1Department of Plant Pathology, Orissa University of Agriculture and Technology, Bhubaneswar, Odisha, India
2Department of Plant Pathology, Bidhan Chandra Krishi Viswavdyalaya, Nadia, West Bengal, India
*E-mail: poly.saha@gmail.com
Online published on 13 June, 2013.
Two experiments were conducted to assess the crop loss in tomato in relation to disease severity due to early blight (Alternaria solani Ell. and Mart) in the year 2007–08 and 2008–09 in the Gangetic plains of West Bengal. A linear regression equation was developed to find out the relation between the two and the prediction equation so developed revealed that loss in yield was 0.75 to 0.77 t/ha for every 1% increase in disease severity for the two consecutive years and also in pooled mean (0.76 t/ha). In the second experiment, evaluation of four promising tomato genotypes Patharkuchi (susceptible), Himsona (tolerant), Ajeet 11 and Arka Bikas (moderately under both protected and unprotected conditions for two consecutive years showed that fruit loss due to early blight was highest in Ajeet-11 (47.60%) and Patharkuchi (44.40%), while lowest loss was recorded in Himsona (42.35% and 39.52%). Highest yield loss was recorded in Arka Bikas (45.14%) and Himsona (48.85%) and minimum in Patharkuchi (32.75% and 39.09%,), respectively.
Tomato, early blight, Alternaria solani, disease severity, yield loss, linear regression, prediction equation
