Early rice rotten control and early grasp

Rice rotting is a general term for rotten seed, rotten buds and dead seedlings in rice seedling stage. According to the weather forecast, the fact that there is a lot of rain this spring is conducive to the occurrence of early rice rot. If the prevention and control are not strengthened, the early rice yield will be seriously affected.

First, the symptoms

1. Corrosion rotten buds: easy to attack under low temperature and high humidity conditions, the roots, buds outside the base of the glume produce a white jelly-like material, grow into a cotton-like mycelium, and later become brown or green brown, young buds Yellowish brown dead.

2. Standing rotten buds: The roots of the root buds are immersed with light brown spots. They grow into white wooly hyphae, and some grow white or pale pink moldy. The young buds are curled at the base and easily pulled off. The roots turn brown and rot, and they cluster and die.

3. Dead seedlings: There were blue-green dead seedlings and yellow dry-type dead seedlings. The wilting dead seedlings do not spit water at the tip of the leaf, and the heart leaves are wilting in a tube shape. The lower leaves are then wilted and reeled. The seedlings are stained with green and die, the roots are dark and the root hairs are scarce. Yellow dry-type dead seedlings: Dead seedlings start from the lower leaves, the tips of the leaves turn yellow gradually to the leaf base, and then expand from the lower to upper leaves. Finally, the stem base is softened and browned, and the seedlings are brown and dead.

Second, control methods

1. Strengthen Water and Fertilizer Management: In the bud stage, rooting and standing seedlings are mainly used to keep the surface moist. It is not possible to pass the water in the morning, and water is needed to protect the bud when the temperature is low. After the first leaf is unfolded, shallow water can be properly irrigated, 2-3 leaf leaves can be irrigated to reduce the temperature difference, and heat preservation can be used to prevent freezing. The cold wave is about to be filled with water to protect the seedlings, and the cold air is turned into normal management later. Film seedlings should be uncovered from 8 to 9 am, and thin skin should be applied before venting to prevent drastic changes in temperature and humidity. The seedlings found dead in the paddy field once a day "running horse water" and discharged. Small water ground irrigation, dilute the poison. Fertilizer to grasp less fertilizer and many times, the first amount after a small amount, increase the ratio of phosphorus and potassium. Qi Miao Shi after the "break" rooted fertilizer, the two leaves after the early application of "weaning fertilizer." Seedlings grow slowly, yellow leaves, and even rainy days, we must pay attention to fertilization.

2. Chemical control: optional 25% metalaxyl WP 800-1000 times or 65% dexcone 700 times wettable liquid or 30% WP 50-800 times, should be kept when spraying Thin water layer. It is also possible to fill more than 90% of copper sulfate 100-200g in the water inlet with a gauze bag and pour into the field with the water. When the cotton rot is serious, Putian should change the water for 2-3 times before spraying.