Epidemiological Aspects of Grapevine Anthracnose in Northern Dry Zone of Karnataka

Epidemiological aspects of anthracnose of grapevine; a potentially important disease indicated that the pathogen Sphaceloma ampetinum (de Bary) Shear, survived in old grape stalks for more than 2 ½ years. Spore trapping indicated a polynomial curve of spore production throughout the year with the maximum spore numbers during September, corresponding to maximum disease incidence. The spore numbers and subsequent disease incidence exhibited a positive influence of rainfall and relative humidity, while temperature was negatively related and September-October period was highly conducive for disease development. A forecasting model D=-1.4+ 2.6RH2+2.0 S was developed.