| 【Objective】The study was to explore the causes of rice straight head in Mianyang City and the corresponding control measures.【Method】By means of investigation and field test, the incidences of rice straight head under different herbicide treatments were compared, and the types and contents of heavy metals in soil and rice plant were measured to preliminarily determine the causes of rice straight head in Mianyang City. The control measures were explored by analyzing the incidences of rice straight head under different control methods.【Result】Herbicide application was not the cause of rice straight head, but excessive herbicide application could significantly reduce rice yield. The content of As in the soil layer of 0-50 cm in diseased field was 2.3-5.6 mg/kg higher than that in non-diseased field. The content of As in diseased plants was 0.03-0.20 mg/kg higher than that in non-diseased plants. Compared with the control, sulphur application during wheat season and lime application during rice season could reduce the incidence rate of rice straight head by 20.74%. The planting of japonica rice varieties in the fields could significantly reduce the incidence rate of susceptible rice straight head compared with that of indica rice varieties.【Conclusion】The occurrence of rice straight head in Mianyang City was related to the high content of As, Cd and Cu in soil. The four herbicides, bensulfuron-methyl and acetochlor, pyrazosulfuron, quinclorac and penoxsulam, were not the causes of rice straight head. Under the conditions of wheat-rice rotation and full straw returning, sulfur application in wheat season and lime application in rice season can prevent and control the disease effectively. |
