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Title:	Evaluation of plant growth regulators for use in grounds maintenance at military installations
Authors:	Nelson, Linda S. Getsinger, Kurt D. Luu, Kien T.
Keywords:	Turf management Plant growth inhibiting substances Grounds maintenance Plant regulators
Publisher:	Environmental Laboratory (U.S.) U.S. Army Engineer Waterways Experiment Station.
Series/Report no.:	Technical Report;EL-92-24
Abstract:	A 3-year study to evaluate the use of plant growth regulators (PGRs) for reducing grounds maintenance costs was conducted at four military installations. Test plots were treated once a year, in the spring, for 3 consecutive years at the following installations: Red River Army Depot, Texas; Fort Leonard Wood, Missouri; Charleston Naval Weapons Station, South Carolina; and Willow Grove Naval Air Station, Pennsylvania. The objectives of this study were to: (a) evaluate the effectiveness of PGR treatments on the dominant turf species at each location; (b) determine the cost-effectiveness of PGR use versus conventional mowing practices; and, (c) provide guidance for incorporating PGRs into installation grounds maintenance programs. Roundup + Oust and Oust + Escort were the most successful treatments evaluated over the 3-year period at the Red River Army Depot. Both treatments provided control of problem broadleaf and grass weed species without adversely affecting the desirable bermudagrass. The average duration of vegetation suppression was 10.7 weeks for Roundup+ Oust and 8.7 weeks for Oust+ Escort and was sufficient to reduce mowing to mowing alone. Cost savings ranged from 5 to 55 percent that of mowing, with Roundup + Oust being the most economical product evaluated. Results of tests at Fort Leonard Wood showed that Embark + Escort and Embark + Telar were the most effective treatments evaluated. Both treatments provided acceptable weed control and the longest period of vegetative and seedhead suppression (9.3 weeks) of the two target grass species, Kentucky 31 tall fescue and Kentucky bluegrass. Other treatments that performed well but for shorter time periods included Event, Royal Slo-Gro + 2,4-D, and Manage + Telar. Several treatments caused temporary turf discoloration, however effects were considered tolerable for low- to medium-quality turf areas. On semi-improved grounds at Fort Leonard Wood, six treatments were cost-effective when compared to mowing alone. These treatments and respective estimates of dollars saved included: Event and Royal Slo-Gro + 2,4-D, 34 percent; Embark, Embark + Telar, and Manage + Telar, 32 percent; and Embark + Escort, 29 percent. Oust was the most effective growth regulator tested on bahiagrass turf at the Charleston Naval Weapons Station, providing an average 10 weeks of vegetative and seedhead control throughout the study. Application of Oust caused temporary phytotoxic effects on bahiagrass; however, at no time were the discoloration effects considered objectionable. Other treatments that performed well included Event and Royal Slo-Gro. Telar and Embark + Fusilade were least effective. Estimates of cost savings were greatest with the use of Oust, which averaged a 57 percent lower per acre cost than that of mowing. Based on data collected at the Willow Grove Naval Air Station, the most successful PGR treatments evaluated included: Embark + Escort, Telar + Manage, Royal Slo-Gro + 2,4-D, MON4625 + Banvel + 2,4-D, Escort + Manage, and Event + 2,4-D, in order of decreasing effectiveness. Embark + Escort was the most consistent treatment, providing adequate broadleaf weed control, seedhead inhibition, and 10.6 weeks of acceptable vegetation suppression. Embark + Escort and Telar + Manage were the most cost-effective treatments compared to current mowing practices. Differences in cost per acre compared to mowing were 52 and 29 percent, respectively. Escort + Manage, Royal Slo-Gro + 2,4-D, and Event+ 2,4-D averaged 10 percent lower costs per acre than mowing. General and specific recommendations for PGR use at all test sites are provided.
URI:	http://hdl.handle.net/11681/26027
Appears in Collections:	Technical Report