Common Rice Diseases and insect pests and their Control methods

Rice thrips: Rice thrips are very small, adults are dark brown, winged, and crawl very fast. Life is divided into three stages: egg, nymph and adult. Similar to adults, nymphs are yellowish, small, wingless, often curled at the tip of rice leaves, and suck up the sap of rice leaves. The killed rice leaves lose water and curl, the rice seedlings turn yellow, there are dots of white spots on the rice leaves, and the heart leaves shrink, which looks like burning from a distance. Rice thrips gather during flowering

Prevention and control methods: because the rice thrips are very small, in general, it is not easy to attract people's attention, but only when the rice is seriously harmful and causes a large number of rolled leaves. Therefore, it is necessary to check in time to eliminate the rice thrips in the larval stage. Use 40% dimethoate emulsion 1500-2000 times per mu, and keep the water layer after application in seedling fields and fields. After the control of rice thrips, quick-acting fertilizer should be applied to promote the growth of seedlings and tillers.

2. Rice planthopper: Brown gray planthopper and back planthopper are the most harmful to rice planthopper. The rice planthopper generally hides in the leaf sheath and stem tissue of the lower part of the rice plant in the middle of the rice field, sucking the sap of the rice stem, and irregular long brown spots appear in the damaged part of the rice plant. in severe cases, the base of the rice plant turns dark brown. Due to the destruction of stem tissue, nutrients can not rise, rice plants gradually withered and withered, or lodging. After heading, the lower rice stem is senescent, and the rice planthopper transfers the upper part to absorb the tender panicle neck, so that the rice grain becomes empty shell or semi-full grain. At the same time, gray planthopper can spread rice virus disease.

Prevention and control methods: 1, dripping oil to kill insects. Drop 400 grams of waste diesel oil or waste engine oil per mu, keep a shallow water layer of 20 cm in the field, manually drive out insects, insects fall into the water and touch the oil and die. Change clear water after treatment, do not use this method after booting. 2. Spread poisonous soil. Sprinkle with 1.5 kg dimethoate powder and 2 kg moist fine soil per mu. 3. Spray with 40% dimethoate emulsion 0.5 kg plus water 800-1000 kg.

Rice bract worm: Rice bract worm, also known as curly leaf worm, often occurs once a few years, resulting in a substantial reduction in rice production. The adults are reddish brown butterflies, and the larvae harm rice. After the rice leaves are killed, they are broken and broken. In serious cases, only veins are left, and the rice bushes are like brushing pot brooms. Especially after the rice was killed at the booting stage, the larvae silked the rice leaves together to form the curl of the rice ear and could not produce the ear, which affected the yield.

Prevention and control methods: 1. Use 2.5% trichlorfon powder per mu to spray 2kg powder or methyl six powder 1kg to add fine soil and 10kg poisonous soil. 2. Spray with 150 grams of 90% crystal trichlorfon and 80 kilograms of water.

4. Rice leaf roller: the larvae begin to spin silk in the heart leaves of rice, rolling both sides of the leaves into tubular bracts, and the insects hide in the bracts to feed on the mesophyll and upper epidermis, and endanger them in the tender leaf sheaths after heading. In severe cases, the rolled leaves only have transparent and whitish epidermis, and the whole leaves die.

Control method: spray with 25% 223 emulsion 250 times and 90% trichlorfon 1000-1500 times. The control time should be controlled before the third instar of the larvae, and the effect of medication in the evening is the best. After prevention and treatment, the effect should be checked, and if the population density is the same as before, it should be treated again.