INFLUENCE OF ENVIRONMENTAL CONDITIONS ON TOMATO MOSAIC VIRUS DISEASE DEVELOPMENT UNDER NATURAL CONDITION

Abstract

Tomato (Lycopersicon esculentum L.) Karst crop in Pakistan is confronted with a number of biotic and environment stresses due to which crop yield remained far lower than the potential. Tomato mosaic virus (ToMV) has attained the status of the second biggest threat to tomato production after tomato yellow leaf curl virus. To handle this problem, a study was conducted in 2008-09 in which three lines/varieties (Money maker, VRI-5 and VRI-29) were sown for screening against ToMV.  Money maker, VRI-29 and VRI-5 indicated the HS (Highly Susceptible), S (Susceptible) and MS (Moderately Susceptible) disease response respectively. The disease response of these lines/varieties were correlated with the data of environmental factors (temperature, relative humidity, wind speed and rainfall). Disease severity of ToMV increased on these lines/varieties, with increase in temperature from 20 ºC to 31 ºC, as indicated by r values 0.91, 0.97 and 0.94 of linear regression analysis, respectively. There was negative correlation of relative humidity to ToMV disease development, as the relative humidity increase from 55 to 70 %, as indicated by r values 0.91, 0.89 and 0.75, respectively.