Beware of bacterial leaf streak in rice

Rice bacterial streak, referred to as bacterial streak disease, is a bacterial disease caused by Trichoderma flavum, and it is one of the plant quarantine pests in China. High temperature and high humidity are conducive to the disease, which coincides with rainstorm, hail or flood, resulting in a large number of leaf wounds, the disease is very easy to spread. The incidence of long-term irrigation in deep water, partial application and late application of nitrogen fertilizer was also more serious. The yield of those with mild disease can be reduced by about 10%, and that of seriously diseased fields can be reduced by 40% to 60%.

Damage characteristics: Rice bacterial leaf spot mainly affected the leaves, the disease spot initially showed dark green water-clear translucent spots, and then gradually spread along the leaf vein direction.

The expansion is limited by the veins of the leaves, and the disease spot is thin linear or short dotted linear, yellowish brown. When the field humidity is high, the disease surface has honey yellow bacteria pus overflow, showing dewdrop shape, dense and dense, the number is more and smaller than bacterial leaf blight, yellow gum-like particles after dry formation, such as dotted lines, not easy to fall off. When the disease is serious, the spots fuse into irregular yellow-brown to withered white patches, which are somewhat similar to bacterial blight in appearance, but many transparent strips can be seen in light observation. When the disease is serious, the leaves curl and the field shows a yellow-white color.

Prevention and control methods: the disease spreads quickly, once the disease is difficult to control by chemical control alone, comprehensive prevention and control should be taken.

① quarantine: strictly control the transfer of seeds from the disease area to prevent the expansion of the disease area. ② agricultural control: disease-resistant varieties are selected, and different varieties have different degrees of disease susceptibility and loss. Implement frequent irrigation in shallow water and sun up the fields at the right time. Avoid excessive and late application of nitrogen fertilizer. Properly increase the application of phosphorus and potassium fertilizer to improve plant resistance, prevent rice seedlings from greedy growth and induce diseases. ③ chemical control: after finding the central diseased plant, start spraying 20% Yekuning (Ye Qingshuang) wettable powder, 100g per mu, 50 liters of water. When the control effect of Yekuning is not obvious, the control effect can be obviously improved by mixing 4000 times of streptomycin sulfate or 2500 times of streptomycin sulfate or 2500 times of strong chlorine. For areas where the disease is common, the seeds should be soaked in clean water for 12 hours before sowing, soaked in 300 times 85% chlorine for 12 hours, picked up and washed, and then germinated and sowed. The seedlings were sprayed with strong chlorine once at the three-leaf stage and before pulling seedlings. The effect can reach more than 80% with 4% glue amine copper, 20% Ye Qing Shuang and potassium permanganate plus salt and water spray at heading stage.