Influence of tomato genotypes in relation to time of planting against fruit infestation by Helicoverpa armigera (Hubner)

Abstract

The tomato fruit borer (Helicoverpa armigera) is an important pest of tomato and the only practical method to control this pest is use of persistent insecticide over the foliage and fruiting bodies, so as to kill the early instar larvae before they enter the fruit. As tomatoes are harvested at short intervals, application of insecticides film is both uneconomical and hazardous (Kashyap and Verma 1986). The recent trend of pest management is not to depend entirely on the use of insecticides, but use of such practices viz., use of resistant or tolerant varieties and manipulation of dates of planting, cause of fertilizer etc. By adjusting the time of planting, infestation by some of the pests can be prevented. It has been observed that planting before or after a certain date can disrupt a synchronised crop-pest association and enable the plant to escape damage from pest during a susceptible growth stage, and also peak egg laying period of a particular pest can be avoided. Thus, the present investigation was made to assess the extent of damage caused by H.armigera by adjusting time of planting and using resistant or tolerant cultivars.