Key Technical Points for Post-Flood Care of Submerged Rice

After rice is submerged, in view of the actual situation of severe damage to the root system and leaves and a serious decline in the total number of stems and tillers, measures should be taken to nourish the roots, protect the leaves and promote tillering, so as to increase the percentage of productive panicles and strive for heavier grains.

1. Make an all-out effort to drain the standing water from the fields. The standing water in the fields should be drained as early as possible, and the fields should be exposed and the seedlings hardened to improve the soil's physical and chemical properties and remove toxic substances. For fields submerged for a relatively long time, the water can be drained completely in one go during rainy weather; in hot weather with strong sunlight, dehydration should be carried out gradually, first allowing the upper part of the rice plants to emerge above the water surface, then dehydrating at night to aerate the soil, and irrigating by day and exposing at night, so as to help the rice recover its growth.

2. Water and slurry management varies with the seedlings. After drainage, on the basis of the rice field gradually settling and consolidating, for fields submerged for a short time with a relatively high number of seedlings, carry out light drying 2 to 3 times; for fields with more severe damage and insufficient seedlings, use moist irrigation, first exposing the field and then lightly drying it, so as to help strengthen the early-born tillers and protect the later-born tillers. Afterwards, in view of the characteristics of a large proportion of high-position tillers and inconsistent growth progress, pay attention to "nourishing the old rice"; generally, 5 days before harvest, a "horse-racing water" irrigation should still be applied once.

3. Apply recovery fertilizer in a timely manner. Submerged rice has a weak root absorption capacity, so it is not advisable to apply a heavy fertilizer all at once. After draining and exposing the field, apply fertilizer once, and apply it again after 5 to 7 days, using 5 kg of urea and 20 kg of compound fertilizer per mu. Afterwards, apply flower-promoting fertilizer and flower-preserving fertilizer well according to the seedling condition, and carry out appropriate foliar topdressing after heading. For fields with a later growth progress, spraying Huimanfeng, "920" and potassium dihydrogen phosphate at the initial heading stage can promote uniform heading, enhance photosynthesis, and increase the seed-setting rate and 1000-grain weight.

4. Strengthen pest and disease control. After submerged rice resumes growth, its leaves, tillers and stems are relatively tender and are prone to damage by pests such as the rice leaf roller, and delayed growth and development also increases the probability of occurrence and damage by the brown planthopper and the yellow stem borer; submerged rice seedlings have damaged leaves and more withered leaves, and are also prone to infection by bacterial leaf blight, sheath blight and rice blast, so the control of these pests and diseases must be strengthened.