How to prevent and control rice red blight? These 4 methods work fast

After good early growth, rice enters the reproductive growth stage of the middle and late periods. Strengthening field management at this stage has a great relationship with the yield and quality of rice. So, how can field management in the middle and late stages of rice growth be done well?

1. Timely field drying. Field drying should generally be carried out when rice is not sensitive to water reaction, that is, it is more suitable from the late tillering stage to the early young panicle differentiation stage. The following principles should be followed during operation: fields with sufficient and vigorous seedlings should be dried appropriately earlier; where the mud foot is deep and there is excessive growth, drying should be heavier, otherwise lighter; fields with poor water retention should not be dried heavily; saline-alkali paddy fields generally cannot be dried.

2. Scientific irrigation. The long panicle stage is the peak period of physiological water demand in the entire life of rice, especially from 2-14 days before heading, when it is most sensitive to water and must not lack water, so as not to affect spikelet differentiation and development. After field drying, rewatering should be done by shallow water and frequent irrigation, adopting the intermittent irrigation method of "old water not dry, new water not added." Scientific irrigation after field drying not only greatly saves precious water resources, but also improves the soil ecological environment, maintains and enhances root activity, and facilitates the absorption and transport of nutrients.

The irrigation method during the heading and grain-filling period is: deep water at heading, shallow water at grain filling, moist conditions for nourishing grains, and drainage and drying about 5 days before harvest. Never cut off water too early, as this affects grain weight.

3. Skillfully applying panicle and grain fertilizer. Panicle fertilizer is generally applied after young panicle differentiation begins, and the amount should be determined according to the field growth of rice: where the number of stems and tillers is too large and leaf color is dark, apply less and later, with about 2.5-3 kg of urea per mu; where the number of stems and tillers is insufficient and leaf color is yellow and uneven, apply earlier and more heavily, with about 5 kg of urea per mu.

Increasing grain fertilizer mainly supplements the insufficiency of panicle fertilizer. The best application period for grain fertilizer is when rice leaves can naturally turn lighter before breakage, that is, topdressing is suitable from 2-3 days before heading to initial heading. Grain fertilizer is generally best as urea, with about 2.5 kg applied per mu. However, for fields with sufficient soil fertility, excessive growth, and dark leaf color, grain fertilizer should not be applied, in order to prevent excessive vegetative growth and delayed maturity, which affect yield and quality. To prevent premature senescence of plants after heading, foliar spraying should also be carried out at this time. The method is: use 1% urea mixed with 0.2% potassium dihydrogen phosphate, and spray 50-70 kg of the solution per mu each time. Spray in the afternoon or evening on sunny days, and spray both the front and back sides of the leaves.

4. Pest and disease control. In the middle and late stages of rice growth, emphasis should be placed on controlling bacterial leaf blight, sheath blight, rice false smut, and pests such as the striped stem borer, yellow stem borer, and rice planthopper, and these pests and diseases often occur in combination. Based on this actual situation, pesticide mixing technology should be used for combined control. For example, when bacterial leaf blight and yellow stem borer occur together, a mixed solution of leaf blight ning and bisultap can be used for control, which saves labor and time and also achieves good control effects.