• Spring Transition of Tifway (419) Bermudagrass as Influenced by Herbicide Treatments

      Kopec, David M.; Gilbert, Jeff J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      The transition from perennial ryegrass back to bermudagrass is often problematic. Prolonged periods of ryegrass persistence and/or loss of complete turf is troublesome and not favorable to the re-establishment of the bermudagrass base. A group of select herbicides were applied in May 2000, to assess their response to enhance the removal of perennial ryegrass, and to enhance recovery of the bermudagrass. CORSAIR (Chlorosufuron) applied at 1.0 ounce/product/acre resulted in reduced turfgrass quality from three to six weeks after treatment, with a decrease in color at three weeks. This treatment caused moderate suppression of the turf and an enhanced transition from perennial ryegrass to Tifway (419). MANOR (Metsulfuron) applied at 0.4 ounce/product/acre caused a slight growth suppression, acceptable turfgrass color, but a noticeable decrease in turfgrass quality up to six weeks after application. MANOR increased turf density and minimized scalping by seven weeks after treatment (July 24, 2000) SURFLAN when applied at 1.5 lb AI/A, produced acceptable quality turf, no visible growth suppression, acceptable overseed turf quality and color. SURFLAN did not provide any affect as a transition agent in this test. KERB did not greatly enhance transition, and was slightly more effective at 0.5 lb AI/A, than at the 1.0 lb AI/A rate. Both rates of KERB produced acceptable turfgrass color throughout the test. Turfgrass quality diminished to low levels from July 18 to July 24, ranking lowest in quality. KERB treated turf tended to "scalp" more than other treated turfs and thinned the grass at the high rate of 0.50 lb AI/A. FIRST RATE applied at 75 grams AI/hectare caused slight visible suppression for two weeks after treatment, an acceptable quality turf (on six of seven evaluation dates), acceptable turfgrass color and turf density. FIRST RATE did enhance transition, but less so than CORSAIR, possibly less than MANOR, and certainly less than AEF 130630. PROXY was applied on four dates (four, three, two, and zero weeks prior to June 3), selected as a "calendar target" dates observe transition. PROXY when applied on May 13, provided a short transition effect, for a period of about two weeks. Applications made later had little effect whatsoever, on Spring transition back to bermudagrass. From May 19 to June 5, the two "early" applications of PROXY, generally increased turfgrass color and quality scores, most likely by having a PGR response on perennial ryegrass. AEF 130630 readily enhanced Spring transition from perennial ryegrass to Tifway (419) bermudagrass, especially in May and June. All three application rates caused visual suppression of the turf from May 19 until June 5 . Turfgrass color and quality were affected by AEF 130630. The maximum expression occurred for the 0.42 ounce/product/M rate by May 25 (which remained until at least June 5). Mean color scores here were 5.3, on both dates. The high rate 0.64 ounce/product/M actually caused less color reductions in the turf (perhaps as a function of the quicker removal of ryegrass). Reduced turf quality resulted three weeks after treatment for both the low and high rates (means = 5.0). The turf was similar to that of the control plots, afterwards, and superior by both middle and late July time periods.
    • Rove Beetle Control Using Selected Insecticide Agents on Bentgrass Greens Turf

      Kopec, David M.; Gilbert, Jeff J.; Gauge, Dawn; Smith, Kirk A.; Pessarakli, Mohammed; Piscopo, Dallas; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Rove beetles (Osorius planifrons) can and often do cause extensive surface disruption on turf mowed at greens height. Two rates (1x and 2x of product label rate) of Crusade (fonophos), Sevin (carbaryl), DeltaGard (deltamethrin), and Chipco Choice (fipronil), were applied on September 28, 2001 on an SR1020 creeping bentgrass green. Percent rove beetle control was nearly 100% for DeltaGard at 9, 15 and 32 days after treatment, regardless of rate. Crusade had nearly 100% control at either rate at 9 days after treatment, which decreased slightly to 90-93% control by 15 days after treatment. Deltamethrin maintained 95% and 98% control at the 1x and 2x rates respectively, at the close of the test (32 DAT). Crusade maintained 93% and 98% control at the 1x and 2x rates at 32 DAT. Chipco Choice had a maximum control of 24% at 7 DAT when applied at the 1x rate, and a maximum control of 57% at 32 DAT when applied at the 2x rate. Sevin provided low levels of control which peaked at 53% at the 1x rate at 9 DAT, which decreased immediately afterwards. Delta-Gard and Crusade provided excellent control levels of rove beetles on SR1020 bentgrass greens.
    • 2002-2003 Overseeding Turf Trials

