Influence of environmental factors on the incidence of twig blight in sweet orange

摘要

The progress of twig blight in sweet orange under field conditions was studied from 1999 to 2005 using multiple regression analysis. Minimum temperature, morning and evening relative humidity, number of rainy days and previous level of disease had positive correlation with twig blight incidence, while maximum temperature and wind speed were negatively correlated. Multiple regression equation was derived for predicting the twig blight incidence. The joint influence of biotic and abiotic factors accounted for 61 % variation in the disease incidence.Temperature, relative humidity and previous level of disease were found to be the important variables influencing the disease.