RESEARCH WITH MICRO COMPUTER ON MEDIUM AND LONG TERM OCCURRENCE FORECAST OF RICE STEM BORER IN SOUTH FUJIAN

The rice stem borer, Tryporyza incertulas Walker, is a major rice pest in Fujian.It usually makes a yield loss of 5-10%.Since it is polyvoltine insect, it multiplies four to five generations each year in south Fujian. And the occurring time and quantity in various generations change with seasons and places.In the research, according to the classical demand on the forecast factors for the rice stem borer, 68-82 factors of the occurring time and 83-94 facetrs of the occurring quantity were selected as the parameters of forecast equation.Then the computer IBM-pc/xt was used for polyre gression to build up the forecast equation as follows: yx=a0x0+a1x1+…+anxn(yx Where yx = is the occurring time or quantity, an the coefficient, and Xn the forecast factor. Simultaneously IPM experience of various forecast stations was programmed and put into computer, as reference data on controlling the pest.Two years of practice proved that the rate of exact forecast was 57.14% and the rate of conformable forecast was 92.9% within the range of allowable error.