Abstract
Despite glyphosate (N-(phosphoneomethyl)glycine) not having a label for tomato (Lycopersicon esculentum Mill.), glyphosate-like injuries have been reported on this and other polyethylene-mulched vegetable crops. It is hypothesized that these injuries are the result of two possible situations: (1) contamination of other pesticides during the packaging process, where the same packing lines are used, or (2) inadequate multipurpose sprayer rinsing procedures. The objective of this study was to determine the tolerance level in which glyphosate does not detrimentally affect tomato growth and fruit weight. This bioassay was conducted in Bradenton, Florida, with six glyphosate concentrations (0, 25, 50, 100, 150, 200 mg·L[sup-]) applied to the foliage one day before transplanting. Total fruit yield was reduced by 52 and 77% with 25 and 50 mg·L[sup-] glyphosate applied to tomato plant foliage 1 day before transplanting, respectively, relative to the non-treated control.
