Study On The Causes And Sustainable Control Methods Against Brown Plant Hoppers In Single Season Rice System In Taizhou Area

As the succession of crop system, the lacking of resistant rice variety, the favorite climate conditions, and the resistance to Bichonglin, the rice Brown Plant Hopper (BPH) outbreaks frequently recently. The damage caused by BPH is the major thread for the yield of the single season rice system. Meanwhile, the rice quality is also largely reduced in terms of insecticide contamination. Subsequently, BPH becomes the major factor reducing the rice yield, the rice ecosystem function, and the quality of rice products. Aimed to figure out the major factors causing rice reduction in Taizhou area and searching for sustainable and economic control methods against BPH, various statistical approaches were applied in focused on the historical data and field researches. There were some important outcomes from the project called the mechanisms of BPH outbreaks in Taizhou area and its sustainable control method presented as follows:(1) The dynamic of BPH on single season rice system in Taizhou area was investigated. BPH population densities were increased when infested at the tillering and booting rice stages. But its relative population density was reduced after the late October as the result of increasing of the numbers of tillers. However, the increased infected numbers of BPH at the milking stage did not result similar pattern. These results provide the vital information for controlling the BPH in Taizhou area.(2) The major factors leading outbreaks of BPH in Taizhou were invasitgated. The immigration and allocation of BPH in Taizhou area, the resistance levels of BPH, the different cultural systems, rice varieties, and nitrogen levels effected on BPH were investigated. These results also provided scientific bases on the control method in Taizhou area.(3) The spatial distribution pattern and sampling methods on BPH in field condition were investigated. The methods for predicting the dynamic of BPH in single season rice system were established. Thus, the precision of forecasting on BPH occurrence was improved.(4) In focusing on agricultural, ecological, physical, and emergency control approaches, an integrated control system was studied based on Taizhou environment. In single season rice system, rice varieties against BPH, strategies of controlling BPH, economic threshold, and some experiments and applications of new insecticides against BPH, were studied. These studies also provided direct evidences to guide the control actions of BPH in Taizhou area.