Hand Book Of Hybrid tomato Seed Production (A GUIDE TO SEED GROWERS AND PRODUCTION SUPERVISORS)
By RAKESH C MATHAD MSc-Agri (seed science and technology) 2008
PREFACE India is the second largest producer of vegetables, with estimated 135 MT from 6.5 MHa of land. This huge production can be achieved with the use of improved seed and technology. India is having unique distinction of being a major seed production hub of Asia. With the exception of some brassica seeds most of vegetable seeds produced in India. In Karnataka some of the places like Ranebennur, Koppal, Sira etc are producing seeds for more than 100 companies. The annual payment turnover is alone pegged at 150 crores in Ranebennur and neighboring areas. The main reasons are the climate, irrigation facilities, skilled labor and small land holdings make these areas favored destinations for seed production. Presently in India Tomato is one of important vegetable grown on an area of 4.85 lakh ha and 1.53 lakh ha (31 %) under improved varieties or hybrids. Tomato seed production (TSP) offer not only livelihood but also bring more returns on a small landholding. With just 10-20 guntas (half an acre) the B:C ratio is > 2.13. The TSP mainly in Karnataka mainly in Haveri District. In India about 40 tonnes of tomato sold every year of which 10 tonnes exported. The main aim of this book is to explain various aspects of seed production and post harvest management. I tried to use my experience and my academic learning to give a shape to this handbook. This book is aimed at seed supervisors, seed organizers, students and seed growers. Being first such effort, there could be some shortcomings for which valuable and informative suggestions will be gratefully appreciated.
Rakesh C Mathad Author
1.1 Floral Morphology: Tomato is self pollinated crop, with the bisexual flower coalesced. The stamens are elongated forming a cone enclosing the pistil and stigma. Base of the anthers are connected with bottom part of petals, thus facilitating emasculation. Isolation is not a problem but still 15 meters is advisable for commercial seed production. Fruit shapes vary with varieties (Legend-1) like oblate, globe, plum, square, pear etc. Seed per fruit varies with the shape of fruit though not a rule. 1.2 Season: Tomato seed production can be taken in May-June and Nov-Dec. In Ranebennur and other area tomato transplanted in Rabi or winter season. And crop should be closed by Jan-15th (on Makara Sankranti).
1.3 Male and Female Ratio: 1:5 or 1:3 depending upon the quantity of pollen in male flowers. 1.4 Staggering: sowing of male in nursery to be done 8-10 days before that to sowing the female.
1.5 Spacing: 60 inches between two beds and 15 inches between plants & rows within the bed. 1.6 Nursery: Seeds are sown in seed trays which are placed above the raised seed bed. Seed are sown in sterile coco-peat (a byproduct of coconut). Tomato seeds take 6-7 days to germinate and 20-22 days old seedlings are ready for transplanting. In nursery the seedlings should be taken care both nutrient wise as well as disease point. The nutrients mainly DAP @ 250 gms/100 trays (trays of 96 holes)+SSP @ 1 kg/100 trays applied with use of a rose can once in 10 days ( Twice in the 20 days period). It is better not apply any nitrogen (especially in the form of Urea which make seedlings more
succulent. Fertilizer drenching is done in the morning and water should be applied immediately to avoid burning. Foliar sprays like Nitrophoska @ 25gms per tank is also useful. For disease control following chemicals can be applied: Captan @ 1 gm / litre /25 trays, Confidor+kavach @ 10 ml / tank, Antrcol @ 25 gm +Nuvan @ 5 ml /tank/ 25 trays can be sprayed. Since nursery is done inside a insect proof net or green house disinfection with Endosulfon @ 50 ml+ Ridomil MZ @ 5 gm/Litre help to control insect or soil borne fungi. 1.7 Transplanting: The 20-22 days old seedlings will be transplanted on the raised seed beds formed in the main field. Evening is the best time for transplanting. Treating seed lings with Trichoderma at the time of transplanting helps in controlling root rot. Usually 750 male and 2000-2200 female plants are transplanted in an area of 10-15 guntas.
1.8 Staking and pruning: Depending upon the plant type 2-3 shoots maintained. It is better to leave only 2 main shoots to avoid self fruit problem in later crop cycle. Lower leaves should be pruned off to avoid contact with the soil. All the shoots are tied to a stake (wooden pole) or to metallic wire running parallel above the rows. 1.9 Pollination or crossing: In tomato crossing will be done at 45-55 DAS or 2535 DAT. The pollination duration varies with varieties from 10 to 35 days. In some varieties after some days not fruit set take place and fruiting seizes naturally. In crossing dusting of pollen on the emasculated flower buds done in the morning 8 am to 1 or 2 p.m, After pollination one can remove 3 or 4 sepals just to mark as crossed bud. This will help in harvesting of crossed buds and preventing mixing of Selfed fruits. For pollination one can use pollen ring or glass pollen tube.
