II. Production technology
1. Selection of suitable production environment based on adoptability
- Crop specific temperate, sub tropical and tropical environment should be selected based on their genetic adoptability as it results in better survival capacity of a variety under given environmental condition.
- For example temperate crops will not set seed in tropical conditions and the virus free production of seed potato is possible only in plains though the multiplication rate is higher at hilly areas.
- In general the area selected should have the following characteristics
2. Selection of land
- Free from volunteer plants, weed plants and other crop plants.
- In the proceeding season the same crop should have not been grown.
- Avoid areas where isolation is a problem.
- Having a well distributed rainfall in the cropping period.
- Avoid areas of very high and low rainfall.
- Prevalence of cool and dry weather is preferable.
- Avoid high temperature and relative humidity areas where germination is poor.
- Avoid heavy windy areas.
- Avoid coastal belts and marshy places and heavy windy areas.
- Avoid areas of endemic diseases and pests
- Select compact areas for hybrid seed production.
- Available of skilled labourers especially in hybrid seed production of crops.
- Near the processing operations with transporting facilities and marketing facilities.
3. Selection of season
- Select well leveled field for uniform maturity.
- Select nearest to irrigation sources select fertile fields.
- Avoid weedy fields particularly the presence of abnoxious weeds.
- Avoid problem fields like alkaline, saline and sodic soils.
- Avoid sick fields.
4. Selection of Seeds
- Proper season for specific kind of crop.
- Off season is better to avoid isolation problem.
- Selection of crop and varieties
- The variety should be adapted to the agro climatic conditions of the region.
- The variety should really be a high yielder. The variety should be a popular one. Select varieties having wide adaptability.
- Select photo and thermal insensitive varieties drought resistant, pest and disease resistant one.
- Should possess other desirable attributes namely, earliness of the crop, seed quality etc.
- The seed used for raising a seed crop should be of known purity, appropriate class (farmers can produce certified seed). Breeder Seed can be produced only by the university and Foundation Seed by State Seed Farm / and invariably obtained from an authorized official agency while purchases of seed the following should be carefully examined.
5. Preparation of land
- B.S - N.S
- F.S - B.S are the basic material for seed
- C.S - F.S production
- Commercial - C.S
- Other details on the tag - agency, purity, germination,Validity period,Verify that all the bags of the same variety.
Types of isolation
- The land for the seed crop must be prepared well. Good land preparation helps in improved germination, deep ploughing results in destruction of potential weeds. It also aids in water management and good uniform irrigation. Perfect leveling is very important well fertile, avoid sick fields, alkali and sodic soils.
- Isolation of seed crops: The seed crop must be isolated from other contaminating crops. The isolation of a seed crop is usually done by providing distance between seed fields and contaminating fields.
6. Pre-sowing treatment
- Physical or distance isolation - expressed in meters.
- Time isolation - taking up of sowing in different dates (i.e.,) 30 days for most of the crops except in crops having indeterminate growth habit.
- Barrier isolation - if the above said isolation is not possible we can go for barrier isolation by erecting tall shelter trees.
- Physiological isolation - differ in flowering due to change in altitude.
The following points should be considered.
- Seeds should be appropriately treated. Pre-sowing seed treatments with nutrients.
- Duration of soaking
- Soaking water to seed ratio.
- Old seed or new seed.
- Quantity of micro, macro nutrients or growth regulators. Seed treatment to break dormancy.
7. Seed rate and nursery
- Scarification - acid and mechanical,Chemical treatment
- Seed hardening with different chemicals.
8. Time of planting
- Seed rate should be based on seed lot viability and vigour.
- If not there will be lot of gaps in the field.
- Indirect sown crop or seedlings may not be sufficient to cover the targeted area to transplant or if high the seed will be wasted.
- Line sowing is advisable for seed crop adopting correct spacing then only we can achieve required population producing equal opportunity to each plant to develop and mature which is not possible in broadcasted crop.
9. Method of planting / sowing
- The seed crops should invariably be sown or transplanted at an optimum age of seedling at their normal planting time.
- At the time of planting there should be sufficient soil moisture for germination to take place.
- Lower seed rates than usual for raising commercial crops are desirable because they facilitate roguing operations and inspection of seed crop.
10. Depth of sowing
- The seed crops should invariably be sown in rows with the exception of thickly sown crops where the sowing could be done by broadcasting.
- The sowing of seed crops in rows helps in conducting effective plant protection measures, roguing operations and field inspections.
- For hybrids planting of two parent’s namely female parent line and male parent line has to be done in a definite proportion e.g. 5:1 or 9:1.
- If the hybrid seed production involves male sterile lines, border rows of the male parent may also be sown (or) transplanted.
- Depth of sowing is extremely important in ensuring good plant stands.
- Small seeds like cucurbits, solanaeceae and malvaceae vegetables should usually be planted shallow but large seeds could be planted a little deeper.
- Seeds would emerge from greater depths in sandy soils than in clay soils, and also in warm soil as compared to cold.
- In dry soils, seeds should be planted slightly deeper so that they come in contact with moisture.
- Either manually or by using chemical means. once or twice manual weeding during early stage of crop growth will help in controlling weeds and will provide favourable conditions for root formation and development.
13. Nutritional factors
- Optimum and timely irrigation is must.
- Over irrigation can promote vegetative growth, lodging, nutrient imbalance while under irrigation delay flowering, stunted growth reduced filling and immature drying.
- Hence irrigation at critical stages like sowing, life irrigation, flowering and fruit, pod formation, seed filling and seed maturation is must.
- With holding irrigation at harvest promotes earlier and quicker ripening, irrigation can also be used for staggering and achieving synchronization in hybrid seed production.
- Lack of N delay the field emergence, lack of P delay flowering, K is responsible for filling and lusture the crops.
- Zn is essential for fertilization.
- Selenium is responsible for germination in onion.
- Cu deficiency leads to poor embryo growth.
- Manganese deficiency causes marsh spot in peas.
- Boron deficiency results in poor seed development and hollow heart in peas.
- Iron deficiency causes sterility, Molybdenum also contribute bleaching in peas.
- Roguing in most of the field crops may be done at any of the following stages as per needs of the seed crop.
15. Diseases and pest control
- The rouging at vegetative / pre-flowering stage in cross-pollinated crops is extremely important to avoid genetic contamination.
- The roguing at flowering stage is equally important, perhaps even more important than at the vegetative stage. In hybrid crops, where male sterility is being used, special care is required in the removal of pollen shedders. In many crops removal of ear heads infested by seed borne diseases.
- Roguing at maturity stage is also equally important in the removal of the various contaminants affecting the physical purity of the seed.
- In root and vegetative crops a roguing at harvest time for confirmation of fruit / tuber / root characteristics is necessary.
- Sometimes, inspection is also being attended before seed extraction to select true to type fruits and pods to ensure genetic purity.
- The seed crop should be maintained without any pest and disease attack. The leaf curl virus and yellow vein mosaic infestation drastically reduce the yield and quality in tomato and bhendi, respectively.
- The fruit / pod bores infestation causes seed discolouration and result in poor quality in terms of viability and storability. Similarly bruchid attack in lab-lab leads to very poor storability.
- There is a heavy damage in flowering and seed set in crucifer vegetables due to diamond back moth incidence.
- The time of sowing should be adjusted in such a way that the maturation does not coincide with rainy season or at high humidity weather periods.
- The moisture content.
- Physiological maturity.
- Avoid delayed or premature harvest.
- Once over harvest in agricultural crops.
- Staggered harvest in the horticultural crops.
- Harvesting symptoms according to the different crops.