The correct method for soaking and germinating hybrid rice seeds

Now is precisely the main spring production season. A small number of farmers, due to improper operation during the soaking and germination process, have encountered problems such as seeds turning sour and smelly and poor sprouting. Therefore, when soaking and germinating seeds, attention should be paid to:

1. Sun-drying the seeds: one week before soaking, choose a sunny day and sun-dry the seeds for 3-4 hours or half a day, then place the sun-dried seeds in a dry, cool place to cool thoroughly, so as to promote the respiration of the seeds and enzyme activity, which helps improve the seed germination rate and germination vigor; sun-drying can also kill some of the pathogens attached to the rice husk. It is better to sun-dry the seeds on a bamboo tray or on mud ground, but the rice seeds must not be spread directly on a cement floor or stone slab to dry, to prevent sun damage to the rice seeds.

2. Seed selection: use clean water for seed selection, scoop out the blighted grains floating on the surface, and select plump rice seeds, so as to cultivate neat and robust seedlings. Because most two-line hybrid varieties have poor plumpness and the seeds are expensive, the non-plump seeds should be fully utilized; it is best to germinate and sow them separately, with focused care, so as to cultivate neat and robust seedlings. If seeds are sufficient, there is no need to use half-filled seeds.

3. Seed soaking and disinfection. After washing the seeds clean with clean water, put them into clean water and pre-soak for 12 hours first (during the pre-soaking period, change the water about once every 4-6 hours, and wash the seeds clean), so that the pathogen spores attached to the seeds germinate and become active, then soak the seeds for 12 hours in a 300-fold strong chlorine disinfectant solution. The disinfectant solution should be one cun above the seed surface (do not change the water during disinfection), then repeatedly rinse with clean water until the residual solution is completely removed. After washing clean, continue to soak the seeds in clean water for 12 hours, then take them out to germinate.

4. Germination: many farmers like to put the seeds in woven bags to germinate, and even because the temperature cannot rise, they put the seeds under the sun to bake, often causing sprout burning. The best method is to use double-layer, disease-free, moist burlap sacks to germinate. Spread a layer of disease-free rice straw on the ground, lay one burlap sack out flat, spread the seeds evenly on it, then cover with another burlap sack on top; in the middle, only pay a little attention to whether water needs to be added. They can also be put into burlap sacks or bamboo baskets, with rice straw packed around them to keep them warm. After the paddy seeds heat up, control the temperature at 35-38 degrees C. If the temperature is too high, turn the pile; if too low, the temperature of the warm water used should be increased. After about 20 hours, the paddy seeds can show white and break through the hull.

5. Timely sowing: after the paddy seeds show white, adjust the temperature to 25-30 degrees C, and germinate at a suitable temperature to promote root growth. When the sprout grows to half a grain long and the root grows to 1 grain long, they can be sown in the field. During germination, always pay attention to changes in the paddy seed temperature, to prevent the paddy seed temperature from being too high or too low. If the temperature is too high, the seeds will be burned; if too low, they will turn sour, smelly and alcoholic, affecting the germination rate.

6. Sprout hardening: before sowing, spread the well-germinated paddy seeds out at room temperature to harden the sprouts for 3-6 hours, then sow. This makes the paddy seeds adapt to the air temperature and improves the seedling survival rate.

7. Sowing methods: at present, mainly water-raised seedlings and dry-raised seedlings are used. For healthy, plump seeds with strong germination vigor, both water-raised and dry-raised methods can be used; for seeds with poor color and plumpness, weak germination vigor, or even pathogen infection, it is best to use dry-raised seedlings. Seedlings grown by dry raising have the characteristics of being short and strong, with strong root activity and strong cold resistance; after transplanting they start growing quickly, tiller vigorously, and increase the panicle-bearing rate and seed-setting rate. They can not only be sown early and transplanted early, maturing earlier, but can also save seedling field, plastic film, seeds, labor input, fertilizer input and water use.

8. Preventing seedling rot: seedling rot is the general term for seed rot, sprout rot and dead seedlings. Taking rooting and greening as the boundary, seed rot and sprout rot occur before rooting and greening. Dead seedlings occur after rooting and greening, and are especially serious at the 2-3 leaf stage. Methods for preventing and controlling seedling rot: first, spray chemicals to sterilize; for soil sterilization, mainly use a mixture of dexon (1:500) and copper sulfate (1:1000), 150 kg, sprayed on the bed surface with coarse droplets; second, supply water in time to prevent bacterial wilt dead seedlings; third, if the sprouts are washed by rainwater during the sprout stage and the seed sprouts are exposed, cover material can be added or dilute mud slurry can be evenly sprinkled on the bed surface, both of which can increase the emergence rate; fourth, sow appropriately thinly to cultivate strong tillering seedlings.