Influence of weeds and onion thrips, Thrips tabaci (Thysanoptera: Thripidae), on onion bulb yield in Jordan

Abstract

Field experiments were conducted in two seasons to investigate the effects of weeds and onion thrips on onion bulb yield grown under irrigation. Treatments were combinations of three levels of weed infestation and two onion thrips infestation levels. Weed interference was found to severely reduce bulb yield, whereas reductions from onion thrips infestations were of lower magnitude. Hand weeding was more effective in weed control than a single oxyfluorfen application. No significant interactions were detected in this investigation between weeds and onion thrips infestations, which could be attributed to the strong preference of onion thrips towards the crop over the weeds. (C) 2000 Elsevier Science Ltd.