      Kopec, David M.; Gilbert, Jeff J.; Pessarakli, Mohammed; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Sixty-four overseed turf entries were evaluated from October 2002, to June 2003 for turf when overseeded on Tifway bermudagrass fairway turf. Overseed entries included 43 single variety (or experimental synthetics) of perennial ryegrass, 2 annual ryegrasses, 6 entries of intermediate or 'hybrid' ryegrass, 5 entries of Poa trivialis (PT), one blend of perennial ryegrass, 4 mixtures (two or more species together) and 3 fescues. The main effect of "overseed grass entry" was highly significant on all dates for all visual turf responses, which included establishment, color quality, density, texture, and spring transition. The greatest amount of variation occurred within the perennial ryegrass group as a whole, showing the diversity within this species for overseeding performance. Annual ryegrass provided quick germination and ground coverage in the fall and a quick spring transition, but was of poor turf quality. Intermediate ryegrasses had performance values between that of perennial and annual ryegrass, some of which provided moderately good turf performance and good transition. Poa trivialis was slow to establish, but provided good quality and excellent plot texture, however they had poor transitional qualities. Final quality mean scores ranged from 3.0 (P-02-0047 PT) to 7.7. There were three entries, which averaged 7.7 at the close of the test, which included Mach 1 PR, SR 4500 PR, and Pace PR. The entries IG-2, Greenville PR, Express PR, Bar LO 2001, Hawkeye, Partee finished at 7.3 for quality. Among the intermediate ryegrass entries, Froghair finished with a mean quality score of 7.0, followed by Pick 00- A-LH (5.3). All three fescues produced mean quality scores of 6.0 or better on 8 June (Hardtop fescue leading at 6.7 for quality). The Labarinth tall fescue did have 62% Bermuda at the end of the test, compared to 65% for all entries at that time. Entries which had a mean quality score of 7.0 or more in June, along with a bermuda transition of close to 75% or more at the termination of the test included the following entries; Citation Fore, Mach 1, BarGold, Bar LP 2001, Pace, Greenville OSP, and Express.
    • Spring Greenup of Dormant Non-Overseeded Bermudagrass

      Gilbert, Jeff J.; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Spring Greenup of dormant bermudagrass would be desirable from a use and/or aesthetic standpoint if low cost amendments could be incorporated into early season management. Four fertilizers, activated charcoal and lawn paint were applied 1 March, 2001 to a fully dormant Tifway (419) bermudagrass turf. Activated charcoal and lawn paint treatments increased turf growth, visual quality and early season turf color compared to fertilizer treatments. All fertilizer treatments generally produced greater growth than the non-treated control, while Dune liquid fertilizer produced significantly greater clippings than the other fertilizer sources tested. Visual quality was enhanced 27 days after treatment by charcoal and paint treatments. Increased canopy and soil temperatures realized from the physical amendments (charcoal or paint) were enough to induce enhanced growth, turf quality and color over chemical (fertilizer) applications.
    • Response of Common Bermudagrass Sports Turf to Select Herbicides Used for Spring Transition Enhancement

      Kopec, David M.; Gilbert, Jeff J.; Pessarakli, Mohammed; Evans, Phillip; Ventura, Bo; Umeda, Kai; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Common bermudagrass often struggles with spring transition, when overseeded the previous fall with turf-type perennial ryegrass. Select herbicides were applied once on an overseeded common bermudagrass baseball field, on either an early May, or late May application in both 2003 and 2004 summer in order to evaluate their performance as an aid in spring transition. The same treatments were applied to the same plots in the two year study. The sulfonyl urea products of Tads or foramsulfuron 'Revolver', rimsulfuron 'Tranxit', trifloxysulfuron 'Monument', caused noticeable necrosis to the perennial ryegrass, which lasted up to 30 days after application, as the common bermudagrass became re-established. The other s.u. product of chlorsulfuron 'Manor', was similar to pronamid 'Kerb', which did not cause as much necrosis as the other products. However, both 'Manor' and 'Kerb' had lesser effects on transition as did the other products. This was generally true in both years. The greatest amounts of necrotic turf (percent plot straw values) occurred 30 days after application, regardless if products were applied the first week in May ('early'), or when applied the last few days of May ('late'). The e herbicide treatment main affect was significant for most turfgrass responses when herbicides were applied 'early'. This was true in both years of the study. In year 1 (2003), the 'late' application of herbicides were less effective in enhancing transition, but in year 2 (2004) the treatment affect was significant for enhancing the removal of ryegrass and enhancing the re-introduction of the underlying bermudagrass. The 'early' application program did allow for a longer bermudagrass summer season, (before the next fall overseeding) , which is deemed helpful in promoting good bermudagrass turf growth before the next overseed season Perennial ryegrass will last long into midsummer, when left untreated.
    • Evaluation of Timing Applications of Ethephon and Trinexepac-Ethyl for Seed Head Suppression of Poa annua

