Stripe leaf blight is a serious disease that occurs in rice. Timely pesticide control to reduce losses.
Stripe leaf blight is a viral disease transmitted by Laodelphax striatellus. The disease has the characteristics of intermittent outbreaks. It mainly depends on the poisoning rate of the Laodelphax striatellus. After a certain period of accumulation, the gray planthopper once formed a strong poison. The group will trigger a disease epidemic for several years. In recent years, it is in the epidemic period of the disease. If it is not controlled, it may cause 30%~50% loss, and even the harvest will be destroyed. Now it is a crucial period to prevent and cure the disease.
The typical symptoms of rice stripe disease are: chlorotic yellow and white spots appear at the base of the heart at the seedling stage, and then expand into yellow stripes parallel to the veins, and the stripes remain green. Different varieties have different performances. The heart of the indica, japonica and high-stalked japonica rice is yellow-white, soft, curly and drooping, and has a heart-like shape. The dwarf japonica rice is not in a heart-like shape, and there are yellow-green interlaced streaks, and the tiller is reduced. The diseased plants die early; the pupa stage begins with chlorotic macula at the base of the next leaf of the heart, and then expands to form irregular yellow-white streaks. The leaves are not obvious; after the jointing, only the yellow-green stripes appear in the lower part of the flag leaf, the heading is deformed, and the fruiting is reduced. It can be seen that the earlier the onset, the more serious the condition and the greater the loss.
There are two special points for prevention and treatment: First, because the virus can only be transmitted by the gray planthopper, "pest control and disease prevention" and "cutting off the poison source" are the basic guidelines for prevention and control, and the first, second and third generations of the adult fly thistle Putian and Honda formed the characteristics of three peaks of disease, and it is necessary to carry out multiple prevention and control in stages to be effective. Second, according to the law of the earlier infection of the virus and the more serious the disease, the "treatment of the field of Baotian Datian, the pre-treatment period of the pre-treatment period" was adopted. Prevention strategy.
Chemical control generally begins in mid-June, focusing on the prevention and control of the seedling stage of the gray planthopper. The recommended agents are: imidacloprid (Dagongchen), pymetrozine, fipronil (Ritengite), chlorpyrifos or a mixture thereof. preparation.
The prevention and control of Daejeon spray should be carried out in the tillering stage of rice, and the selected agents are: imidacloprid, chlorpyrifos (long-acting sustained-release agent), isoprocarb (leaf sputum), and thiamethoxam, buprofezin, avermectin, etc. . Pesticide nets recommend rotating drugs to delay the development of resistance to planthoppers; choose pyridone, fipronil, thiamethoxam, imidacloprid, etc. with better persistence, and better chlorpyrifos, isoprocarb, and chlorpyrifos. Dichlorvos and other mixed use to improve the control effect.
In addition, ploughing and irrigating, clearing weeds in the field and on the edge of the field, on the edge of the ditch, on the side of the road, intensively raising and keeping away from wheat and corn fields, can reduce the source of the virus; appropriately delay the sowing date, plant resistant varieties, and increase phosphorus and potassium fertilizers. Strengthening management is also a necessary comprehensive prevention and control measure.
In addition, China Pesticide Network recommends the use of imidacloprid seed dressing, the initial stage of the disease can be sprayed with chlorobromoisocyanuric acid (sterilization, sterilization), Ningnanmycin (bacteria gram), has the effect of inhibiting the virus and alleviating symptoms.
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