Southern "primary resistance and four defenses"

Southern "primary resistance and four defenses"

Experts predict that there is a high probability of high temperature and drought in the late stage of rice growth. At the same time, high temperature heat damage may occur in the middle and lower reaches of the Yangtze River during the heading and flowering stage. The late stage of direct seeding rice with delayed growth process is subject to increased risk of low temperature, and diseases such as sheath blight The degree is aggravated. In view of the current situation of rice seedlings in the first season in the south and the weather situation in the middle and late stages, it is necessary to focus on “one primary resistance and four preventions” (resistance to flood control, drought prevention and protection, prevention of high temperature and heat damage, prevention of pests and diseases, and prevention of cold and wind). Promote the transformation of the seedlings and set up a shelf for high yield.

The first is to resist flooding and draining, and promote the recovery of growth. When rice is flooded from tillering to jointing stage, the growth process is almost stopped, the heading period is elongated, and the growth period is delayed by 2-3 days. For the flooded fields, timely and divided drainage should be combined with the washing of seedlings and light fields; proper control of the water layer, high temperature and sunny days can not drain the water at one time, not only to prevent the dead seedlings, but also to improve the rhizosphere environment to promote root vitality. After the disaster, timely supplement the quick-acting nitrogen fertilizer and potassium dihydrogen phosphate to promote the recovery of growth; after the water recedes, strengthen the prevention and control of pests and diseases to prevent the spread. According to the local season, according to the local season, grasp the time limit, select the early maturing early rice varieties and replant the seeds “early turn over late”; the flooded uncultivated fields can also cut the seedlings in time, properly apply the germination-promoting fertilizer, and regenerate and regenerate. Rice, reducing production losses.

The second is the alternating wet and dry, strengthening group regulation. For the mid-season rice that is still in the tillering stage, when the number of stems of the population reaches 80%-90% of the expected number of spikes, the natural water-breaking field will be put on the field, and the hybrid rice field should be placed early and gently, so that the soil in the whole field is not settled. Feet, the surface of the soil surface sees the new root, the leaves of the rice plant stand up, and the leaf color fades and appears yellow. The seedling peak of the hand-inserted rice is controlled at 1.3-1.4 times of the appropriate number of panicles, the control of throwing japonica rice and machine-planting rice is 1.4-1.5 times, and the direct seeding rice can not exceed 1.6 times. The prosperous and prosperous groups of soils are appropriately placed, and the small and medium-sized groups in the soil fertility are lightly placed. From the jointing to the 15 days after heading, the 2-4 cm water layer and the dry and wet alternate gaps are used for wet irrigation. The grain is grouted to one week before harvesting, and 2-4 cm water layer and lightly dried (15 cm deep and high yield bottom) are implemented. Alternate dry and wet irrigation to ensure the moisture required for grain filling, improve root activity and leaf photosynthetic function, and increase seed setting rate and grain weight. Adhere to the water cut one week before harvesting, avoid water cut too early, avoid poor solidity, significantly reduce yield, and poor quality of rice.

The third is scientific fertilization, promoting flower and flower to increase grain weight. The application of panicle fertilizer should be carried out on the basis that the peak of the group has passed, and the leaf color is obviously faded and "yellow". For the field with suitable stem number and normal leaf color, the panicle fertilizer should be applied twice in the inverted 4 leaf and the inverted 3 leaf stage. The indica rice should not exceed 40% of the total nitrogen application in the whole life, and the indica rice should not exceed 30%. For the field with small population of stems and early yellow leaves, the panicle fertilizer should be applied 2-3 times in the beginning of the inverted 4 leaves and the inverted 3 leaves, and the dosage should be increased by 10%-30%, which will weaken and strengthen. For the field where the number of stems and stalks is too large and the leaf color is deep, it is generally delayed in the down 3 or 2 leaf stage due to the reduction of seedlings. In the jointing stage, potassium and silicon fertilizers are reasonably applied according to the soil potassium and silicon nutrient abundance. Generally, the potassium is 5-10 kg of potassium chloride and 5 kg of silica. Indica rice is prone to premature aging, and can be applied properly in the early stage from heading to filling. Generally, 3-5 kg ​​of ammonium sulfate or urea is used in the mu, and root dressing can be adopted to promote grain filling and increase 1000-grain weight.

The fourth is to adjust the temperature of the water to prevent high temperature and heat damage. Rice that has entered the booting to heading stage, if it continues to have a high temperature above 35 °C, it will affect the pollination and seed setting rate of the lotus flower. Deep water irrigation (about 10 cm in the water layer) can be adopted to adjust the temperature of the water layer and reduce the temperature of the ear layer. Spraying phosphorus and potassium fertilizers and other measures to enhance the resistance of rice plants to high temperatures, to alleviate or mitigate high temperature hazards. For drought-stricken paddy fields, it is necessary to make full use of various water sources, timely replenish water, improve irrigation efficiency, and promote rice growth and development.

The fifth is early maturity to prevent cold damage. For the direct-seeded rice in the Yangtze River valley, the late-maturing rice that is delayed by the flood season, and the late-maturing rice that has been rehabilitated after flooding, it is necessary to adopt early management measures to accelerate the fertility process; Comprehensive measures such as deep water, spray gibberellin, and spray foliar fertilizer to reduce the effects of low temperature.

Sixth is the unified defense and strict control of pests and diseases. The current high temperature and high humidity in the field are very suitable for the spread of pests and diseases. It is necessary to strengthen the monitoring of diseases and insects, accurately grasp the dynamics of pests and diseases, and strengthen the overall prevention and control of pests before and after the heading stage. Focus on strengthening the control of rice leaf roller, rice planthopper and rice blast, sheath blight and rice smut. The prevention and treatment of rice smut should be carried out 10-15 days before the break; vigorously promote professional rule. Improve the level of green prevention and control, reduce the amount of pesticides, and effectively reduce the loss of pests and diseases.

(Original title: How to fight disasters in the middle and late stages of the rice season in the south)