      Kopec, David M.; Gilbert, Jeff J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Seed head production from Poa annua is problematic on winter turfs, whether they are overseeded or not. Flowering culms are unsightly, prevent a uniform surface, and insure a continuous crop of seeds for the future. A field test was conducted to evaluate the effects of PROXY and a PROXY/PRIMO PGR tank mix for seed head control. Treatments were applied on three different dates in order to evaluate the degree of response of treatments and help define treatment window applications for future programs. PROXY when applied alone at 5 ounces/product/M produced a maximum of 60% seed head control at 26 days after a single application on February 15, and 83% seed head control at 27 days after a single application on March 1. A tank mix of PROXY/PRIMO (5.0/0.25 ounces/product/M) generally produced greater seed head control than PROXY alone. The tank mix produced seed head control effects quicker, greater, and longer than PROXY alone. Seed head suppression and percent seed head control was greatest when products were applied initially on either February 15 or March 1, 2001. PROXY/PRIMO produced the darkest color turf when applied on either February 15 or March 1. At least three tank mixes seem to be needed, applied monthly to suppress/control seed heads throughout the winter/spring season.
    • Evaluation of Fungicides for Control of Rapid Blight of Poa trivialis (2002)

      Olsen, Mary W.; Bigelow, Donna M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Rapid blight is a new disease of cool season turf grasses that has occurred on several golf courses in Arizona over the past five years. It is now known to be caused by a Labyrinthula sp., an organism in a group referred to as the marine slime molds. A trial was conducted in fall 2002 to evaluate efficacy of selected fungicides for control of rapid blight at a golf course in central Arizona with a previous history of disease. Plots were established in October 2002 on a practice green on which Bermuda was overseeded with Poa trivialis. Treatments included Compass, Insignia, Fore, Eagle and Aqueduct in various combinations and application dates. Disease symptoms appeared several days after the first mowing and continued for over three months. Results indicate that both pre- and post-plant applications of Fore and post-plant applications of Insignia and Compass gave good control. The best results were obtained with the treatment of Fore combined with Compass that included a pre-plant application of Fore, or with post-plant application of Insignia.
    • Interactive Effects of Salinity and Primo on the Growth of Kentucky Bluegrass

      Pessarakli, Mohammed; Marcum, K. B.; Kopec, David M.; Qian, Y. L.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Kentucky bluegrass (Poa pratensis L.), cv. Nu Star was studied in a greenhouse to evaluate its growth responses in terms of shoot length and dry weight under NaCl (sodium chloride) salinity and different levels of Trinexapac-ethyl( primo Max). Plants were grown hydroponically under control and one level of salinity [EC (electrical conductivity) of 5 dS/m] and three levels of primo Max (0.3, 0.6, and 0.9 oz/1000 ft²), using Hoagland solution No. 1. Plant shoots (clippings) were harvested weekly, oven dried at 60 oC, and dry weights recorded. At each harvest, shoot length was measured and recorded, percent visual canopy green cover was also estimated. The results show that shoot length and shoot dry weight (DW) of Kentucky bluegrass significantly decreased with both salinity and primo treatments, although the differences in shoot length and shoot DW were not significant between primo treatments at 0.6 and 0.9 oz/1000 ft² application rates. The green coverage of the turf canopy decreased under salinity stress, and the reduction of green canopy coverage by salinity was more pronounced when turf was treated by primo, suggesting that primo significantly reduced the salt tolerance of Kentucky bluegrass. The above results were observed for both cumulative as well as the weekly growth responses.
    • Penoxsulam as a Potential Post-Emergence for Khakiweed (Alternanthera pungens)

      Kopec, David M.; Gilbert, Jeff; Pessarakli, Mohammed; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Post emergence applications of penoxsulam herbicide were generally ineffective in weed control of Khakiweed, (Alternanthera pungens). Moderate control was achieved by the high rate of granular Penoxsulam (0.052 G, 180-lbs. acre). This treatment had 28%, 34%, and 32% Khakiweed control on September 20, September 23 and September 29, respectively. Other rates resulted in minimal or negative control. The liquid SC formulation provided minimal control, at rates tested. Penoxsulam did discolor khakiweed, but did not cause enough injury to result in stand reduction. Further aspects for investigating Penoxsulam for control of this weed is presented.
    • Use of Foramsulfuron (TADS) as a Transition Agent for Removing Perennial Ryegrass Overseed from Tifway 419 Bermudagrass

