Shallow water warming for rice to promote tillering, fertilization with "two preventions" to grow strong seedlings

Due to the impact of unfavorable weather conditions such as low temperatures, frequent rain and insufficient sunlight, rice has been slow to turn green, with yellow leaves, few tillers and delayed growth. For this reason, rice expert Xu Yirong, after an on-site inspection in the Heilongjiang reclamation area, proposed countermeasures such as shallow water warming to promote tillering, fertilization with "two preventions" to grow strong seedlings, and fitness-based disease prevention.

First, water layer management must be done well: deep water is a heat-preservation measure, shallow water is a warming measure, and not establishing a water layer is a cooling measure. For plots with deep water formed by rainfall, drainage must be carried out promptly to raise temperature, promote root growth and promote tillering. Comprehensive measures should be adopted to warm well water, ensuring that the water temperature reaches 17°C, 18°C and 20°C~22°C during the tillering stage, meiosis stage and heading-filling stage respectively.

Second, fertilization should achieve the "two preventions" for strong seedlings. First is fertilization. Tillering fertilizer should be applied early, and the amount of tillering fertilizer should be increased (planned tillering fertilizer amount increased by 10%~20%), applied immediately after rice turns green; of this, 80% of the tillering fertilizer is broadcast over the whole field, and the remaining 20% of nitrogen fertilizer is applied 5~7 days later, wherever leaves are yellow and plants are weak. Second is weed control. For the second weed control, amide herbicides should be used before barnyardgrass reaches the 1.5-leaf stage, and organophosphorus herbicides before barnyardgrass reaches the 2.1-leaf stage; the application method is poisoned soil or spray-throwing, and the poisoned fertilizer method is not recommended. Water layer 3~5 cm, keep water for 5~7 days. Third is controlling leafminer and rice leaf beetle. At present, leafminer has already occurred in patches; field surveys should be strengthened, and when one patch is found it should be controlled promptly, using agents such as Aimeile and Decis.

Furthermore, field diagnosis and regulation should also be strengthened. First, diagnose the leaf age progress in a timely manner. If low temperatures continue, growth delay may occur, so the leaf age progress should be diagnosed promptly; the best method is the leaf-marking method, selecting representative plots and marking the 3rd, 5th, 7th and 9th leaves of rice. If an increase in leaves is found, foliar fertilizers containing silicon and foliar fertilizers containing phosphorus and potassium should be sprayed to promote early maturity. Second, comprehensively use stem number diagnosis and leaf color diagnosis to apply adjustment fertilizer. After the critical leaf position for effective tillering of rice (7.5-leaf stage for 11-leaf varieties), if the number of stems per sq m is less than 450~500 panicles, the amount of adjustment fertilizer should be increased to promote large panicles. If the number of panicles is too large, fields should be dried promptly to control ineffective tillering.

Regarding fitness-based disease prevention, careful work should be done to prevent and control the "five diseases" of rice: rice narrow brown leaf spot, bacterial brown spot, sheath rot, rice blast and brown panicle. Under current conditions, rice narrow brown leaf spot and bacterial brown spot are prone to occur, and 2% Jiadoumi 80 ml + 25% prochloraz 60 ml per mu can be selected; to control rice brown panicle, 3.5% polyoxin 80~100 ml per mu or 50% iprodione 75 ml per mu can be selected. Carry out rescue from pesticide injury according to rice seedling conditions; after turning green, apply biological fertilizer together with tillering fertilizer (expired biological fertilizer must not be used); at the 4.5~5.5-leaf stage, spray plant endogenous hormone regulators such as Huangjia natural brassinolide, Kangkai and Haijingling, and foliar fertilizers such as amino acid fertilizer and Yiwei.