In 1994, the U.S. Department of Agriculture established the Integrated Pest Management Initiative. Its goal was to foster the adoption of IPM practices on 75 percent of U.S.-planted cropland by 2000. During those six years, the use of IPM practices increased from around 40 percent to nearly 70 percent, yet pesticide use (in terms of weight per unit of area) increased slightly.
Florida fresh market tomato growers were among the IPM adopters. They are committed to IPM principles and practices.
The USDA has collected and published pesticide use data on select Florida crops, including fresh market tomatoes, every other year from 1992 through 2004. By examining this data, it is evident that the implementation of IPM principles by Florida tomato growers, working in conjunction with Extension agents and professionals, has led to a decline in the use of restricted use and “Danger”-labeled pesticides. The lack of commitment to IPM, on the other hand, can lead to crop loss and failure.
An in-depth look at the data
The insecticides endosulfan, esfenvalerate, methamidophos, methomyl and permethrin, the herbicide paraquat, and the fumigants chloropicrin and methyl bromide represent more than 95 percent of the restricted and “Danger”-labeled pesticides used in Florida’s fresh market tomato production. No fungicides used in Florida fresh market tomatoes are classified as restricted use.
From Table 1, it is apparent that use reductions of between 74 percent and 79 percent (in comparison to the peak year of 1994) have occurred since 1998, with the last year of data reflecting a 75 percent reduction in restricted or “Danger”-labeled insecticide use in Florida tomato production.
A similar but less dramatic reduction has occurred in fumigant use. In this case, the impetus for reduction in use has come mainly from the methyl bromide phaseout that is occurring under the Montreal Protocol on Substances that Deplete the Ozone Layer. This trend is mainly due to the reduction in rate, rather than a reduction in use, because all fresh market tomato acreage is fumigated.
Use reductions of between 17 percent and 26 percent (in comparison to the peak year of 2000) have occurred since 2002. The use of methyl bromide will continue to shrink, until it is completely phased out as an agricultural pesticide. However, its use may well be supplanted by methyl iodide, which would likely carry the restricted use status and “Danger” labeling.
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.