The Environmental Protection Agency has granted federal labels for Steward and Tracer insecticides to be used on peanuts in 2003.
Below is some pertinent information on these products and some suggestions on how they might be best used on peanuts:
Steward (Indoxacarb) is sold by DuPont and was labeled in July of 2002. It has a unique chemistry and does not fit in any common class of insecticides. The label has “Caution” as a signal word indicating a relatively low mammalian toxicity.
Applicators should wear long-sleeved shirts, long pants, shoes, socks and chemical-resistant gloves. There is a re-entry interval of 12 hours.
The pre-harvest interval on peanuts is 14 days.
Steward is toxic to mammals, birds, fish and aquatic invertebrates. Do not apply directly to water or allow runoff to contaminate water. This product is highly toxic to bees. There are no known compatibility problems with other commonly used peanut pesticides.
Steward is a suspension concentrate containing 1.25 pounds of active ingredient per gallon. The use rate on peanuts is 9.2-11.3 fluid ounces of product per acre. One gallon of Steward will treat 14-11.5 acres depending on the rate.
The minimum interval between treatments is five days. Do not apply more than 45 fluid ounces (0.44 pound active ingredient) per acre per crop.
On peanuts, Steward is labeled for control of corn earworm (CEW), beet armyworm (BAW), fall armyworm (FAW) and granulate cutworm (GCW).
Steward will fit best in peanuts, says University of Georgia Extension Entomologist Steve L. Brown, as a BAW product. It performed very well in sporadic (but severe) outbreaks in 2002. It also did a good job on GCW which has become more difficult to kill in recent years. Less expensive options are available when CEW and FAW are the dominant species.
Steward is weak on velvetbean caterpillar (VBC). Although VBC can be controlled easily with other products, growers should be aware that when spraying mixed populations, VBCs will probably survive, and their numbers can increase rapidly.
Steward is reported to be very safe on some insect parasitoids. However, in limited experience with the product, it can be very damaging to populations of predaceous beetles commonly found in peanuts.
Ground beetles, especially the large Calosoma ground beetle, are very sensitive to Steward.
Tracer (spinosad) is sold by Dow AgroSciences and was labeled late in the fall of 2002. Tracer also has a unique chemistry and does not fit into any of the major classes of insecticides. Tracer carries the signal word “Caution” indicating a low level of mammalian toxicity.
Applicators and other handlers should wear long-sleeved shirts, long pants, shoes, socks and waterproof gloves. The re-entry interval is four hours.
Tracer is highly toxic to bees and aquatic invertebrates. Do not apply directly to water or to allow runoff to contaminate water. There are no known compatibility problems with other commonly used peanut pesticides.
Tracer contains 4 pounds of active ingredient per gallon. Rates are 1.5-3 fluid ounces of product per acre for all targeted pests except the armyworms which require a rate of 2-3 fluid ounces of product per acre.
Do not apply more than 9 fluid ounces (0.282 pound active ingredient) per acre per crop, or make more than three applications per calendar year. Do not make applications less than seven days apart. Do not harvest or graze crop residue for 14 days after last application.
On peanuts, Tracer is labeled for control of CEW, red-necked peanut worm (RNPW), soybean looper (SBL), VBC, BAW, FAW, yellow-striped armyworm (YAW) and several other incidental pests. Because of its broad spectrum of activity on lepidopterous pests, Tracer may be a good option in cases of mixed populations, especially when fall armyworm and beet armyworms are present.
There have been a few indications of pyrethroid-resistant tobacco budworms being found in peanuts. Although there is currently no indication of a widespread problem, Tracer could be a good substitute for Asana and Karate if necessary.
On some species, Tracer efficacy will decline as larvae increase in size.
For example, activity on large FAW and BAW may be disappointing. Because of its short pre-harvest interval (three days of nut harvest) Tracer gives us an option for late-season insect control. All other peanut insecticides have at least 14 day pre-harvest intervals, and foliage feeders (especially VBC) often cause damage just prior to harvest.
Also, Tracer is the only registered insecticide that allows feeding of peanut hay, although feeding often is restricted by use of fungicides.