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Field and Forage Crops |
June tobacco budworms appear to about on or just a little behind schedule on cotton at this time, with scattered reports of eggs and small larvae from the southern and southeastern parts of the state. So far, very little in the way of treatable levels (that is 15 percent live budworms in terminals or 8 percent on squares) appear to be present. Georgia has apparently come through a moderate early budworm season. Remember that cotton almost always compensates well for moderate to sometimes significant squares loss from budworms, although delays in maturity should be avoided where possible with this cotton crop (that is already late). If insecticide treatment is needed on conventional (non-Bollgard) cotton, Tracer, Steward and Larvin are the materials of choice for budworms.
Although plants bugs are not often significant pests in pre-blooming cotton here, our abundant, rank spring growth has supported high levels of these pests. Sweeping around weedy field borders and along ditch banks can easily confirm this situation. Plant bugs will likely occur in higher numbers in squaring cotton than we have seen in several years. Georgia has been experiencing relatively high levels of plant bugs so far. I would strongly advise monitoring percent square retention. This practice is the most reliable indicator of potential plant bug feeding on squares at this time of year. Even with plant bugs easy to find in a cotton field, if 80 percent or more of the small terminal and lateral squares are being retained, plant bugs are not of economic concern (at that time). On the other hand, most of the plants bug that we see in cotton fields at this time of year are winged adults, which can invade cotton fields in a matter of one or two days. If low square retention counts call for plant sweeping, be sure to take eight to ten 25-sweep samples from representative areas of the field. An average of 8 or more plant bugs per 100 sweeps may indicate the need for a foliar insecticide treatment.
Although somewhat of a surprise after our very rainy spring, a couple reports of light spider mite damage in a few northeastern cotton fields were received this past week. Even following extended periods of rain, mites can still build up quickly after prolonged hot, dry weather. If these weather patterns persist, mites could well become a pest of concern. Let's hope not. Our generally late, poorly-rooted cotton crop cannot afford the kind of drought stress that is commonly associated with spider mite damage.
Although they will not begin to tip their hand until at least two weeks or so after blooming begins, stings bug levels appear to be on the high side this year.
Cotton scouting schools will be provided in Edgecombe, Sampson, Nash, Wilson, Halifax and Northampton counties, and possibly in the western Piedmont, in July. The dates, times, and locations should be posted in next week's issue of the North Carolina Pest News. A few other locations are also possible. Contact Dr. John Van Duyn (e-mail: john_vanduyn@ncsu.edu; telephone: 919-793-4428 ext. 133) for cotton scouting instruction offerings in the northeastern region of North Carolina.
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 June 30, 2003 by Stephen J. Toth, Jr.