Efficacy of Mulches and Methyl Bromide Alternatives on Soilborne Pests and Weeds in Spring Tomato

摘要

Tomato ( Lycopersicon esculentum Mill.) field studies were conducted to determine the impact of mulch types combined with soil fumigants on spring tomato yields and on soilborne pests and weeds. Fumigants were: a) untreated control, b) methyl bromide + chloropicrin (67/33%, respectively) at a rate of 400 kg ha^-1, c) chloropicrin at 400 kg ha^-1 plus the herbicide pebulate at 4.5 kg ha^-1, d) 1,3-dichlopropene at 325 kg ha^-1 + chloropicrin at 67 kg ha^-1 (83/17%, respectively) plus pebulate at 4.5 kg ha^-1 and e) metam sodium at 485 kg ha^-1 plus pebulate at 4.5 kg ha^-1. Mulch types were either black low-density polyethylene film (0.038 mm thick) or black paper mulch. Results indicated that all fumigants with either mulch type had higher tomato yield and more effective soilborne disease and purple nutsedge ( Cyperus rotundus L.) control than the non-fumigated control. Paper mulch appeared to be a valuable alternative to control purple nutsedge with no fumigants and with low-volatility fumigants, such as metam sodium, whereas plastic mulch might retain high-volatility fumigants, such as methyl bromide, longer, thus increasing efficacy.