Insect Damage: Tomatoes
Insecticides are generally used on close to 100% of tomatoes grown in eastern states to prevent damage from a large number of species that would feed directly on the tomatoes- significantly lowering their value. A study of tomatoes in Virginia revealed that uncontrolled insects lowered marketable yield by 33%. Insecticide cost ($230/A) prevented losses of from $3000-$7000/A.
“Insect pest management is critical to successful tomato production in the Mid-Atlantic U.S. Important pests each year often include the tomato fruitworm (= corn earworm), thrips, stink bugs, aphids, and spider mites. Occasional pests also include armyworms, Colorado potato beetle, hornworms, cabbage looper, and leafminers. To control this complex of pests, insecticide usage is often intense on commercial farms. For instance, in Virginia, tomato growers make an average of 7 to 10 pesticide applications per crop.
Although IPM and biological control programs have been demonstrated, insecticides continue to be the chief management tool by which damaging insect pests can be controlled immediately and economically for conventional tomato producers. Because strict quality standards for produce coupled with high production costs are unlikely to change significantly, current and future tomato pest management strategies are likely to include an insecticide component.”
Author: Thomas P. Kuhar
Affiliation: Associate Professor – Vegetable Entomology, Virginia Tech
Title: Update on insect pest management for tomatoes
Source: 2011 Proceedings 56th New Jersey Annual Vegetable Meeting. January 11-13, 2011. Available at: http://njveg.rutgers.edu/assets/pdfs/2011-56th-NJ-Annual-Vegetable-Meeting-Proceedings.pdf
Fumigated and Non-Fumigated
The disease known as cylindrocladium black rot (CBR) grows best in cool soils and is a major problem in the Virginia and North Carolina peanut regions. Entire pods may turn black and rot. The fungus may survive several years in the soil. Disease incidences in excess of 80% have occurred. The soil fumigant, metam sodium applied 8-10 inches below rows at least two weeks prior to planting has been the standard recommendation for control of CBR since 1985. Recently, the USEPA conducted a study of the value of metam sodium for peanuts and concluded that…
“Thus, the main benefit of metam sodium is that it permits cultivation of peanuts that would otherwise not be economically viable. …a large proportion of peanut acreage in the North Carolina-Virginia region depends on metam sodium simply to make production economically viable.”
Authors: A. Chiri, and T. J. Wyatt
Affiliations: EPA, Office of Pesticide Programs, Biological and Economic Analysis Division.
Title: Assessment of the Benefits of Soil Fumigation with Metam Sodium in Peanut Production.
Publication: U.S. EPA. (2007). Assessment of the benefits of soil fumigation with metam sodium in peanut production (DP#337490). Available at http://www.regulations.gov/#!home
Thrips have many hosts, including grasses, grains and alfalfa. Large populations often develop on these hosts and fly into cotton fields when the cotton seedlings are developing. Thrips feeding causes severe deformation and stunting of the developing cotton leaves. The Upper Southeast cotton region (Virginia and North Carolina) could be designated “Thrips Central” for the Cotton Belt. Jack Bacheler, a North Carolina Extension Entomologist, explains…
“With the exceptionally warm winter and good moisture levels, at this point it looks like thrips flights into cotton should be both large and early this year. … Our region has earned the distinction of having the highest levels of thrips and greatest potential damage to seedling cotton of anywhere in the U.S. In some tests, with the help of a microscope, we sometimes count as many as 200 to 500 thrips per 5 seedlings! That’s a “ton” of thrips, especially if seedlings are unprotected. So it’s probably not a surprise that Virginia and North Carolina have the highest ratio of surrounding host vegetation to small average cotton field size.”
“Over the past eight years, more than 85 percent of our cotton acreage has been over-sprayed [i.e. sprayed over] following a seed treatment. With the potential for thrips damage lasting up to 5 or 6 weeks after planting and seed treatments varying from about 2 to 3 weeks in their activity, a high percentage of foliar follow-up treatments for thrips is not surprising.”
Author: Jack Bacheler
Affiliation: North Carolina Extension Entomologist
Title: Heavy thrips populations anticipated.
Publication: Southeast Farm Press, April 18, 2012. Available: http://connection.ebscohost.com/c/articles/76291692/thrips-pressure-heavy-mississippi-cotton