How to control rice false smut? Detailed explanation of its occurrence characteristics and control techniques
I. Occurrence characteristics. Rice false smut occurs only on the panicle, generally from the flowering stage to the milk-ripe stage of rice. In infected grains, the pathogen grows inside the glumes, forming false smut about 1 cm in diameter that replaces the grain. The optimum temperature for the germination and development of the rice false smut pathogen is 25-30°C; above 34°C or below 12...
I. Occurrence characteristics
Rice false smut occurs only on the panicle, generally from the flowering stage to the milk-ripe stage of rice. In infected grains, the pathogen grows inside the glumes, forming false smut about 1 cm in diameter that replaces the grain. The optimum temperature for the germination and development of the rice false smut pathogen is 25-30°C; above 34°C or below 12°C the pathogen cannot grow. The rice false smut pathogen can infect the flowers and young glumes of rice. The main period of infection is the middle booting stage of rice; after the boot stage and flowering, infection rarely occurs. From the late booting stage to the heading stage of rice, if conditions of high humidity, suitable temperature and a small day-night temperature difference are encountered, this is extremely favorable for the occurrence and spread of the disease, making it a typical climate-type disease. At the same time, there are obvious differences in resistance among varieties, and the occurrence of the disease is positively correlated with unreasonable nitrogen fertilizer application. Fields with excessive nitrogen fertilizer and tender green growth in the middle and late stages of rice, and low-lying fields with high humidity, suffer severe disease.
II. Control techniques
1. Agricultural control: Select relatively resistant varieties, plant appropriately sparsely, and when using the seedling-throwing cultivation method be sure to throw sparsely to cultivate strong productive panicles; fertilize reasonably, control the amount of nitrogen fertilizer, increase the application of phosphorus and potassium fertilizers, apply topdressing early to promote early development, control the amount of panicle fertilizer, change the traditional fertilization method to a balanced promotion method so that the rice plants naturally turn yellow in the later stage and the disease resistance of the rice plant is enhanced; irrigate reasonably, and drain and dry the field at the appropriate time and to an appropriate degree.
2. Chemical control: The appropriate time for application is 10-15 days after the heading of rice (before the rice forms the middle boot and before preventing panicle blast). Per mu, spray 60 grams of 20% validamycin, or 15 milliliters of validamycin-pyrimidine, or 150-200 grams of 16% validamycin-ketone-tricyclazole, mixed with 50-60 kg of water for spray control.