Anthracnose of guava caused by Colletotrichum gloeosporioides is one of major constraints in successful cultivation of guava. The disease produces brown to dark spots on the fruits affecting their quality. The weather variables such as temperature, relative humidity, rainfall and number of rainy days greatly influence the development of disease. In order to ascertain the impact of weather parameters on disease development, observations on disease severity were recorded during 2004 and 2005 in the orchard. It was observed that disease initiated in the field during the second week of July and per cent disease index reached maximum in September. The mean maximum and minimum atmospheric temperatures were negatively correlated with the disease development during the critical period (from 1st July to 9th October) having ‘r’ values of -0.762 and -0.827, respectively during 2004 but in the year 2005, the correlation was positive (0.258) with the mean maximum temperature, however, the mean minimum temperature exhibited a negative correlation (r= – 0.621). A significant correlation between disease severity and relative humidity was also recorded during both the years of observations. Per cent disease index also exhibited a positive correlation between rainfall as well as number of rainy days during 2004.
Anthracnose, guava, Colletotrichum gloeosporioides, weather parameters
