Seed Production In Major Cereal Crops (Wheat, Rice & Sorghum) PDF

EXERCISE – 4 SEED PRODUCTION IN MAJOR CEREAL CROPS (WHEAT, RICE & SORGHUM) 1. WH EAT SINGLE PANICLE SINGLE PANICLE OF GREEN WHEAT OF DRY WHEAT SEEDS OF DRY WHEAT  1. WHEAT 1. Selection of seed plot: (weed free,...

EXERCISE – 4 SEED PRODUCTION IN MAJOR CEREAL CROPS (WHEAT, RICE & SORGHUM) 1. WH EAT SINGLE PANICLE SINGLE PANICLE OF GREEN WHEAT OF DRY WHEAT SEEDS OF DRY WHEAT  1. WHEAT 1. Selection of seed plot: (weed free, well drained, leveled plot) 2. Isolation distance: ( 3 m, loose smut – 180 m) between seed field and other field of wheat is recommended. 3. Planting time and seed rate: Timely sown (late maturing) : 15-25th Nov. Late sown (early) : 5th -15th Dece. Spacing : 22.5 cm (5 cm depth) Seed rate : 100-120 kg/ha 4.Cultural practices : (i) Fertilizer (80:60:40) NKP/ha Split N – Basal 50% (40kg) at the time of sowing and 50% (40kg) nitrogen at the crown root initiation stage i.e. after 30-35 days. 60 kg phosphorous and 40 kg potash per hectare apply at the time of sowing. (ii) Irrigation : At the time of sowing then 1st at 30-35 days 2nd - Late tillering stage 3rd - Panicle emergence stage 4th - Flowering stage 5th - Milk stage 6th - Dough stage (iii) Interculturing and weeding: 2-4 D (0.5 kg a.i. / ha) Pendimethalin (1 kg a.i. /ha) in 750 litres of water should also be used for effective control of (iv) Plant protection: Termites: Chlorpyriphos 20 EC @ 2.3 litres/ha with irrigation Stem borer : Carbofuran 3 G @ 25 kg/ha Endosulfan 35 EC @ 1.5 l/ha Loose smut : Seed treatment with systemic fungicide 5. Roguing: 1st at time of heading (off type and loose smut infected) 2nd at after flowering (remove late flowering types) 3rd at time of maturity based on ear head traits Colour of awns and ear head types as well as volunteer plants and weed plants should be removed. 6. Harvesting and threshing: Harvesting may be done by sickle and threshing with thresher. Care should be taken to avoid mechanical mixture. 7. Processing and storage (at 9-10 % moisture): Wheat seeds should have 9 to 10 percent moisture content for storing purpose. To maintain good quality of seeds, it should be cleaned, treated with fungicide and should be properly bagged. The seed should be stored in a dry, clean  MINIMUM SEED CERTIFICATION STANDARD IN WHEAT Particulars Foundation Certified seed seed Germination (%) 85 85 Genetic purity 98 98 (%) Inert matter (%) 2 2 Other crop seeds 10 10 (No./kg) Weed seeds 10 10 (No./kg) Diseased seeds 0.05 0.25 (%) Moisture (%) 10 10 1. Crop Wheat 6. Label No. 2. Variety 7. Net Weight kg 3. Class of Seed: BREEDER SEED 4. Pure Seed % 8. Inert Matter % 5. Lot No. 9. Germination % 2. RICE  SEED OF DRY PADDY/RICE SINGLE PANICLE OF GREEN RICE SINGLE PANICLE OF DRY RICE  2. RICE 1. Selection of the plot: Free from weeds and volunteer plants and should have not been used for growing the same crop in previous year or season. Prepare the land with deep ploughing followed by harrowing so that the transplanted seedlings establish quickly. Plot should be kept flooded for a week before TP 2. Isolation distance: (3 m) 3. Cultural practices: (i) Raising the nursery:  Land for paddy nursery should not have paddy as previous crop to avoid varietal mixture due to volunteer plant.  Long and narrow nursery beds (1 m x 10 m) are more ideal.  Prepare raise bed to facilitate drainage of excess water and also to irrigate the nursery uniformly.  About 80 to 90 beds of the size 10 m x 3 m are sufficient for raising seedlings to transplant one hectare of land. Time of sowing : Early duration varieties – 10th th (ii) Seed rate:  20-25 kg for fine grains and 30-35 kg for coarse grain  The sowing of seeds in nursery may be carried out in row (line) sowing or broadcasting may be done. Irrigate the nursery after sowing the seeds. Recommended plant protection measures and fertilizer application may be made. (iii) Uprooting seedlings and TP: 3-4 wks old seedlings must be transplanted. (iv) Fertilizer recommendation: 120-60-00 kg N:P:K for later varieties and 100-50-00 kg N:P:K for early and mid-late varieties after transplanting. Fertilizer Dose: 120-60-00 i. e. NPK/ha (50 % - basal, 25 % - tillering stage & 25 % - panicle initiation) Spacing should be kept at 20 cm x 15 cm. Maintain 2.5 to 5 cm level of water upto milking stage. 5. Weed control : Butachlor 1.5 kg a.i./ha, 5-7 days after TP. 6. Plant protection: For the control of stem borer use carbofuran 3 % granules @ 20 kg/ha or phorate 10 % granules @ 10 kg/ha. For the control of brown plant hopper and leaf roller spray endosulphan 35 EC @ 1 litre per hectare Disease : Blast, bacterial leaf blight, bacterial leaf streak and brown spot are the important disease of paddy. 7. Roguing: Three times: Roguing of off types and volunteer plants should be done. once 1st Before flowering 2nd At flowering and 3rd At maturity stage. Roguing of wild rice or plants infested by pests and diseases may be done from time to time as required. 