Beware of Rice Disease after heading of late Rice

Rice blight, also known as glume blight, is not only a fungal disease, but also one of the common diseases in the later stage of late rice. The disease occurs only on grains, with brown dots on the grains at the beginning of the disease, and then gradually expands to most or all of the grains. The milder ones can still bear fruit, but the rice pine is easy to be broken, and the serious disease forms blighted grains, which affects the decrease of yield. When heading and blooming, in case of a storm, the grains rub against each other to cause wounds, which is conducive to the invasion of germs and the disease is more serious. Generally speaking, the disease is more serious in rice fields with partial application of nitrogen fertilizer and insufficient application of phosphorus and potassium fertilizer, and more in rice fields irrigated by cold soaking or irrigated with cold immersion water. The prevention and control of the disease is generally after heading, for seriously susceptible rice fields, copper sulfate 0.5 kg per mu, quicklime 0.5 kg, water 100 kg, Bordeaux solution spray 75 kg per mu. Or spraying 30kg water with 30ml of copper noble (27.12% basic copper sulfate suspension) after full heading of rice has a better preventive effect. Rice powdery mildew is one of the main diseases of late hybrid rice. The disease is a fungal disease, which overwinters with chlamydospores attached to the seeds. Under suitable conditions, the spores germinate. Although the spores can be invaded in the whole heading stage of rice, they are most likely to invade in the full flowering stage. At this time, the disease will be more serious if encountered with autumn wind and autumn rain. The disease is easy to occur in late rice fields with partial or late application of nitrogen fertilizer. After the occurrence of the disease, the field chemical control can choose 20% trimethoprim EC 1000-1500 times solution, 50 kg spray per mu, the control effect is more than 80%, or 40% methomyl glue suspension 200 grams, 50 kg spray on water. Secondly, 50% carbendazim wettable powder 500 times solution, or 40% methyl thiophanate sulfur suspension 400 times solution also has a better control effect. The false smut of rice was infected before and after heading of late hybrid rice and appeared on the grains of rice panicles at milking stage. the diseased grains per panicle were as few as 1-2 grains and more than 10 grains, and the damaged grains could not bear fruit. At first, the rice koji is very small, and then the outer glume is opened to reveal a light green lump, that is, the spore seat of the pathogen. The pathogen overwinters in seeds or soil and infects again in the second year. The optimum growth temperature of the pathogen is 26 ℃ ~ 28 ℃, so it is sunny and sunny with less rain, hot weather and more disease. The rice fields with partial or late application of nitrogen fertilizer were prone to disease in the rice fields with thick green leaves during heading, and there were differences in the degree of disease among different varieties. In order to control false smut of rice, we must pay attention to spraying 5-7 days before heading. If continuous rainy weather misses the suitable period of 5-7 days before the break, as long as the medicine is used before heading of late rice, it will also have a better control effect. The selected agents are: copper noble spray 30ml / mu of water each time, which can kill the bacteria in the bacterial mass on the diseased grains, make them dry and fall off when the weather is fine and dry, and greatly reduce the number of diseased granules in the field. In addition, 30% inoculation EC, 30% Jiarun EC and 30% Shimiao EC can be selected, all of which have good control effect. (source: farmers' Daily 2009-8-31)