Collection of male flower and pollen: Pluck the male bud which is likely
to open on next day, take out anthers, dry in partial shade for 4 hours. Collect the pollen from anthers manually using a maslin cloth between 2 cups or use occillary vibrating machine. Collect the pollen and store in plastic containers in cool place or in a refrigerator at 4 C. Use pollen rings to dust the pollen on stigma of female flowers. 1.11
Emasculation: sterilize the forceps or tweezers & hands with alcohol and
milk. Repeat this procedure after working on every 20 plants. Select only such buds which are well developed likely to open next day but the corolla is in creamy white color. With the help of forcep take out the stamen by leaving petals intact with the bud. One can emasculate 5-7 buds per cluster and can work 6-8 cluster per plant. Emasculation should be started from 2 nd cluster. Emasculation is done after pollination between 1 to 5 p.m. the emasculated buds are ready for pollination by 24 hours which is characterized by petals wide open, turns yellow which is an indication of stigma receptivity. 1.12
Harvesting: maturation of fruits starts at 20-30 after pollination and
harvesting can be done after 50-60 DAP. While picking the fruits one should check the fruit is uniformly red from all sides and also look for the mark of pollination (2-3 sepals). Such fruits are kept overnight and crushed without using water. 1.13
Fermentation and washing: The crushed fruit along with pulp and juice
kept for fermentation for 24 hours. This will help to wash seed off the pulp easily and also kill seed borne pathogen like bacterial canker. The seed and pulp after fermentation get separated.
The seed now washed in running water and dried by spreading a thin layer of mesh for one day in shade and 2 days in mild sunlight during early morning and late evening for 3 times each (Figure 1). Min. moisture to maintain is 6%. Always use clean water for washing. Do not expose seeds to direct sunlight since it will affect germination.
Figure 1 Above the ground drying on mesh
Yield: Depending upon the plant type yield may vary from 3-12 grams per
plant. The average seed yield parameters are as follows: Average Fruits / plant 15 to 30
Average Seeds / fruit 80-150
Seed yield / plant-gms 3-12
Yield Estimation/plant: (in gms): No. of Fruits per plant X No of seeds per fruit No of seeds in gm of seed Yield Estimation/plot: (in kgs): Seed Yield per plant (in gms) X No of plts per plot 1000
After care: After seed washing and drying seeds to be cleaned manually
and using screen to remove chaffy material, light seed and black seed. (Figure-2 and 3)
Figure 2 Seed cleaning using screen
Figure 3 Hand cleaning of seeds
Wet Seed Treatment: after cleaning the seed wet treatment with Tri
Sodium Phosphate (TSP) 10 % ( for 2 Hr)-Rinse-wash-Calcium Hypochlorite 0.96% (for 15 min)-Rinse-wash-Dry is done to avoid any seed borne pathogen. TSP treatment is effective against virus and Ca-Hypochlorite against Bacteria. Seed is then washed with clean water ( Figure-4 & 5)
Figure 4 Rinsing of seed in TSP and Ca-Hypochlorite
WASHING MACHINE TO REMOVE EXCESS WATER
Figure 5 Wet Seed Treatment Assembly
Purity Management in Seed Production: Purity mainly refers to genetic
purity and quality refers to germination. Genetic purity of a seed lot may get decreased when 1) there are off types present in male and female lines 2)due to imperfect emasculation or emasculation of matured buds (late emasculation) 3) presence of un-crossed or Selfed fruits and 4) mechanical admixtures due to improper storage. Off types in male and female lines can be removed by roguing which should begin at nursery level. Roguing at nursery level has to be done based on the foliage colour and stem colour. After transplanting after first fruit set-check each and every plant in both male and female lines for offtypes (Figure-6, 6a & 6b). Check for foliage colour, foliage shape (bushy plants), canopy , plant height, fruit shoulder colour and shape, for fruit peduncle jointed or joint less, zippered fruits etc.
