Effect of abiotic factors on the seasonal incidence of fruit borer, Helicoverpa armigera (Hub.) on tomato with and without marigold as a trap crop

Abstract

Field experiment was conducted to study the seasonal incidence of tomato fruit borer, H. armigera (Hub.) on tomato with and without marigold as a trap crop. The incidence of H. armigera on tomato without marigold as a trap crop was first noticed in the first week of February. The pest touched the peak with a mean of 4.40 larvae / plants during third week of March. Similarly, the incidence of H. armigera on tomato with marigold as a trap crop was first noticed in the fourth week of January. The pest touched the peak with a mean of 1.20 larvae/plant during third week of March. The correlation between fruit borer population and mean atmospheric temperature was positive and significant in with and without marigold (r= 0.633 and 0.677, respectively). The significantly positive correlation were found between H. armigera larvae and damaged fruits in tomato with and without marigold (r = 0.878 and 0.929, respectively).