Use of the only restricted herbicide — paraquat — in Florida-grown fresh market tomatoes also has decreased from the historic highs. In this case, use reduction is cost and IPM related. Glyphosate pricing was easing during the 1990s, and paraquat-resistant weeds, such as American black nightshade and goosegrass, were noted in several areas of the state.
Use reductions of paraquat between 31 percent and 87 percent (in comparison to the peak year of 1992) have occurred since 1998 in Florida fresh market tomato production.
Yielding positive results
The reduction in use of restricted and “Danger”-labeled pesticides lowers potential hazards for mixer/loader and application personnel, as well as harvest crews. It also could reduce the potential hazards for associated wildlife and watersheds.
A look at pesticide residue measures also shows the positive effect of using IPM. The USDA’s Pesticide Data Program has reported residues of pesticides in fresh market tomatoes yearly from 1996. Reduced spraying of restricted pesticides is reflected in a 50 percent decrease in methamidophos residues (from 0.016 PPM to 0.008 PPM) in fresh market tomatoes from 1997 to 2003. These values are far from the 1.0 PPM tolerance in tomatoes for methamidophos, demonstrating proper use of the insecticide when employed for pest control.
In addition, it is evident that more growers are adopting IMP because there has been an increased use of “reduced risk” pesticides, which are generally more selective than restricted or “Danger”-labeled pesticides. Insecticides such as spinosad and imidacloprid have been adopted by Florida fresh market tomato growers as early as the mid- to late-1990s. Data from 2004 have revealed use of other such materials, including indoxacarb, pymetrozine and pyriproxyfen. None of these insecticides are restricted or “Danger”-labeled when purchased individually in Florida.
It is important to note that these “reduced risk” products are always more expensive than older, off-patent materials. Extension agents and professionals have been essential in educating Florida tomato growers, so that costs using “reduced risk” materials are commensurate with previous costs.
Mark Mossler is the pesticide information specialist for the University of Florida/Institute of Food and Agricultural Sciences Pesticide Information Office, (352) 392-4721.