I presented a paper similar to this one at last year's conference in which I discussed a number of different products which showed promise in helping reduce pesticide use on turf and outdoors around industrial facilities. This year I will briefly revisit developments with three of the products I discussed last year, since I believe these technologies continue to have great potential to reduce herbicide usage on military lands. These products are the Patchen WeedSeeker system, the Aqua Heat System, and corn gluten meal-based pre-emergent herbicides. In addition to these three products, I will also discuss varieties and usage of buffalograss, and new approaches to wood protection. This last area strays somewhat from a strictly grounds maintenance focus; however, next to herbicide usage, termiticides needed to protect buildings and other wooden structures on military installations probably account for more poundage of active ingredient applied within DoD than any other class of pesticide.

Keep in mind that the products, approaches, and equipment I am discussing are, for the most part, new and not totally proven. I am not advertising these materials, and anyone using them should maintain a "buyer beware" attitude.

Although I discussed this product last year, I think it is worth mentioning again because of its potential to significantly reduce the volume of herbicide used in controlling weeds in pavement cracks. To date, I am unaware of any DoD facility or agency that is evaluating the WeedSeeker although it is referenced in Air Force Model Pesticide Reduction Plan.

This product can best be described as a chlorophyll-identifying selective spray system. Each unit of the Weed Seeker contains an LED light source, an optical detector, spray nozzle valve cartridge, and electronics to interpret data and direct the operation of the unit. The LED light source emits a focused beam of light on the ground. Light reflected to the detector is processed by the electronics. If a weed is present, the valve cartridge is directed to spray a burst of herbicide. An extremely fast, highly reliable solenoid valve inside the valve cartridge controls spraying. The idea is to quickly hit vegetation with herbicide and not waste spray by hitting bare ground or pavement. Some current users of WeedSeeker Systems include CALTRANS (for roadside vegetation control), several California irrigation districts (for irrigation ditch vegetation control), and Asplundh Railroad Division (for railroad right of way weed control). Chemical savings of 40 to 50 percent are common, and payback on purchasing the equipment is within the first or second year of use.

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I also discussed Aqua Heat last year; however, unlike the WeedSeeker, there has been continuing interest in and testing of Aqua Heat within DoD.

The Aqua Heat System uses hot water (heated to 210^oF) to kill vegetation. The various types of Aqua Heat Systems all consist of a water tank, a patented diesel-fired heat exchanger, and a low pressure spray system with various types of nozzles or spray heads depending on the type of application. Mr. Don Teig at HQ ACC has been conducting some field evaluations with an Aqua Heat unit on Langley AFB in Virginia. Tests were conducted with the Aqua Heat Jr., which is a smaller version of units currently used in agriculture. Hot water is sprayed out of a boom system with 24 TeeJet nozzles and a swath width of about 4 feet. A piece of canvas is trailed behind the boom to maintain higher temperatures on the plants for a longer period of time. High temperatures must be maintained long enough to disrupt the waxy cuticle covering the leaves and stems of the weeds. The tests at Langley on areas with 12" grass as well as on weeds in cracks on the flight line showed complete control within 24 hours of treatment. During the growing season, treatments lasted about 3-4 weeks. No adjuvants have been evaluated at Langley. Aqua Heat, Inc. has been evaluating vegetable oil as an additive to increase the speed and effectiveness of treatments. They have also been evaluating the use of hot foam that may hold heat on the plants longer. Use of the soap or fatty acid-based herbicides to the water may also be a possible way to improve the efficiency of the hot water in breaking down plant cuticle.

An interesting non-herbicidal application of Aqua Heat Systems has been the use of hot water to control fire ants. In this application, a high temperature insulated hose is connected to the system, and hot water is applied inside a metal cone that is placed over the ant mound.

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Corn gluten meal (CGM) is 60 percent protein and approximately 10 percent nitrogen by weight. It s a byproduct of wet milling and is sold as feed for livestock and farm fish. CGM is a fine, yellow powder that can be pelletized and is insoluble in water. Several years ago, Dr. Nick Christians at Iowa State University found that CGM had pre-emergent herbicidal properties for both grasses and broadleaf weeds. Field tests have shown that CGM applied at 20 lb. per 1,000 square feet provides significant control of crabgrass; a number of other weedy grasses; and over 22 species of broadleaf weeds including clover, dandelions, and purslane.

Several formulations of CGM have been patented and are sold under the names Without Weeds and Dynaweed. Gardens Alive in Lawrenceburg, Indiana was the first to market a CGM product, and they continue to have exclusive rights to the home garden market under the Without Weeds label. However, commercial quantities of the material are available from Soil Technologies, Inc. under a licensing agreement with Gardens Alive. This product is called Dynaweed and is marketed primarily to private golf courses and professional sports facilities.

Again to my knowledge, this material has not been evaluated on DoD lands. It may present an opportunity to control grasses and weeds growing in pavement cracks as well as controlling weedy species invading improved turfgrass areas.

