There are many kinds of rice diseases and insect pests, which have become an important factor hindering the high yield of rice, this paper mainly introduces the common diseases and pests of rice and their prevention and control, and proposes corresponding control measures according to their reasons and characteristics.
<h1 class = "pgc-h-arrow-right" >1 rice blight</h1>
1.1 Symptoms. Rice blight is a fungal disease caused by the infestation of Therierium subtilis. The disease can occur from the seedling stage to the panicle stage of rice, and is most likely to occur before and after panicle extraction. At the beginning of the disease, oval dark green spots appear on the leaf sheaths of rice plants close to the water surface, like boiling water, the spots gradually expand, the middle is gray-green or light brown, and then become gray-white, and the edges of the spots are irregular and brown.
1.2 Prevention and control methods. The prevention and control of rice blight should be based on integrated agricultural control, supplemented by chemical control0 (1) comprehensive agricultural control: rational fertilization and irrigation. Pay attention to the steady application of nitrogen and phosphorus fertilizers, increase the application of potassium fertilizers, and supplement zinc fertilizers. To use sufficient base fertilizer, and to ensure panicle fertilizer, generally in the middle of the rice growth period as far as possible not to use nitrogen fertilizer. Rice irrigation generally adheres to the principle of "shallow before, sun in the middle, and wet after". (2) Chemical control: spray 75 kg per mu with 5% jinggangmycin 0.2-0.25 kg with water. or 50 grams of 15% rust rather wettable powder spray 50 to 70 kg of water. When dispensing the agent, to ensure the amount of water, be sure to spray to the middle or base of the rice plant. The pesticide use time should be appropriate, not too early, not too late, that is, the drug cannot be applied before the jointing period, and the drug cannot be applied after the panicle extraction period.
<h1 class= "pgc-h-arrow-right" >2 rice blast</h1>
2.1 Symptoms. Rice blast can occur throughout the growth period of rice, and according to the victimization period and location, it is called seedling plague, leaf blast, knot blast, ear neck plague, branch stem plague and grain blast. Seedling plague: Generally occurs before the three-leaf stage, the base of the diseased seedling becomes gray-black, and the leaves become light reddish brown, so that the whole seedling dies. Leaf blast: Occurs from the seedling stage to the panicle extraction stage, mainly on the leaves, but also on the leaf sheath. Panicle neck plague: Occurs on the ear neck, making the ear neck turn black-brown, and finally dry and decay. Early onset makes rice turn into white ears, and late onset makes the grain not full.
2.2 Control method o (1) Spray the dowry medicine once 2 to 3 days before transplanting, spray once the dowry medicine, spray 30 grams of 75% sanhuanwa wettable powder with 30 kg of water per mu; or wash and dry the seedlings and soak it in 20% of the sanhuanli wettable powder 750 times liquid for 1 minute to take out the pile, stuffy for half an hour, and then plant; (2) spray prevention: leaf plague: once the diseased leaf or pathogenesis center appears, timely use 75% of the tricyclic wettable powder 30 grams per mu, and mix it with 50 to 60 kg of water spray. In the rice panicle rupture period, regardless of whether the field plot is diseased or not, it should be controlled once per mu with 20% tricyclic wettable powder 100 grams of water spray. Panicle plague: Due to the stuffiness in the field in the late stage of rice growth, the amount of liquid medicine should be sufficient, the spray should be uniform, and the 20% three-ring mile wettable powder 100 grams mixed with water and 60 kg spray should be used per mu. After the panicle is found, the panicle neck plague should be sprayed with 100 ml of Fuji-1 with 50-60 kg of water.
<h1 class= "pgc-h-arrow-right" >3 rice seedling disease</h1>
3.1 Symptoms. Rice seedling disease is a fungal disease caused by the infestation of Fusarium bacterium in the unnatural state and the infestation of Fusarium cane. The disease can occur from the seedling stage to the panicle extraction stage. The diseased plant is long, thin, yellow, usually 3 to 10 cm taller than the healthy plant, which is very easy to identify. The basal nodes of the diseased plant often have inverted air roots and a layer of pink mold. The pathogen develops at a moderate temperature of about 25Y, and the seeds carry bacteria.
