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Field and Forage Crops |
As is typically the case with cotton insects, predictions about their upcoming severity -- even up to and beyond the time of planting -- are often little better than random guesses. Overwintering pest levels and beneficial insect survival, the amount and quality of nearby crop and weed hosts, cotton crop development, and most importantly, weather just prior to and during the growing season, all affect insect levels. As is the case with insect pests of other row crops, we also deal with pests that undergo several generations on other hosts before playing their hand on cotton. This makes early predictions even more difficult. Some observations for 2005, however, may be order.
Thrips have been an annual problem for cotton growers here for decades. Perhaps due to our cooler seedling grow-off conditions and the high amount of surrounding thrips host vegetation compared with our average field size, thrips levels are almost always higher and more damaging in the Carolinas and Virginia than elsewhere in the Cotton Belt. The odds appear to favor thrips being a significant seedling pest again in 2005, and a preventative approach (seed treatment or an at-planting insecticide) is still recommended except on ultra narrow row cotton where the cost of an at-planting insecticide or seed treatment may be prohibitive.
The odds are that stink bugs will probably enjoy a banner year on Bollgard cotton in some regions of the state in 2005. Stink bug damage to bolls was high in both 2000 and 2001, although stink bugs gave most of our producers a break in 2002 and in 2003. In 2004, both green and brown stink bugs arrived early and at very high levels throughout most of the state. The 2004 level of damaged bolls in both conventional and in Bollgard cotton was without precedent in 2004 (four-fold higher than in any year since our fall damage boll survey began in 1985). This is a pest we'll be covering in greater detail throughout the 2005 growing season.
Bollworm moth levels have seesawed up and down for the past 8 years in North Carolina, although both 2003 and 2004 were relatively high years. In 2004, late season tobacco budworms caused headaches on conventional cotton for a number of producers accustomed to dealing with bollworms only. This infusion of tobacco budworms into the major bollworm moth flights varies greatly from one year to the next, and, though typically not much of a problem, years like 2004 can result in significant damage. Egg diagnostic kits, used to separate bollworms from budworms at the egg stage, are probably the most reliable indicator potential budworm problems. A good way to get an early indication of the timing and intensity of upcoming major bollworm moth flights is to view light trap counts on the Cotton Insect Corner web site beginning in early July.
Over the coming crop season, weather will essentially determine the timing and level of our potential insect problems, not to mention the impact of weather on lint yield and quality. I, let alone meteorologists, have difficulty in predicting weather patterns (and their impact) more than about a week in advance. Fortunately, sound insect and plant monitoring and rapid responses to thresholds should play a major role in making the best of what nature has in store for us.
Upcoming cotton insect scouting schools will be posted beginning mid May in the North Carolina Pest News and on the Cotton Insect Corner web site.
The cotton insect hotline Teletip tapes will begin next week. They can be accessed by calling 1-800-663-7301, then by pressing "4" for cotton insect updates. These messages will be updated each Wednesday. Briefer MP3 sound tracks can be found at the Cotton Insect Corner web site, beginning May 1, at: http://ipm.ncsu.edu/cotton/insectcorner/radio/index.html.
There are several resources available to farmers, agents, and consultants to monitor the progress of rust in the United States. Electronic resources are currently in place that will aid in the decision making process as to whether it is necessary to apply fungicides for management of soybean rust. The U. S. Department of Agriculture has a public web site (http://www.usda.gov/soybeanrust/) that soybean managers can access. Among the useful information at this web site is recent news about Asiatic soybean rust, information on fungicides, management practices, and most importantly a series of maps that show the location(s) of current rust findings so that the progress of disease can be tracked. The maps also show which areas have been scouted and areas where no rust has been found are marked in green. The web site will rely on information from active scouting of locations where rust is likely to have begun, sentinel plots that were planted early in order to detect rust, and from positive samples that come from diagnostic labs. Later in the season counties will be color coded as to a recommendation to spray preventively, curatively or not to spray. A second web site is the Soybean Rust Forecast Center located at North Carolina State University. This web site is updated three times weekly and shows where rust spores from locations at which soybean rust has been found are likely to travel over a given time period. Soon, the forecast will contain information along the trajectory path concerning the likely hood of infection. Old forecasts are archived at this web site and can be accessed as well as links to other useful web sites. From the rust forecast site the Tobacco Blue Mold and Cucurbit Downey Mildew web sites can also be accessed.
The book Foliar Fungicides for Management of Soybean Rust, will be available from County Cooperative Extension offices and is now on the Web at: http://www.oardc.ohio-state.edu/SoyRust/index.htm. This book is an excellent resource for soybean growers and pesticide applicators should soybean rust become a problem in 2005. It deals with a number of topics related to special requirements for fungicide application.
Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age or disability. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.
Last modified on April 18, 2005 by Stephen J. Toth, Jr.