Towers, 2004 ). Limited options exist for selective khakiweed control in managed turfgrass. Trifloxysulfuron is the only herbicide labeled for the postemergence control of khakiweed in turf ( Anonymous, 2009 ). However, turfgrass managers also use
, and trifloxysulfuron—are not currently registered for aquatic use. However, the efficacy, selectivity, and potential use rates of these herbicides are being evaluated under experimental use permits (EUPs) to determine whether they may be useful in
including s -metolachlor + pendimethalin (grower standard) and experimental treatments of dimethenamid-p, flumioxazin, flumetsulam, isoxaflutole, mesotrione, sulfentrazone, and trifloxysulfuron. In 2004, a second trial evaluated PRE-applied s -metolachlor
rates that provide limited herbicidal activity on Solanaceous weeds, such as black nightshade ( Solanum nigrum ), which is closely related to pepper ( Stall 1999 ; Vencill 2002 ). Herbicide treatments included trifloxysulfuron (Envoke®; Syngenta Crop
., 2003 ; Umeda and Towers, 2006 ). However, its use is restricted only to row middles, and herbicide contact with plastic should be avoided ( Gowan Co., 2007 ). Trifloxysulfuron, another sulfonylurea herbicide, provides effective control of many weed
the only source of water at both locations. Herbicide treatments included a nontreated check, MSMA (MSMA 6.6 L; Drexel Chemical Co., Memphis, TN) at 2500 g⋅ha −1 a.i., trifloxysulfuron (Monument; Syngenta Crop Protection, LLC, Greensboro, NC) at 28
encouraging result from these studies was that 10 of the herbicide treatments (rimsulfuron, trifloxysulfuron, flazasulfuron, glufosinate + clethodim, glufosinate, pronamide, foramsulfuron, glufosinate + glyphosate, glyphosate + diquat, and glyphosate
Transition of perennial ryegrass from bermudagrass athletic fields in the spring delays the establishment of bermudagrass when the establishment period is limited. The objective of this field study was to determine the effects of transition herbicides on the establishment of seeded bermudagrass. Treatments consisted of an untreated control, foramsulfuron, rimsulfuron, trifloxysulfuron sodium, metsulfuron methyl methyl, isoxaban, and oxadiazon at low- and high-labeled rates for transitioning perennial ryegrass. `Riviera' bermudagrass [Cynodon dactylon (L.) Pers.] seed was seeded immediately after treatment and 2 weeks after treatment. Turfgrass coverage was evaluated visually and by digital analysis. Although differences between methods of turfgrass coverage evaluation varied, the differences between treat-ments were similar. There was no significant differences in turfgrass establishment between foramsulfuron, rimsulfuron, trifloxysulfuron sodium, metsulfuron methyl methyl, and the control for either seeding date or rate. Turfgrass coverage was significantly less for isoxaban and no turfgrass was established in the oxadiazon treatments. Initial results of this research indicate that bermudagrass seed can be seeded immediately following the application of foramsulfuron, rimsulfuron, trifloxysulfuron sodium, and metsulfuron methyl methyl.
With the potential introduction of glyphosate-resistant kentucky bluegrass (GRKB) (Poa pratensis L.), postemergence herbicides must be identified for renovation from glyphosate-resistant stands or control escaped GRKB. Field experiments were conducted in Indiana, Maryland, New Jersey, and Virginia from July to September 2004 to investigate efficacy of postemergence herbicides for kentucky bluegrass control. Herbicides tested included clethodim at 0.28 kg·ha–1 (a.i.), fluazifop-p at 0.43 kg·ha–1 (a.i.), formasulfuron at 0.03 kg·ha–1 (a.i.), glufosinate at 1.12 kg·ha–1 (a.i.), glyphosate at 1.68 kg·ha–1 (a.i.), rimsulfuron at 0.03 kg·ha–1 (a.i.), sethoxydim at 0.53 kg·ha–1 (a.i.), and trifloxysulfuron at 0.03 kg·ha–1 (a.i.). One and two applications of each herbicide were applied to separate plots with the sequential applied 4 weeks after initial treatments (WAIT). Single applications of glyphosate completely controlled kentucky bluegrass 4 WAIT in Maryland, New Jersey, and Virginia. Glufosinate completely controlled kentucky bluegrass with one application in Maryland and New Jersey but single and sequential applications provided only 80% to 88% control in Indiana and Virginia. Foramsulfuron and rimsulfuron required sequential applications for complete kentucky bluegrass control 8 WAIT in New Jersey and Maryland but <82% control was obtained in Indiana and Virginia. Trifloxysulfuron controlled kentucky bluegrass 95% to 100% with single applications in Maryland, New Jersey, and Virginia. Single applications of clethodim, fluazifop, and sethoxydim provided minimal stand reductions but sequential applications controlled kentucky bluegrass 65% to 100%. Results suggest glufosinate and trifloxysulfuron have the greatest potential for controlling GRKB while other herbicides provided erratic control and require sequential applications.
Selective broadleaf weed control is a major economic issue facing commercial landscapers and homeowners alike. Minimal selective post-emergent weed research has been successful in controlling landscape weeds. The objectives of this experiment were to determine the efficacy of seven selective broadleaf herbicides [nicosulfuron (0.66 oz/acre), flumioxazin (8 oz/acre), penoxsulam (2.3 fl oz/acre), bensulfuron (1.66 oz/acre), glyphosate (1% by volume), sulfentrazone (8 fl oz/acre), trifloxysulfuron (0.56 oz/acre) and the control] and to determine the ornamental phytotoxicity on three groundcover species (Liriope muscari, Ophiopogon japonicus, and Trachelospermum asiaticum). A RCBD design was used with five blocks. Each block was split establishing either mulched or bare soil plots (nonmulched). The ground-covers were established three months before herbicide application. On 29 June 2005, four weed species were evenly seeded into the blocks with one hundred seeds each of Sesbania exaltata, Ipomea hederacea, Amaranthus retroflexus, and Euphorbia maculata. Herbicides were applied using a CO2 backpack type sprayer on 6 Sept. 2005. Plant and weed control data were taken to evaluate phytotoxicity and efficacy at 0, 1, 7, 14, and 28 DAT. On 27 Oct. 2005, weeds were harvested from each plot and dried for a minimum of 48 h and weighed. No significant differences in phytotoxicity were observed on either Liriope muscari or Trachelospermum asiaticum. However, there was a significant increase in phytotoxicity exhibited by the Ophiopogon japonicus treated with sulfentrazone compared to all of the other herbicides. Glyphosate demonstrated the best overall control of all broadleaf weeds except Sesbania, while trifloxysulfuron showed the best control of Sesbania. There were no significant differences in herbicide efficacy between the mulched and nonmulched plots. Further research is being done to measure the effects of herbicide efficacy and phytotoxicity in 2006.