Technical Opinions on Rice Breeding and Transplanting in the Middle and Lower Reaches of the Yangtze River

Abstract:

The middle and lower reaches of the Yangtze River has a large planting area and high yield per unit area, which is an important rice producing area in China. At present, "long summer" has passed, and rice seedlings have been sown in the middle and lower reaches of the Yangtze River. However, since the beginning of April, there has been a lot of heavy rainfall in this area, which has affected the preparation of seedling fields, the appropriate period of seedling raising and the cultivation of strong seedlings. In view of the current meteorological conditions and production practice, the technical opinions on rice planting and transplanting in the middle and lower reaches of the Yangtze River are put forward.

1. sow at the right time, and sow sparsely and evenly.According to the seasonal arrangement, stubble connection and variety growth period, timely sowing and seedling raising can last from late April to late May. Due to the rain this year, the seedling field should choose a higher terrain, less susceptible to waterlogging. According to the field area, variety type and transplanting method, the area of the seedling bed and the number of seedling trays should be calculated to ensure that sufficient seedlings are raised. For artificial transplanting, dry seedling or wet seedling can be used, and the ratio of seedling field to field is 1: 20 and 1: 10 respectively. For machine transplanting, 20-25 plates of hybrid medium indica rice per mu, 70-90g of dry seeds per plate; 30-35 plates of regular japonica rice per mu, 100-120g of dry seeds per plate. Whether it is a seedling bed or a seedling plate, it must be thinly sown and evenly sown to lay the foundation for cultivating strong seedlings. Where conditions permit, it is necessary to actively promote the cultivation of seedlings in factory greenhouses and adhere to dry and dry breeding. Direct seeding rice should be sown evenly, and mechanical precision strip (hole) sowing should be promoted.

2. water and fertilizer regulation to cultivate strong seedlings.Heat preservation and moisture retention to ensure quick budding and full emergence. The field seedling tray shall be nursed with water in the field and the seedbed shall be wet. regular seedling raising before emergence of wet irrigation, after emergence of shallow wet irrigation. Factory plate seedling raising according to technical procedures, generally with special seedling raising substrate, without fertilization. Field plate seedling raising mostly uses field mud and seedling strengthening agent, and applies appropriate amount of delivery fertilizer before transplanting. Seedbed seedling raising (regular seedling raising) apply 20-25kg of compound fertilizer per mu as base fertilizer, which is used in harrowing or tillering fields. At the stage of two leaves and one heart of seedlings, apply 3-4kg of urea per mu as weaning fertilizer. 3-4 days before transplanting, apply 5kg of urea per mu as starting fertilizer. If the seedling age is longer, the seedling height can be controlled by spraying paclobutrazol.

3. fine ground preparation, improve quality.Whether it is machine transplanting, manual transplanting, throwing or direct seeding of rice fields, the quality of field preparation should be flat, soft and uniform. In particular, if the previous crop of straw is returned to the field in full, it should be crushed, scattered evenly and buried in the soil. The height difference of the whole field is not more than 3cm, the field surface is "clean", there are no weeds and sundries, no scum, etc., and the topsoil is fine and coarse, rotten and solid. After the paddy field is leveled, it shall be moderately settled. Sandy soil shall be settled for about 1 day, loam shall be settled for 1-2 days, and clay shall be settled for 2-3 days. When mud precipitates, topsoil is moderately soft and hard, and the machine does not sink during operation, keep the thin water machine inserted. Throwing or transplanting should be done when the moisture on the surface of the field has just dried.

4. timely transplanting, foot seedling planting.For machine transplanting and throwing seedlings, strictly control the seedling age of 15-20 days and transplanting of 3-4 leaves, and avoid over-seedling age. For hand transplanting and throwing seedlings, the seedling age should be controlled within 25 days. When transplanting, the appropriate planting specifications shall be determined according to the species, with more tiller seedlings being planted less and less tiller seedlings being planted more. regular japonica rice with panicle number type or panicle grain type is inserted into 1.7-19000 holes per mu, with 3-4 seedlings per hole. Large spike type hybrid japonica rice is inserted into 1.5-17000 holes per mu, with about 2 seedlings per hole. Large spike type medium indica hybrid rice is inserted into 1.2-15000 holes per mu, with 1-2 seedlings per hole. For the seedling throwing field, it is necessary to move the density and make up the thinning, so that the seedlings in the whole field are evenly distributed.

5. pest control, chemical weeding.The current rainy weather conditions conducive to the development of sheath blight, rice blast, rice planthopper and other diseases and insect pests. It is necessary to strengthen the monitoring and forecasting of diseases and insect pests, make preparations for prevention and control in advance, and actively promote unified prevention and control. Spray a long-acting pesticide 3-5 days before transplanting, and take the seedlings to the field with the medicine. For direct seeding rice fields, weed control should be strengthened, and tillage and weeding and chemical sealing weeding before transplanting (sowing) should be strongly advocated.

6. flood prevention, disaster prevention and mitigation.According to the forecast of the Meteorological Department, due to the influence of the super-strong El Niño, the overall deviation of my country's climate year this year, the flood season (May-September) has more precipitation, especially the middle and lower reaches of the Yangtze River and the eastern part of the southwestern region, and severe floods may occur. Floods may occur in some farmland in Jianghan and northern Jiangnan, which is not conducive to the growth and development of rice. It is necessary to formulate technical opinions on disaster prevention and mitigation as soon as possible, make preparations for flood prevention and waterlogging in advance, and rush to collect and dredge ditches in order to drain water, so as to avoid flooding of seedling fields and accumulation of water on seedling beds. At the same time, remedial measures should be taken in advance to reduce disaster losses.