Quality seed production in maize hybrids

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Transcript of Quality seed production in maize hybrids

  • 1. Introduction The hybrid seeds are produced bycrossing female and male lines and harvestingthe seeds from female line. Maize hybrid seedproduction there is no male sterility system infemale plants.
  • 2. Suitable climate In Tamil Nadu, maize is cultivated during June July, September October and January February seasons. Sowing during November - December is suitable for seed production, since seed maturity stage will not coincide with rainfall.
  • 3. Isolation distance For this isolate the hybrid seed crop from fields of other maize varieties with same seed color by 200 m distance.
  • 4. Land requirement Well drained sandy red or black soil is suitable. The selected fields should be free from volunteer maize plants.
  • 5. Field preparation. Plough the field five to six times to get fine tilt. Spread 12.5 tons of FYM or composted coir pith and 10 packets of Azospirillum in the field. Prepare ridges and furrows with 60 cm spacing.
  • 6. Sowing operation Seed rate Female -5kg/ha Male-2 kg/ha Treat the seeds with Azospirillum.
  • 7. Seed treatment To control the fungal disease treat the seed with thiram at 2g kg-1 seed. One day after treat the seeds with 600 g of Azospirillum with rice gruel and shade dry for 15 minutes.
  • 8. Sowing Ridges and furrows at 60 cm spacing is to be formed. 2 seeds per hill on the sides of ridges adopting a spacing of 25 cm between the plant is sown. During sowing, a planting ratio of 4 female lines and 2 male lines (4:2) should be followed. Four female line rows should alternate with two male rows.
  • 9. Irrigation Up to 30 days, less irrigation is given. Then it is necessary to irrigate once in 10 days. Smooth silk will emerge out from the cob after fertilization.
  • 10. Fertilizer application Apply 25 tonnes of FYM per ha. Then apply inorganic fertilizers at 100 kg N, 100 kg P and 50 kg K per ha as basal dose. On 20th and 40th day after sowing, apply 50 kg N and 25 kg P as top dressing.
  • 11. Micronutrient deficiency Zn and Mg deficiency occurs - leaves. Apply ZnSO4 @ 20 kg ha-1 as basal fertilizer. Apply micronutrient mixture @ 62.5 ha-1 mixed with 40 kg sand, after sowing the seeds.
  • 12. Weed management Two hand weeding on 25 days and 45 days after sowing. After weeding, apply fertilizers as top dressing and do the earthing up operation. Herbicides can also be applied. Spraying of Atrazin 500 g mixed in 1000 lit water and life irrigation on third day control the weeds. Roguing
  • 14. Insect ControlShoot fly - 2ml of endosulphan in 1l ofH2O.Stem Borer - carbofuran granules @ 7.5kg per acre @ 2 granules per plant
  • 15. Shoot fly Stem borer
  • 16. Disease ControlDowny Mildew: Metalaxyl 72 WP @ 1 kg ha-1, or Mancozeb 1 kg ha-1 20 days after sowing.Leaf Spot: Spray Mancozeb or Captan 1 kg ha-1
  • 17. Downy mildew Leaf spot
  • 18. Cob female inflorescence Tassel male inflorescence
  • 19. DETASSELLINGRemoval of tassels from female plants immediately afteremergence
  • 20. HARVEST Judge the optimum harvest stage Male lines Harvested first Female lines Next Hybrid seed seeds from the female line.
  • 21. COB SORTING To maintain genetic purity Remove very small sized seeds Cobs Difference in seed rows, seed number and colour. Cobs very less seeds
  • 22. SHELLING Separation of seeds from the cob Moisture content * seed 15% * cob 25% Mechanical damage 18%
  • 23. SEED DRYING Reducing the moisture content To retain their viability Moisture content 7% Temperature 40 C Avoid - Drying under hot sun
  • 24. SEED GRADING To maintain the quality from one season to the next * Other crop seeds * Weed seeds (especially herbicide resistant weeds) * Straw, soil dust and other inert material. * Immature, shriveled, damaged, cracked, under sized or oversized seed Yield = 1500 Kg /ha
  • 25. SEED STORAGE Captan 75% Wettable powder @ 70 g per 100 kg seeds mixed in 500 ml water. Package - Cloth bag or Vapour proof polyethylene bag. Storage 1 to 1 years.
  • 26. SEED CERTIFICATION Genetic purity: Seed gives rise to a plant of the same varietal characteristics Physical purity: Seed Is free from stones, broken seeds, straw bits and leaf bits etc., Physiological purity: Germination and vigour
  • 27. Contd., Authenticated source Isolation distance Inspection Seed samples Certification tag - Blue
  • 28. FIELD STANDARDS FACTOR MAXIMUM PERMITTED (%)Off types (%) maximum 0.5%Shedding tassel (%) maximum 1.0%
  • 29. SEED STANDARDSFACTOR MAXIMUM PERMITTED (%)Physical purity 98%Inert matter 2%Other crop seeds 10/KgGermination (minimum) 90%Moisture 12%For moisture vapour perviousFor moisture vapour proof containers 8%