Abstract
For over 35 years, Florida tomato (Lycopersicum esculentum L.) growers have relied on methyl bromide for their soilborne pest, disease, and weed control problems. The use of methyl bromide as a soil fumigant is now being phased out under the Montreal Protocol. Yellow nutsedge (Cyperus esculentus L.) and purple nutsedge (Cyperus rotundus L.) are among the major weed control challenges in many tomato production systems. Since the leading alternative fumigants provide less than satisfactory control of nutsedge, Florida growers may have to consider the use of a preplant herbicide for control. EPTC (s-ethyl dipropylthiocarbamate) is an effective material that provides selective pre-emergent control of grasses, sedges, and many broadleaf weeds. Three years of small plot trials in Florida have shown that application of EPTC to the bed surface just prior to mulch application with a 14-day pre-transplant waiting period delivered excellent crop safety with very good nutsedge control. On-farm demonstration trials in Southwest Florida on tomato using EPTC applied to the bed and immediately covered with polyethylene fi lm also demonstrated excellent nutsedge control and had no apparent effect on the crop. Early indications are that EPTC may be an important tool in tomato weed management in the development of methyl bromide alternative strategies.