8. Harvesting and threshing: Harvest the crop by sickle or combined harvester. Moisture % less than 18 at harvesting. Allow the crop to dry for two to three days till the moisture content reduce to 12 to 13 percent. Moisture % at Threshing time: < 12% Clean the seeds to remove chalf, dust, empty husks and light seeds by winnowing. Store in a gunny bags in a cool and dry place on wooden racks. 9. Av. Yield: 50 to 60 qtl/ha (100 kg)  MINIMUM SEED CERTIFICATION STANDARD IN RICE VARIETY Particular Foundation Certified seed seed Germination (%) 80 80 Genetic purity 98 98 (%) Inert matter (%) 2 2 Other crop seeds 10 20 (No./kg) Weed seeds 10 20 (No./kg) Diseased seeds 0.01 0.05 (%) Moisture (%) 13 13  HYBRID RICE China developed hybrid rice technology in 1970’s In India 14 varieties are released by diff. SAUs Hybrids can be produced in 3 ways 1. Three line system 2. Two line approach 3. Chemical emasculators  SEED PRODUCTION OF HYBRID RICE The successful development and use of hybrid rice technology in china during 1970s led the way for development and release of rice hybrid. In India 14 rice hybrids have been bred and released for commercial cultivation by some the state agricultural universities and private seed companies. Hybrid rice can be produced in the following ways. Three line system : This involves multiplication of cytoplasmic genetic male sterile line (A line), maintainer line (B line) and restorer line (R line). Production F1 hybrid seed (A x R). Two line approach : This involves the use of photoperiod sensitive genetic male sterile (PSMS) and any normal line can serve as a restorer. By using chemical emasculators : Chemicals which act as male gametocytes have been developed which can sterilize the stamen without affecting the normal functioning of pistil. These chemicals are used to emasculate female parent for hybrid rice production. In this method, two varieties are planted in alternate strips and one is chemically sterilized and pollinated by the other.  A line X B line Maintainance of A line: Male sterile Male fertile Male sterile line A is crossed with B line. Seed produced A line from A line is a male sterile and it is used for hybrid seed production. A line X R line Hybrid seed production: Male sterile Restorer A line is crossed with Restorer gene line (R line). Seed produced from male sterile A line is a F1 (Hybrid hybrid Seed and used for Seed) commercial cultivation as hybrid seed.  First Year Wind blown pollen from B B line A line Male fertile Male sterile X - Non restorer First Year Cross made to maintain A line Male sterile Wind blown pollen from R R line/strain X Seed produced in Cross made to isolated field in produce hybrid normal manner seed Second Year Second Year Seeds from Male sterile line are R line/strain Male fertile grown for producing male grown having a sterile plant - Pollen Restorer genes Fig. scheme for producing hybrid sorghum by utilizing cytoplasmic male sterility. Procedure is similar to Hybrid sorghum cross that used in producing hybrid rice, seeds AXR Male fertile bajra etc. produced in isolated field & sold to farmers  STEPS IN SEED PRODUCTION 1. Selection of seed field 2. Isolation (200 m for F, 100 m for C) 3. Synchronization of flowering 4. Methods of improving seed setting – Supplementary pollination (Nylon rope or shaking of panicles of restorers) – Leaf clipping : Cutting of flag leaf prior 1-2 days of panicle emergence, for ensuring crossing – GA3 spraying (60 ppm) at panicle emergence 5. Roguing 6. Harvesting and processing Moisture % less than 18 at harvesting Threshing : M. % < 12  MINIMUM SEED CERTIFICATION STANDARD IN HYBRID RICE Particular Foundation seed Certified seed Isolation distance 200 100 Germination (%) 90 90 Genetic purity (%) 98 98 Other crop seeds 10 20 (No./kg) Weed seeds 10 20 (No./kg) Diseased seeds (%) 0.01 0.02 Moisture (%) 13 13 3. SO R G H UM  SINGLE PANICLE SINGLE PANICLE OF GREEN SORGHUM OF DRY SORGHUM SINGLE PANICLE OF DRY SORGHUM SEEDS OF DRY SORGHUM  3. SORGHUM 1. Selection of seed plot : The land should be free from volunteer plants and weed plants. There should be no Johnson grass in the seed field or within the isolation distance. The field should be well drained. 2. Isolation distance: Particular Foundation seed Certified seed From other sorghum 200 100 varieties Johnson grass 400 400 Forage sorghum 400 400 3. Seed rate, spacing and planting ratio: Seed rate : Female line (Line A) 8 kg/ha, Male line (Line B) 4 kg/ha Spacing : 75 x 10 cm Ratio : Female line to male line ratio is 4 : 2. 