Field distribution pattern of diseased plant of pepper powdery mildew

Pepper powdery mildew is an important disease in pepper growing area, caused by Oidium taurica(L佴v.)E.S. Salman. By aggregate indices and Lwao M*-m regression, 6 spatial distribution patterns and the relationship between different disease severity and spatial distribution, were studied in this research. The result showed that the diseased plants in all survey plots were aggregated distribution under vertical distribution during the occurrence period of pepper powdery mildew, the leaves in central and lower part of plant were horizontal distribution, indicating that three plots were aggregated distribution, and other seven plots were evenly distributed; the relationship of disease index (DI) and frequency of inspection of the vertical distribution type, showed that no matter what value of the DI, the distribution pattern in the vertical direction were aggregated distribution, expressed as point and space occurrence of the disease. The relationship of DI and frequency of inspection of the leaves of lower part of plant with horizontal distribution type, with DI of 0.1827 to 0.5160, was the negative binomial distribution, Neyman Distribution A, the distribution-type was aggregated distribution, expressed as point and space occurrence of the disease; when 0.5160