Epidemiological studies on some diseases of guava (Psidium guajava L.)
Sitansu Pan and N. K. Mishra
The role of weather factors, such as temperature, total rainfall, number of rainy days and relative humidity on the development of diseases like canker (Pestalotia psidii), anthracnose and die back (Colletotrichum gloeosporioides), stem canker and dry fruit rot (Botryodiplodia theobromae) and Phytophtora fruit rot (Phytophthora nicotianae var parasitica) of guava were analysed for predictive purpose from regression equations. The simple correlation coefficient matrix showed significantly positive correlation of canker severity with maximum relative humidity at 1% level whereas, anthracnose correlated well with minimum relative humidity, temperature and number of rainy days at 5% level. The negative correlation was obtained for stem canker and dry rot with all parameters at 1% significant level. In case of Phytophthora fruit rot, positive correlation was also recorded with all parameters, except maximum relative humidity. Keywords: Disease prediction model, weather parameters, Pestalotia psidii, Colletotrichum gloeosporioides, Botryodiplodia theobromae, Phytophthora nicotianae var parasitica.