Through cooperation of state agricultural research stations, U.S. Dept. of Agriculture-Cooperative States Research Service (USDA-CSRS) Interregional Project Four (IR-4), manufacturers and grower organizations, new herbicide labels for cabbage have been granted recently. Labels for the herbicides consist of national, regional, and state need and state emergency use labels. These herbicides provide adequate choices of labels for cabbage producers in the major commercial production areas. Starting with only three herbicides available in 1965 to a choice of 10 herbicides in 1994, growers can be more effective in control of weeds in cabbage.
Herbert J. Hopen
Travis W. Gannon, Matthew D. Jeffries, James T. Brosnan, Gregory K. Breeden, Kevin A. Tucker, and Gerald M. Henry
acceptable turf quality when mowing height was increased to 8.8 cm. Changes in common bermudagrass mowing height may affect the efficacy of PRE herbicides labeled for crabgrass control. However, minimal data have been published regarding integrated programs
Christopher A. Proctor and Zachary J. Reicher
are not currently labeled for use in turf, the objective of our study was to conduct herbicide screens to determine the efficacy of PRE or POST herbicides labeled for turfgrass to control purslane. Materials and Methods Preemergence and POST herbicide
Orville C. Baldos, Joseph DeFrank, and Glenn Sakamoto
)acetic acid + mecoprop + dicamba. Aminopyralid is a pyridine herbicide labeled for use in rice ( Oryza sativa ), wheat ( Triticum aestivum ), oil palm ( Elaeis guineensis ), and rubber ( Hevea brasiliensis ) plantations, rangelands, permanent grass pastures
Herbert J. Hopen
Based on recommendations for commercial cabbage producers fourteen herbicides were labeled over the thirty year period of 1965 to 1994. The number of herbicide choices ranged from two in 1965 and 1982 to ten in 1993 and 1994. The ten herbicides labeled for use in Wisconsin in 1994 are clomazone, DCPA, glyphosate, metolachlor, napropamide, sethoxydim, trifluralin, oxyfluorfen, paraquat and pyridate. Thirty two candidate herbicides were evaluated in thirteen of the thirty years but have not been approved for use in cabbage production. State “emergency” and state “third party” labels will be discussed as a means to provide herbicides for specific grower uses. The efficacy of each of the labeled herbicides will be discussed as supported by field, greenhouse and laboratory studies.
Emily E. Hoover, Frank Forcella, Neil Hansen, Steve Poppe, and Faye Propsom
Lack of effective weed control is the major limiting factor in strawberry production. With few herbicides labeled for use in this perennial crop, weeds are controlled using manual labor, cultivation, and one or two herbicide applications. However, these practices do not provide long-term, effective weed control, and weeds continue to be the number one reason why strawberry fields are removed from production due to a reduction in yield. The objective of this study was to evaluate weed control during strawberry plant establishment using woven woolen mats and spring-sown canola. The effects of these mulches on weed control and strawberry plant production were studied independently and in tandem. Weed and daughter plant counts were compared among treatments to test for differences. Wool mulch, both single- and two-ply, was an effective barrier to weeds within the strawberry rows. Planting canola between rows or broadcasting in combination with the wool mulch decreased the number of weeds when compared to other treatments. The four treatments that included wool had the highest number of rooted daughter plants when compared to all the other treatments except the weed-free plot. The canola treatments without wool mulch did not produce as many rooted daughter plants and were not statistically different from the weedy-check.
Richard L. Parish
Flame “cultivation” for weed control was developed about 50 years ago. The practice was very popular with Southern cotton farmers through the 1950s and 1960s, but lost favor when petroleum prices rose drastically in the 1970s. There is now a new interest in the practice of flame cultivation as a partial or total replacement for herbicides in vegetable crops. This interest is fueled by three factors: 1) an increasingly negative public perception of herbicides on vegetables, 2) a very limited selection of herbicides labeled for vegetables, and 3) limited efficacy of some of the herbicides that are registered. Flame cultivation, in combination with mechanical cultivation, can replace or supplement herbicides in some vegetable crops. The mode of action of flame cultivation is the bursting of cell walls in the weeds as the weeds are heated by a carefully directed LP gas flame. With most vegetable crops, the crop plants must be protected in some manner. This can be done with a water shield (flat fan water spray), height differential between weeds and crop, physical shield, etc. Much of the early work on flame cultivation of vegetables was done with sweet corn. Work is now underway on flame cultivation of lima beans and southernpeas, where multiple flame cultivations have proven effective at controlling weeds for which no herbicide is available.