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The next product I would like to bring to your attention is a product as old as the hills or maybe older—buffalograss.

Buffalograss (Buchloe dactyloides) is a warm-season perennial grass native to the short grass prairies of the Great Plains. Native varieties of the grass can be found from Minnesota and Montana southward to Mexico. Buffalograss is cold, heat, and drought tolerant and has very few insect or disease pests. It requires little or no fertilization and can withstand submersion under floodwaters for up to 30 or 40 days. Turf areas with buffalograss can be established by seeding, plugging, or, most commonly, with sod.

The leading developer and distributor of buffalograss is the Creshaw-Doguet company. However, distributors are becoming more common even in the eastern part of the US.

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I would now like to move into a short discussion of termite baiting systems and borate wood protection systems. As I stated earlier, while these subjects may stretch the definition of "grounds maintenance," the area of wood structure protection has been and continues to be very important within DoD. The hazards associated with the use of inappropriate termiticiding techniques and materials on DoD installations can probably be recalled by those of you who may remember the environmental nightmares caused by the use of chlordane in military family housing units with subslab heating ducts.

In late 1994, Dow Elanco introduced the first commercial termite baiting system—Sentricon. Several new players have entered the market more recently with somewhat similar systems.

The use of bait systems is a totally different concept than traditional termite control that relies on a barrier of insecticide. With a barrier, a soil-persistent pesticide is applied to new structures prior to pouring of a slab, or in the case of existing structures, the pesticide is applied completely around the foundation and, if necessary, beneath the foundation and footers by drilling holes in walls/floors and injecting the pesticide. Pesticides used in barrier treatments are acutely toxic to termites (kills them almost immediately on contact), and, in some cases, are repellent to termite workers (helpful when you might have some breaks in the barrier). In contrast, bait systems do not form barriers, but depend upon foraging termite workers to locate their "tasty" cellulose baits and to continue living just long enough to pass slow-acting poisons around the termite colony.

The Sentricon system consists of plastic tube bait stations with slits in the sides. An untreated wood material is placed in each bait station that is then inserted into the ground around a structure at 10-20 ft intervals and about 12-18 inches from the foundation. Wood in the bait stations is inspected monthly or bimonthly, and if a "hit" is found, the untreated wood in the bait station is replaced with paper toweling treated with 0.5 percent hexaflumuron. (Hexaflumuron is a chitinase inhibitor that prevents molting in the termites that feed on it. Unable to molt, the termites die.) After further monthly monitoring (and given the slow-acting hexaflumuron this is typically 3-4 months) shows cessation of termite activity, untreated wood is again added to the bait station and maintenance level monitoring is resumed.

Two additional companies have recently entered the termite bait system market. FMC is marketing FirstLine that, unlike Sentricon, is an aboveground system. With FirstLine, a termite surface tube is broken, and the bait station is inserted between the open ends of the tube. Termite workers repair the tube break and start feeding on the bait. In this case the bait is laced with sulfluramid, a slow-acting stomach poison.

American Cyanamid has developed the Subterfuge System that employs Cyanamid's premier slow-acting insecticide—hydrmethylon, also used in Maxforce cockroach and ant baits. Like the Sentricon System, Subterfuge is a below-ground bait. Unlike Sentricon, there is always treated bait in the bait tubes, and Cyanamid claims that they have a gourmet mixture in their baits which is more palatable to termite workers than the pine wood in Sentricon.

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The use of borates is another area of wood protection that has recently been expanding in response to the environmental hazards of traditional wood preservatives such as creosote, pentachlorophenol, and zinc, tin, and copper salts. Unlike termite baits, borate wood treatments have been around (especially in Australia and New Zealand) for a considerable time, and they have a proven track record of protection. Borates also protect against an entire spectrum of wood problems—termites, beetles, carpenter ants, rot fungi, and so on. With wood-destroying insects, the borate mode of action seems to be to kill the gut fauna making it impossible for the insect to digest cellulose, thereby starving to death.

The first borate marketed in the US was BoraCare introduced in 1989 for the protection of log homes. BoraCare contains disodium octaborate tetrahydrate (DOT) dissolved in ethylene glycol. A major competitor of BoraCare is Timbor introduced in 1991 by US Borax. Timbor is a water-soluble DOT formulation labeled for remedial wood treatment applications. Subsequently, NISUS, the manufacturer of BoraCare has introduced other formulations of BoraCare—Jecta (a dense borate fluid that is injected into drilled holes in posts, landscape timbers, and other ground-contacting wood); and Impel Rods (concentrated sodium borate rods which slowly dissolve and diffuse through wet wood after the rods are inserted into drilled holes).

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This has been only a very brief review of just a few of the emerging technologies and materials that have the potential over time to reduce synthetic and/or higher toxicity pesticide use. There are many more areas in which opportunities exist to reduce reliance on pesticides generally by working with nature rather than against nature. If you would like more information on any of the items mentioned in this talk, please don’t hesitate to contact me. Thank you for your attention.