3.2 Prevention and control methods. The selection of disease-free seeds or the use of chemicals before sowing are the key measures for control. Seed treatment before sowing, can be used to soak seeds in warm soup, disinfection of agents and other ways to disinfect the seeds; remove the source of bacteria, find diseased plants in the rice field, timely remove the burial, and completely destroy them, so as not to cause pollution.
< h1 class= "pgc-h-arrow-right" > 4 blight</h1>
4.1 Symptoms. It generally occurs at the rice seedling stage, resulting in rice seedlings. Most of the diseased seedlings caused by standing blight are in the 2 to 3 leaf stage, the occurrence site is at the base of the seedlings, the leaves first stop spitting, and then the heart leaves wilt and curl, the whole plant gradually withers and yellows, and the base of the diseased seedlings has white, pink or gray-black molds.
4.2 Prevention and control methods. Blight can be prevented for 48 hours with 50% carbendazim 500 times liquid or 40% doflame powder or 50% fossom double soak, and 1:1:250 Bordeaux liquid spray at the onset of the disease.
<h1 class="pgc-h-arrow-right" >5 armyworms</h1>
The armyworm is a migratory pest that generally flies at a speed of 20 to 40 kilometers per hour. Mainly with the larvae to eat rice leaves to cause harm, with diurnal and nocturnal, cluster hazards, its hatching larvae hide in the heart of the rice plant, the leaf sheath bites the leaf flesh, so that the affected leaves leave some slender strips of film, 2 to 3 year old larvae increase the amount of food, the leaf bite into holes; 5 to 6 years old elderly larvae the amount of food surges, the leaves are eaten, only the leaf veins, stems, armyworm outbreaks, resulting in serious insect infestation losses. Prevention and control methods: (1) spray 50-60 kg per mu with 50% zinc thiophosphorus 0.1-0.15 kg with water; (2) 50 to 60 kg per mu with 80% dichlorvos; (3) spray 0.1-0.15 kg per mu with 2.5% enemy kill with water 50 to 60 kg.
< h1 class = "pgc-h-arrow-right" > 6 leafminer flies</h1>
From the beginning of rice seedling field film removal to the seedling planting stage is the main period of harm. The larvae submerge on the flesh of the leaves, causing the rice leaves to turn yellow, dry or decay, and in severe cases, the whole plant dies. After the rice seedlings, the plant has developed strongly, is no longer harmed, and flies to the weeds to breed. Prevention and control methods: (1) Timely removal of weeds in the paddy field, reasonable shallow irrigation, timely and early planting. (2) 1 to 2 days before planting, use 10% vizooth 3000 times liquid or 40% oxidation of Leguo 10. 0 times liquid, or 100 square meters of Amila 5 ~ 6 grams or 25% Aktai water dispersible granules 6 grams with water L5 liters spray control, seedbed prevention, half the effort. It can also be used to spray 30-40 ml with 1.5 liters of water or 3% insect emulsion of 30 ml per acre and 15 kg of water spray control.
<h1 class= "pgc-h-arrow-right" > 7 rice negative mud worms</h1>
Negative mud worms harm rice with larvae and adult insects, eating leaf flesh along the leaf veins, causing white longitudinal marks, and in the case of heavy disease, causing the whole leaves to turn white, resulting in rupture and decay, resulting in lack of seedlings. Even if the preservation activity will also cause the rice to ripen late, affecting the yield. Control methods: (1) Remove weeds in the wintering site of pests, and plant seedlings in a timely manner. (2) After planting, the insect situation of rice seedlings should be often investigated, and once adult insects are found to be harmful and have an aggravating trend, spraying should be carried out. The agent can be selected with a new generation of six-futin, 30 ml a bucket of water, spray prevention.