into the cages.pollinated. Two methods of producing seedare used: Selection Seed-to-seed. Plant seeds in summer. Im- In using the bulb-to-seed method, replantmature onions are more winter hardy than only disease-free bulbs that are true-to-type.larger, full-grown bulbs. Mulch in late fall Discard doubles or long, thick-necked bulbs.to ensure winter survival. Thin to 30-cm For bulbs preparing to flower, remove anyspacing in the spring. types of undesirable shape or color; do this Bulb-to-seed. Harvest in the fall and se- before flowering begins. Save seeds fromlect the largest bulbs (which naturally several plants to maintain crop vigor.produce more seed). Clip tops to 15 cm andcure for three to four weeks. After the bulbs Harvesting Clip umbels as soon as most flowers have dried and before seeds begin shattering. Some growers harvest when the seeds are exposed in 10% of the umbels. Processing Fully dried flowers will drop clean seeds naturally. For small amounts, rub remain- ing flowers to free seeds. For larger amounts, rub heads over screens. Winnow to remove remaining debris. Allow to dry in cool, dry location for up to 2–3 weeks. Frequently stirFig. 36. Insects pollinating onion flowers the seeds. Artificial drying is often used.18 | Saving Your Own Vegetable Seeds
    • P epperProduction SelectionPepper (Capsicum annuum) grows best in The earliest maturing and more attractivethe dry season with temperatures in the range plants should be marked and inspected dur-of 21–33 °C. The night temperature is espe- ing growth. Select healthy, attractive fruitscially critical; generally, plants will not set for seed saving. Seeds from off-type plantsfruits if night temperatures remain above or fruits should not be saved.30 °C. Ideally, select a field where the pre-vious crop was a legume or a cereal. Avoid Harvestingfields where the previous crop was sweet Harvest mature, fully-ripe peppers for seed.potato or a solanaceous crop (tomato, pep- Most peppers turn red when fully mature.per, eggplant, and white potato). Thisprevents the build-up of diseases and insects. ProcessingIsolation Pepper seeds may be extracted from fresh fruits (Fig. 37) or from fruits that have beenPeppers produce perfect, mostly self-polli- dried in the sun for a few days (Fig. 38).nating flowers. Solitary bees will pollinate Seeds may be removed by hand or extractedif other more desirable pollen is not avail- by grinding the fruits and separating theable in the area. Most growers will get seeds from fruits with a series of watersatisfactory results if different varieties are rinses. Spread the seeds on a screen for dry-separated by 20 m or with another tall, wind ing under shade for 2–3 days but bring thembreaking crop. Closing the flower bud with inside every evening.a cotton ball when the distance of isolationis not sufficient is an ideal method to pre-vent cross-pollination.Fig. 37. Sweet pepper cut for fresh seed ex- Fig. 38. Chili pepper prepared for dry seed ex-traction by hand traction Saving Your Own Vegetable Seeds | 19
    • R adishProduction bolting plants are removed. Selection is more difficult in the seed-to-seed methodRadish (Raphanus sativus) is a member of because one cannot see the entire root. Nev-the cabbage family and grown worldwide. ertheless, growers using this method shouldThe harvested roots, prized for their pun- aggressively rogue out undesirable plantsgent taste, come in a wide variety of colors, taking into consideration the same factorsshapes and sizes. There are two major types. as with the root-to-seed method.First, there are the biennials of temperateorigin that require a cold period for flower-ing. These include the Japanese, American Harvestingand European radishes. Second, there are Threshing seeds from pods are difficult.radishes of tropical origin that do not require Allow the plants to mature fully; then bringa cold period for flowering. them to the threshing floor for drying. Radish grows best in a cool dry climate. ProcessingTemperatures above 32 °C cause the stigmato drop and the pollen may fail to germi- Threshing is done by hand-beating withnate. Two methods are used to produce seed: sticks. The seed is then dried further. 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 are Figs. 39, 40. Radish roots (top) and ripeningconsidered. Hairy or forked roots and early seed pods (bottom)20 | Saving Your Own Vegetable Seeds