Figure 6 Roguing Operation Tru To Type Plants Bushy Plants
The selection of bud for emasculation is another area where care has to be taken. The correct stage of bud selection is silver colour which is an indication of optimum receptivity of the stigma. Mechanical admixtures are an aspect which should be avoided by: 1. No grower should have two hybrid seed production plots of same crop in the same window. Allot plot with min. interval of 45 days. 2. The place of seed extraction, washing and drying should be poles apart. 3. After the seed is extracted, washed and dried it should be stored clearely mentioning the hybrid code and other details both inside and outside (Figure 7a & 7b)
Quality Management in Seed Production: Quality with respect to
germination is very important since there is possibility of decreasing germination due to following factors and one should take care to avoid these factors. •
Keeping the seed submerged for more time in the water. Seed should not be kept submerged for >1 hour.
Drying the seed in thick layers.
Crushing the semi-ripen or green fruits while seed extraction.
Direct exposure of seed to strong sunlight.
Storage of seed with high moisture (>8.0%)
Not retaining good nutrient practices till maturation.
Keeping the fruits in heap or covered with polythene sheets.
Using dirty water for washing.
Crushing diseased, bird effected or fruits affected with nutrient disorder (e.g.: Ca deficiency) fruits while seed extraction.(Figure 8a, 8b & 8c).
Fertilizer Management: Some of the fertilizer recommendations (in Kgs)
25 days after transplanting:20 kgs of N, 15 kgs of K (apply as ring )
45 days after transplanting:15 kgs of N, 15 kgs of K
A week after crossing:
30 kgs of N, 100 kgs of P and 60 kgs of K
16 kgs of N, 10 kgs K
Also foliar sprays like Multi-K or Nitrophoska at 10 days interval help in maintaining good canopy and thereby more photosynthesis and seed filling. 1.20
Water Management: In case of tomato seedlings should be transplanted
on the seed bed (120 cm) with irrigation channels (30 cm deep) in between. Do not allow water logging. Irrigation should be given with regular intervals once in 3-4 days till its maturation. Seedlings should be planted on irrigated surface and later make seed beds as mentioned above.
Disease and pest management: In seed production never start spraying
chemicals when disease and pests occurs. Make a prophylactic spray schedule and spray accordingly anticipating the pest and disease infestation. One e.g. of spray schedule is as follows: Stage of Application Nursery Bed
Chemical and Dosage •
Add 100 gms Thimet 10G
Drench the bed with Captan @ 3gms/bed
After Sowing drench seedlings with Carbendazim 50%WP @ 2gms/lt
• To contol soil borne insects spray Carbaryl @ 2gms/lt Spray with Cu-oxy chloride 50% WP @ 2gms/lt or Hostathion
True Leaf Stage 5 DAT 12 DAT 18 DAT 25 DAT 32 DAT 40 DAT 50 DAT
@ 2 ml/lt Dip seedlings in Monocrotophos 36% EC @ 1.5 ml/lt Spray Mancozeb 75% WP @ 2g/lt+Carbaryl @ 2g/lt Spray Chlorothalanil 50%WP @ 2gm+Imida17.8%SL @ 0.5m/ Spray Cu-oxy chloride 50% WP @ 4g+Phosalane @ 2ml/lt Spray Imida17.8%SL @ 0.5ml+hexaconozole @ 0.5 ml/lt Spray Quinolphos @ 3ml/lt Spray Acephate @ 1.5g+Mancozeb & Carbandenzim 3g/lt Spray Streptocycline @ 2g+Cypermithrin10 EC @ 1ml+Neem
60 DAT 60 DAT
based insecticide @ 3ml/lt Spray Triadimelon @ 1g+KNOL3 @1.5 g/lt Spray Triazophos+ Deltamethrin @1.5 ml/lt
Some of Common Diseases and Pests of Tomato:
Pests / Diseases Pests: Thrips/Aphids/
Contol Spray Imida17.8%SL @ 0.5ml/lt / Acephate 75% WP /
Whitefly Leaf Miner Mites Fruit Borer
Monocrotophos 36% EC Profenophos 40%+Cypermethrin 4%EC @ 1ml/lt Abamectin 1.9 % EC @ 0.5 ml/lt / Sulfer 80% WP @ 2gm/lt Spray Quinolphos 25% EC+Cypermithrin10 EC @ 1ml+Neem based insecticide @ 3ml/lt
Diseases: Damping off Early Blight Late Blight Powdery Mildew Fusarium Wilt
Drenching with Carbandenzim 3g/lt Spray Mancozeb & Carbandenzim 3g/lt / Chlorothalanil 50%WP @ 2gm Spray Metalaxyl 8%+ Mancozeb 64%WP @ 2 gm /lt Dinocap 48%EC 1ml or Triademefon 25% WP @ 0.3gm/Lt Spray Cu-oxy chloride 50% WP or Fosetyl AL 80% + Carbandenzim 1g each /lt.