What rescue measures are there after rice is flooded
Rice fields flooded for 1-4 days below 25°C suffer little damage; flooding for 1-4 days above 30°C can cause abnormal grain filling in rice; flooding for 1-4 days above 40°C can cause rice to wither and die with total crop loss.
When rice is flooded at the seedling stage, the seedlings become thin and elongated with yellowing leaves, and generally are difficult to recover; at the tillering stage, the lower leaves necrose and the heart leaves curl, and after the water recedes the leaves wither, but generally do not rot; at the jointing stage, the plants become thin and weak and are prone to lodging and breaking; at the booting stage, resistance is weakest, and rotten ears and deformities easily occur, reducing the seed-setting rate; at the grain-filling stage, the lower leaves wither and yellow, the top leaves yellow, the grains sprout on the ears, grain weight decreases, and grain quality deteriorates. Therefore, rescue measures should be taken promptly after rice fields are flooded.
Drainage and leaf washing: Drain water promptly so the rice seedlings emerge above the water as early as possible, and promptly wash the mud off the leaves. When draining, drain gradually and slowly, not all at once, to improve the adaptability of the rice plants. Lodged rice seedlings should be promptly set upright, and rotten leaves and diseased leaves should be cut off.
Timely topdressing: Promptly apply ear-grain fertilizer and foliar fertilizer. According to the condition of the seedlings, apply 3-5 kg of urea per mu. During the emergence of the flag leaf and the grain-filling stage, spray monopotassium phosphate foliarly, using 75-100 grams per mu, mixed with 50 kg of water, spraying 1-2 times.
Shallow-water intermittent irrigation in the later stage: After heading, shallow-water intermittent irrigation is preferable, to enhance root vigor, extend the lifespan of functional leaves, and strengthen the stress resistance of the rice seedlings. Intermittent irrigation means after the first irrigation, let the water drain naturally for 1-2 days, then irrigate a second time, letting it dry and wet alternately until maturity.
Timely prevention and control of pests and diseases: Generally, flooded rice fields suffer severe pest and disease damage. From late July to early August, use agents such as jinggangmycin to broadly prevent and control sheath blight 1-2 times; 3-5 days before boot breaking, use propiconazole and difenoconazole to prevent and control rice false smut. At the same time, promptly control pests such as the third-generation yellow stem borer, rice leaf roller, and rice planthopper.