4. Synchronization flowering time in male and female parent: Perfect synchronization of flowering time between male and female parent is most important. Differential flowering time may result in non- synchronization of the parents which may result into poor seed set, hence knowledge regarding flowering habit of the parent is very useful for planning of suitable staggering to ensure nicking and there by maximum seed set. 5. Roguing: (BF, F, AF and maturity): It is very important for quality seed production. Before flowering remove all off type plants from both seed parent and pollinator parent. Roguing may be started before off type, volunteers and pollen shedders in female rows start shedding pollens. At flowering roguing should be done every day to remove pollen shedding plants in the female rows. Pre-harvest roguing i.e. the field should be thoroughly rogued before harvesting and after the seed has matured to the stage when we can identify the true plant and seed characters easily. The roguing of diseased heads should also be done critically. 6. Harvesting: Harvest male rows (B lines) first and keep their ear heads separate. The female rows (A line) should be harvested after completion of harvesting of B lines. 7. Seed yield : Average seed yield of 4 to 6 quintals per hectare. MINIMUM SEED CERTIFICATION STANDARD IN SORGHUM Particular Foundation seed Certified seed Germination (%) 75 75 Genetic purity (%) 98 98 Other crop seeds 5 10 (No./kg) Weed seeds 5 10 (No./kg) Diseased seeds (%) 0.02 % 0.04 % Moisture (%) 12 12  HYBRID SORGHUM SEED PRODUCTION BY UTILIZING CYTOPLASMIC GENETIC MALE STERILITY The steps involved in hybrid seed production are as under. Maintenance of parental lines: The line A carrying cytoplasmic genetic male sterility. Line B male fertile (maintainer lines of A) and R line i.e. restorer line used as male parent for the purpose of producing hybrid seed male fertile, pollen restoring line. Production of hybrid seed: This involves crossing of male sterile line A with restorer line (R line) to produce hybrid seeds. The maintenance of parental lines is known as foundation seed production and the production of hybrid seed is known as certified seed production. Maintenance of male sterile lines (Line A):  The male sterile line (line A) carried male sterility due to cytoplasmic genetic factors. It is maintained by crossing with male fertile non-pollen restoring line (non-restorer line) in an isolated plot.  The isolation distance kept is 400 meters.  In a crossing field the planting ratio of line A and B is 4 : 2.  Four to six border rows of line B are planted all around the seed plot.  The seed harvested from line A is male sterile and is used for hybrid seed production as a female parent and for further maintenance of line A.  The seed harvested from line B is pollen fertile and may be used in further maintenance of line A. 1. Seed rate, spacing and planting ratio : Seed rate : Female line (Line A) 8 kg/ha, Male line (Line B) 4 kg/ha Spacing : 75 x 10 cm Ratio : Female line to male line ratio is 4 : 2. 2. Roguing:  It is very important for quality seed production.  Before flowering remove all off type plants from both seed parent and pollinator parent. Roguing may be started before off type, volunteers and pollen shedders in female rows start shedding pollens.  At flowering roguing should be done every day to remove pollen shedding plants in the female rows.  Pre-harvest roguing i.e. the field should be thoroughly rogued before harvesting and after the seed has matured to the stage when we can identify the true plant and seed characters easily.  The roguing of diseased heads should also be done critically. 3. Harvesting: Harvest male rows (B lines) first and keep their ear heads separate. The female rows (A line) should be harvested after completion of harvesting of B lines. Production of hybrid seed: Hybrid seed is produced by crossing male sterile line (line A) with specified restorer line (line R) in an isolated field. This is hybrid seed that is to be sold to farmers. Important Points for Hybrid seed production in Sorghum: For any large-scale seed production of hybrid sorghum, cytoplasmic male sterile lines are required. Cytoplsmic male sterile lines like CK-60, MSCK-60A, MS-2219, MS- 2077A, PMS-1063A etc. are available which can also be introduced into the local varieties through repeated backcrossing. In sorghum, Stephen and Holland (1954) discovered cytoplasmic male sterility (CMS) designated as milo cytoplasm in the progenies of a cross between two cultivars, milo and combine kafir, with milo as the female and kafir as the male.  ASSIGNMENT: Q – 1. Do as Directed. (i) How much isolation distance is kept for foundation and certified seed production program of rice? (ii) Enlist the general principles of seed production. (iii) Which is the dwarfing gene for wheat crop? (iv) Which are the various CMS system has been identified in rice? (v) Why the seeds of maize are produced through double cross technique? (vi) Why seed production programme should be kept up in its area of adaptation? Q – 2. Elucidate the procedure for hybrid seed production in paddy/wheat. Q – 3. Explains steps involved in hybrid seed production in sorghum.