Evaluation of companion crops for thrips (Thysanoptera: Thripidae) management on French bean Phaseolus vulgaris (Fabaceae)

Six companion crops, i.e. Tagetes erecta, Daucus carota L., Coriandrum sativum L., Brassica oleraceae L. var. acephala, Capsicum annuum L. and Zea mays L., were evaluated for their efficacy in suppressing field populations of Frankliniella occidentalis (Pergande) and Megalurothrips sjostedti Trybom on French bean Phaseolus vulgaris L. Each companion crop was interplanted with French beans in a 3×10 m plot and replicated three times in a completely randomized block design. The thrips populations on French bean flowers in experimental plots were compared with those on beans treated with two insecticides: L-cyhalothrin (Karate 1.75% EC) and methiocarb (Mesurol 500 SC) or untreated (control). Coriandrum sativum, Z. mays and T. erecta are recommended as companion crops for intercropping with French beans to reduce populations of thrips and hence minimize the use of chemical insecticides on this crop.