    • S oybeanProduction til pods are opened, or put dry pods in a bur- lap bag, place the bag on the floor, and walkSoybean (Glycine max) grows well in well- on it. Remove any foreign materials by win-drained, loamy soils. The minimum soil nowing (Figs. 43, 44). Dry in the sun fortemperature for germination is 13 °C. The 3–5 days. Collect only good seeds (free fromoptimum time for planting soybean for seed diseases, seed coat cracking, split, or imma-production is usually in the dry season (De- ture). If using a threshing machine, adjustcember) or late rainy season (August); its speed to avoid seed damage.however, please follow the recommendedcultural practices in your own country. StorageIsolation Soybean seed does not keep well in storage compared to the other legumes. The germi-Soybean is self-pollinating; cross-pollina- nation rate drops rapidly under roomtion by insects is possible, but rare. No temperature conditions, especially in theisolation is required. tropics. If cool storage is unavailable, place seed in an air-tight container and add burnedHarvesting lime (calcium oxide) at the rate of 20–30%When soybean matures, the leaves turn yel- (w/w). Keep seed at room temperature.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. Fig. 42. Threshing pods with a stickFig. 41. Pods ready for harvestingProcessingThreshing must be done as soon as the podsare dry. Beat pods with a stick (Fig. 42) un- Figs. 43, 44. Winnowing to remove chaff Saving Your Own Vegetable Seeds | 21
    • T omatoProduction until pollen has been shed and the stigma pollinated. Older varieties may have stig-Tomato (Lycopersicon esculentum) grows mas that stick out beyond the anther cone.best in the dry season under day tempera- Purity may be ensured by separating variet-tures of 21–25 °C and night temperatures ies with short styles (most modern varieties)of 15–20 °C. Vines will struggle to set fruit by at least 3 m. Varieties with long stylesif temperatures exceed 30 °C. Humidity lev- (heirlooms and some cherries) need at leastels higher than 60% at the time of fruit 30 m to ensure purity. If solitary bees arematurity will increase disease problems and prevalent, separate all varieties at least 30reduce seed yields. Seed production during m and place another flowering crop in be-the rainy season leads to poor seed quality. tween. Alternatively, bagging the wholeAvoid fields where the previous crop was flower cluster can prevent cross-pollination.tomato; this prevents the new seed crop frombeing contaminated with seeds from volun-teer tomato plants. Growing tomato after Selectionpaddy rice reduces the incidence of diseases Look for early maturing and attractiveand nematodes. Training of tomato plants plants. Selected plants should be marked,generally results in early ripening, fewer dis- staked, and inspected during the growingeases, higher yields and better seed quality. season for resistance to diseases.Isolation HarvestingIsolation of plants is usually not needed and Allow tomatoes to completely ripen on thea single plant can produce thousands of plant before harvesting for seed (Fig. 46).seeds. Tomatoes produce perfect, self-pol- Seeds from green, unripe fruits will be mostlinating flowers (Fig. 45). Anthers are fused viable if extracted after allowing the fruitstogether into a little cone that rarely opens to turn color, but this is not advisable.Fig. 45. Tomato flower cluster Fig. 46. Tomatoes ready for harvesting22 | Saving Your Own Vegetable Seeds
    • Processing This fungus not only eats the gelatinous coat that surrounds each seed and prevents ger-Cut each tomato into half at its equator, mination, it also produces antibiotics thatopening the cavities that contain the seeds. help to control seed-borne diseases such asGently squeeze out the jelly-like substance bacterial spot, canker, and speck.that contains the seeds (Fig. 47). Place thejelly and seeds into a small container for fer- After fermentation, fill the seed containermentation; add a little water if you are with water. Let the contents settle and be-processing only one or two small tomatoes. gin pouring out the water along with piecesLoosely cover the container and place in a of tomato pulp and immature seeds floatingwarm place (around 25–30 °C) for 1–2 days, on top. Viable seeds are heavier and willstirring daily. settle to the bottom of the container. Repeat A layer of fungus will begin to appear on this process until water being poured out isthe top of the mixture after a couple of days. almost clear and clean seeds line the bot- tom of the container (Fig. 48). Pour these clean seeds into a fine-mesh strainer. Let the excess water drip out and invert the strainer onto paper towel, fine mesh, or newspaper. Allow the seeds to dry completely in an oven (Fig. 49) or in partial shade (Fig. 50). Break up the clumps into individual seeds, label and store for later use.Fig. 47. Extracting seeds by hand Fig. 49. Preparing seeds for drying in an ovenFig. 48. Rinsing seeds Fig. 50. Drying seeds in partial shade Saving Your Own Vegetable Seeds | 23