Tyler J. Koschnick, William T. Haller, and Greg E. MacDonald
Restrictions on the endothall aquatic herbicide label include the use of endothall treated water for irrigating plants from 7 to 25 days after application. This interval was established to allow sufficient time for endothall to dissipate to levels that were considered safe for irrigation to prevent phytotoxicity to desirable plants. The affects of endothall on begonias (Begonia semperflorens `Vodka Cocktail'), pansies (Viola × wittrockiana `Atlas Purple'), petunias (Petunia hybrida), and impatiens (Impatiens wallerana `Lipstick') were determined by comparing aboveground dry weight to control plants after exposure to endothall in irrigation water. The objective was to determine if endothall concentrations used for aquatic weed control were phytotoxic to ornamental plants. Plants were irrigated every other day for 6 days in Expt. 1 with constant concentrations of endothall, and for 8 days in Expt. 2 with decreasing concentrations of endothall. Concentrations causing a 10% reduction in dry weight (effective concentration: EC10) compared to control plants showed there was a wide range of tolerance among plants exposed to endothall in irrigation water in the two experiments. Begonias, pansies, and impatiens had the lowest tolerance to two formulations of endothall in irrigation water with EC10 values ranging from 2 to 4 mg·L–1 (ppm) a.i. (a.i. based on acid equivalence) in both experiments. Petunias, which were more tolerant to endothall, had EC10 values of 15 and 34 mg·L–1 a.i. in Expt. 1 and 11 and 20 mg·L–1 a.i. in Expt. 2 for the amine and dipotassium formulations of endothall, respectively. Endothall did abscise flowers on impatiens after irrigation with endothall at concentrations of 10 mg·L–1 a.i. and higher. Effects of endothall on begonias at concentrations close to the EC10 values (2 to 3 mg·L–1 a.i.) were limited to growth inhibition with no apparent desiccation or necrosis of plant tissue.
E.T. Pippin, E.W. Bush, D.J. Lee, and R.E. Strahan
Weeping lovegrass (Eragrostis curvula) is commonly used in native areas bordering golf courses in the Southeastern United States. These areas do not receive significant levels of maintenance, thus weed encroachment is a problem that can negatively impact the functional and aesthetic values of the golf course. The objectives of this study is to determine which selective postemergent herbicides labeled for use on golf courses can remove weeds from Weeping Lovegrass and to determine the level of phytotoxicity. Herbicides included monosodium methane arsenate (MSMA 6.0) applied at 3.0 lb/acre a.i., sulfosulfuron (Certainty) at 0.047 lb/acre a.i., metribuzin (Sencor 75 DF) at 0.5 lb/acre a.i., and imazaquin (Image 70 DG) at a rate of 0.5 lb/acre a.i.. Treatments were applied on July 20, 2004 to 9.6 × 9.6 plots arranged in a randomized complete block design (RCBD) using Teejet 8005 nozzles at 40 psi calibrated to deliver 40 ga/acre. Plots were monitored daily and data was collected 0, 7, 14, 21, 28, 35, and 42 DAT. Sulfosulfuron and MSMA provided the highest level of weed control 35 DAT. Metribuzin and imazaquin provided limited weed suppression compared to the control. Initial phytotoxic damage to the Lovegrass was observed in all herbicide treatments. The highest level of phytotoxic damage was observed in the MSMA and Metribuzin treatments; however there was no apparent damage at 42 DAT. Herbicide applications of sulfosulfuron and MSMA are effective in reducing weed populations with acceptable levels of phytotoxicity to the Lovegrass.
Orville C. Baldos, Joseph DeFrank, and Glenn Sakamoto
effective pre- and postemergence herbicides labeled for roadside use need to be identified. The studies in this preliminary and regional report characterized the response of tropical fimbry to the preemergence herbicides, oryzalin and oxadiazon, and to the