The effects of crimson clover companion planting on eggplant crop growth, yield and insect feeding injury

Abstract

The effect of using crimson clover (CC) (Trifolium incarnatum L.) as a companion plant on crop growth, marketable yield and insect feeding injury was examined using Eggplant, Solanum melongena L. as the neighbouring cash crop. There were two subplot treatments, which included applications of organic insecticides and no insecticides. Planting eggplant directly into CC did not improve most eggplant growth variables and resulted in a yield reduction during year 1. During year 2, when the CC was strip-tilled prior to transplanting the eggplant, several eggplant growth variables were more strongly enhanced in CC than bare-ground (BG) habitats. Eggplant in CC plots suffered less damage by insect folivores but yields were similar among treatments. There were no benefits of using organic insecticides with respect to increased marketable yields in CC treatment plots, but there was an increase in marketable yield in sprayed compared with unsprayed BG subplots. If properly managed, CC may help protect eggplant from insect feeding injury; however, this may not cause an increase in marketable yield.