    • Y ardlong beanProduction SelectionYardlong bean (Vigna unguiculata ssp. At an early stage when pod color and desir-sesquipedalis) grows best under warm tem- able characters can be easily seen, selectperatures (25–35 °C) and full sunlight. Most those healthy plants and mark them for seedvarieties are day-neutral plants that flower production. Rogue out diseased plants.all year-round. HarvestingIsolation Allow pods to dry brown before harvesting.Yardlong bean produces perfect, self-polli- The first harvest will be 8–10 weeks afternating flowers. Cross-pollination by insects sowing, followed by 2–3 harvests per weekis possible but rare as self-pollination oc- during the 6–8 week season. Cut pods withcurs before the flower opens (the opening a sharp knife to minimize plant damage.anthers push up against the stigma). Isola- Pods that are harvested 20 days after polli-tion is not necessary. nation will give the maximum seed quality. Processing Pods are dried in the sun for approximately 3 days (Fig. 52). For small amounts, pods may be opened by hand. For large amounts, hang the pods in a burlap bag and beat them with a stick, or put on the floor and walk on them. Remove large chaff by hand or win- nowing. Discard blemished and shriveled seeds. Place remaining seeds under shade for 1–2 weeks for further drying.Fig. 51. Yardlong bean pods Fig. 52. Yardlong bean pods hung in bundles for drying24 | Saving Your Own Vegetable Seeds
    • R eferencesAshworth, S. 1991. Seed to seed. Seed Sav- International Cooperators’ Guide. Asian ers Exchange, Inc. Seed Saver Vegetable Research and Development Publications, Decorah, Iowa. Center, Shanhua, Taiwan.AVRDC. 2004. Seed production and pro- Palada, M.C. and L.C. Chang. 2003. Sug- cessing in indigenous vegetables. pp. gesting cultural practices for bitter gourd. 29–31. In: AVRDC Report 2003. AVRDC International Cooperators’ AVRDC – The World Vegetable Center, Guide. Asian Vegetable Research and Shanhua, Taiwan. Development Center, Shanhua, Taiwan.Berke, T.G. 2000. Multiplying seed of pep- Palada, M.C. and L.C. Chang. 2003. Sug- per lines. AVRDC International gesting cultural practices for vegetable Cooperators’ Guide. Asian Vegetable amaranth. AVRDC International Coop- Research and Development Center, erators’ Guide. Asian Vegetable Shanhua, Taiwan. Research and Development Center,Chen, N.C. 2001. Eggplant seed production. Shanhua, Taiwan. AVRDC International Cooperators’ Rashid, M.A. and D.P. Singh. 2000. A Guide. Asian Vegetable Research and manual of seed production in Development Center, Shanhua, Taiwan. Bangladesh. AVRDC-USAID-Fanton, M. and J. 1993. The seed savers’ Bangladesh Project. Joydebpur, Gazipur, handbook. The Seed Savers’ Network, Bangladesh. Byron Bay, Australia. Simon, P.W. 2005. Carrot seed production.George, R.A.T. 1985. Vegetable seed pro- United States Department of Agriculture, duction. Longman Press, Essex. Agricultural Research Services, Wash- ington D.C.. <http://www.ars. usda.gov/International Seed Saving Institute. 2002– Research/docs.htm?docid =5235>. Ac- 2003. Saving seeds, seed-saving cessed December 2005. education and permaculture. <http:// www.seedsave.org/issi/issi.html> Sukprakarn, S 1993. Kangkong seed pro- duction. In: Vegetable seed production.Kelly, A.F. and R.A.T. George. 1998. Department of Agricultural Extension, Encyclopaedia of seed production of Thailand. world crops. John Wiley & Sons, New York. Sukprakarn, S. 1993. Lettuce seed produc- tion. In: Vegetable seed production.Lal, G. D. Kim, S. Shanmugasundaram, and Department of Agricultural Extension, T. Kalb. 2001. Suggested cultural prac- Thailand. tices for mungbean. AVRDC Training Guide. Asian Vegetable Research and Turner, C.B. 1998. Seed sowing and sav- Development Center, Shanhua, Taiwan. ing. Storey Communications, Inc., Pownal, Vermont.Opeña, R.T., J.T. Chen, T. Kalb and P. Hanson. 2001. Seed production of open- pollinated tomato lines. AVRDC Saving Your Own Vegetable Seeds | 25
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