Pictures of rice diseases and insect pests control technology and rice disease control

1. Rice blast Rice blast, commonly known as "ghosts pinch the neck", is one of the three major diseases of rice. Seedling blight: the base of diseased seedlings turns brown. The upper part is yellowish brown or reddish brown and dies. When wet, there is often a gray-green mold layer on the surface of diseased seedlings. Leaf blast: the lesion is spindle-shaped. The outermost layer is yellow, the inner ring is brown, and the center is gray-white: there are brown necrosis lines extending outward at both ends of the lesion, which are long. Gray-green mold layer is produced on the back of the lesion. Ear and neck plague: occurs in the ear and neck. The affected part is brown or dark green. Early onset ear and neck often form "all white ears": late onset will not be rich in grains. The diseased ear often falls off from the neck, forming a hanging neck.

Prevention and control methods: ① seed disinfection: soaking seeds with 1% lime water; Strong chlorine essence disinfection. (2) Seed soaking with medicine: using 2% tricyclazole wettable powder, cleaning the seedlings according to the ratio of 50g: 25kg of water, spin-drying, soaking in the liquid medicine for 30s, taking out for 30min, and then planting. ③ Spraying control: once the disease center of leaf blast appears, spraying thiophanate methyl and thiophanate ethyl 1000- 1500 times in time; Fuji-1 can also be used. Generally, 900kg water is sprayed with 750 ml/hm2. No matter whether there are diseases in the field or not, 900kg water 1 time was sprayed with 20% tricyclazole wettable powder 1.5 kg/hm2 at the interval of rice heading. When ear neck blast was found after heading, 900kg Fuji 1No. 1500 ml/hm2 water was sprayed.

Second, rice sheath blight

Sheath blight, commonly known as pedicel, is grayish white in the middle of the lesion. The edge is dark brown, and often several lesions are interconnected to form large moire spots. In rainy and humid weather, the disease will grow white or gray spider silk mycelium. Later, it gradually formed a white fluffy block and finally became a brown sclerotia.

Prevention and control methods: ① remove the source of bacteria, salvage "wave residue", eradicate weeds at the edge of the field, and return the disease-free straw to the field; ② Rational fertilization and irrigation; ③ timely spraying: use 65,438+0% (65,438+0,000 units) jinggangmycin wettable powder 7.5 kg/hm2 or 2% jinggangmycin 65,438+0.65,438+0.25 kg/hm2, or 50% carbendazim wettable powder 65,438+0. You can also use plant ash 225-300kg/hm2 to soak in water 1500kg for one day and night, and filter and spray; Or directly sprayed with plant ash 375-525 kg/hm2.

Third, the rice stalk fly

Larvae is milky white, which is harmful to human heart. After the seedlings were killed, the heart leaves appeared oval or long holes, which later developed into longitudinal cracks and the leaves were broken.

Control method: 900kg water spray 18% dimehypo 3.75 kg/hm2.

Four, rice stripe disease

It is mainly transmitted by Laodelphax striatellus. Usually, the heart leaves of diseased plants show intermittent yellow-green or yellow-white short stripes along the veins, and then they are combined into large pieces, and half or most of the diseased leaves turn yellow or yellow-white. After the disease of tall stalk varieties. The heart leaves are slender, curled into paper twists, and bent and drooped to form a "fake dead heart": the heart leaves are still normal after the onset of dwarf varieties. Early-growing plants die, while late-growing plants only have chlorosis spots on flag leaves or leaf sheaths. But neither poor heading nor abnormal heading is true. The tillers of diseased plants generally decreased.

Control methods: ① Select disease-resistant varieties. (2) cut off the source of the virus. The first is to eliminate the virus-borne Laodelphax striatellus before the spread of the disease. Second, it is necessary to stay away from insect sources such as wheat fields, vegetable fields and grassland wasteland, remove weeds around rice seedlings and fields in time, and reduce the parasitism of Laodelphax striatellus. ③ Strengthen fertilizer and water management. Base fertilizer should be applied well, instead of tillering fertilizer, ear fertilizer should be applied again, and microelements such as zinc, boron and manganese or rice sensitive elements should be applied during the rice growing period to promote the healthy growth of rice and improve the disease resistance. ④ Chemical control. Seed soaking with chemicals in advance to prevent; Before transplanting seedlings, apply "grain-sending medicine" once; If it is found that the occurrence rate of the whole field is below 3%, it should be controlled. Selection of chemicals: seeds can be soaked with 65438% imidacloprid wettable powder 500- 1000 times or 5% regent suspending agent 800- 1000 times. Or 5% Regent seed coating agent for seed dressing: 10% phenanthroline 300g/hm2+36% trichloroisocyanuric acid 375-450g/hm2 can prevent virus; 10% imidacloprid 450-750kg/hm2+3.95% can be used in the field. The medication time should be controlled from the peak of hatching eggs of the second and third generations of Laodelphax striatellus to the peak of young nymphs.

Verb (abbreviation of verb) rice leaf roller

Rice leaf roller is also called leaf roller. The main migration period is generally from late May to mid-June, the peak of spawning is in mid-June, and the peak of damage is from late June to late July.

Larvae do harm, and the larvae spin silk to roll rice leaves into a tube and feed on mesophyll, forming white stripes. Being a victim is serious. The rice leaves have withered and turned white.

Control method: The best effect should be achieved when the larvae are in the whole incubation period. Generally, the annual defense for the third generation is around June 20th. It can be controlled by dimehypo (cheap to control borers) and dimehypo.

Six, rice planthopper

Rice planthopper is commonly known as "grasshopper". In the affected fields, rice leaves turn yellow and tillers decrease. In severe cases, rice leaves "fall into the pond" and die. Nilaparvata lugens mainly harms booting stage to maturity stage. When it is seriously damaged, the base of the rice cluster turns dark brown, and the whole plant gradually dies. The damaged field is often "Don Juan". In severe cases, the whole site is yellow and shaped like a fire.

Control method: When there are more than 50 plants in the field, two kinds of rice planthoppers should be controlled. The effective drugs are Chen Gong, Pushiling and Yechan Powder.

Seven, boring bugs

There are three kinds of stem borers: Chilo suppressalis, Chilo suppressalis and Chilo suppressalis.

All three species feed on larvae. At different growth stages of rice, the damaged plants can form dead heart, dead sheath, insect-damaged plants, dead pregnant ears and white ears. Chilo suppressalis larvae are reddish brown: Chilo suppressalis larvae are dark brown with five longitudinal stripes on the back: Chilo suppressalis larvae are yellow-green.

Prevention and control methods: agricultural prevention and control are the main ones, supplemented by chemical prevention and control. It is advocated to cut rice with mud, remove weeds from fields and ditches, and irrigate ploughed green manure fields and rape fields as soon as possible. Kill worms. 25% insecticidal powder 15.0-22.5 kg/hm2 can be mixed with fine soil, or 900kg water can be sprayed with 3.75 kg/hm2 of 25% insecticidal agent.

Eight, rice thrips

Rice thrips are small, with dark brown adults, wings and fast crawling. Life is divided into three stages: egg, nymph and adult. Nymphs are similar to adults, pale yellow, very small and wingless, and often roll at the tip of rice leaves and suck the juice of rice leaves. The damaged rice leaves are dehydrated and curled, the rice seedlings turn yellow, there are a little white spots on the rice leaves, and the heart leaves shrink, which looks like a fire from a distance. Rice thrips gather when flowers bloom.

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

(Author: 16435 1 Aihui District Rural Economic and Technical Service Center, Heihe City, Heilongjiang Province)