      Kopec, David M.; Gilbert, Jeff J.; Pessarakli, Mohammed; Umeda, Kai; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Two rates of Foramsulfuron (TADS) were applied at both low (0.50 lbs/M) and high (1.0 lbs/M) rates of water soluble nitrogen in May 2003 to enhance the transition from ryegrass to bermudagrass. Overall, the 0.2-ounce product/M rate of TADS herbicide, regardless of applied -N- rate produced excellent turfgrass color, density and overall turf quality. The same 0.2-ounce rate produced a good spring transition. Overall, the 0.4-ounce rate of TADS produced slightly more bermuda than the 0.2-ounce rate at the "end" of the transition (June 6). The higher fertility rates yielded better quality, color and turf density during transition then the low -N- rate when TADS was applied at the 0.4-ounce/product/M rate. Note that Tifway bermudagrass has in general, a more decumbent growing bermuda than common bermudagrass, which is less competitive during spring transition than Tifway 419. In summary, all rates of TADS enhanced spring transition. When the high rate of TADS is used on Tifway 419 (0.4 ounce/product/M), then better turf performance was achieved with the higher -N- rate applied in early May.
    • School IPM

      Gouge, Dawn H.; Smith, Kirk A.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
    • Subterranean Termite (Isoptera: Rhinotermitidae) Mortality Due to Entomopathogenic Nematodes (Nematoda:Steinernematidae, Heterorhabditidae)

      Weeks, Brian; Baker, Paul; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Two species of entomopathogenic nematode were studied in terms of their survivability, detectability by the subterranean termite Heterotermes aureus, and their ability to induce mortality in H. aureus. Heterorhabdidtis bacteriophora (Poinar) and Steinernema carpocapsae (Weiser) are nematodes sold commercially as a means of biological control for termites. We used a laboratory method to determine how effective these nematode species might be under field conditions. Tests showed a difference in the survivability between nematode species and also ability to kill termites. It was also shown that H. aureus had no ability to detect either nematode species when given a choice between arenas infested with nematodes and not. Though nematodes might have some limited capacity for termite control, those considering using nematodes to control Heterotermes aureus may want to consider the species of nematode before making a purchase.
    • Velocity Herbicide for Poa Control in Overseeded Turf

      Kopec, David M.; Gilbert, Jeff; Pessarakli, Mohammed; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Velocity, (bis pyrobac-sodium) was applied at different ai/a rates in multiple application series to evaluate treatments for post emergence seed head and vegetative control of Poa annua var. annua. Velocity herbicide, when applied to perennial ryegrass overseed turf with heavy PA infestations, caused periodic discoloration of the ryegrass and yellowing/bronzing of the PA. The leaf yellowing of PA caused by Velocity is in contrast to color enhancement of PA from Proxy/Primo tank mixes. Seed head suppression of PA from Velocity was slightly greater in early April, than in early March. As cumulative treatment amounts of active ingredient of Velocity increased, the seed head suppression increased for treatments beyond the 30 + 30 gm ai/a rate. Above this rate, seed head suppression was increased, but not consistently with the applied active ingredient rate. Seed head suppression of PA on March 5 from Velocity ranged from 35% to 75% among Velocity treatments applied at 30, 45 and 60 grams ai/a. Embark alone had fair seed head suppression from early to mid-March, but decreased dramatically afterwards. There was no benefit of the 30 + 60 gm ai/a treatment, over the 60 + 60 gm ai/a treatment for seed head suppression of PA. Biological response in terms of absolute rate of ai/a applied and response to cumulative amounts of total Velocity were not consistent for PA seed head suppression or vegetative control. No product affectively reduced vegetative control of PA in a highly infested stand of PA which was 40-50% PA. If Velocity is to be competitive against other PA seed head reducing products, rate structures and timings may have to be amended for more multiple applications.
    • Investigations of the Host Range of Labyrinthula terrestris, a New Turfgrass Pathogen

      Bigelow, Donna M.; Olsen, Mary W.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Non-salt tolerant cultivars of rice, lettuce and radish as well as salt tolerant varieties of alfalfa, barley, and wheat were screened in the greenhouse and laboratory to determine if Labyrinthula terrestris, a new turfgrass pathogen, could infect plants other than turfgrasses. Wheat, barley and rice plants were infected, symptomatic and died. Radish and lettuce were infected but nonsymptomatic. Alfalfa was not infected and exhibited no symptoms. Results indicate that L. terrestris is capable of infecting and causing symptoms in plants other than cool season turfgrasses.
    • Observations of TADS Foramsulfuron Formulations on Sea Isle I Paspalum as Affected by Mowing Height and Foliar Applied Iron

      Kopec, David M.; Gilbert, Jeff J.; Kerr, D.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
    • Growth of Legume Tree Species Growing in the Southwestern United States

      Schuch, Ursula K.; Norem, Margaret; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Vegetative shoot growth of eleven legume tree species growing under field conditions in the Southwestern United States in Arizona were monitored over two periods of twelve months. Species included plants native to the Southwestern United States, Mexico, South America, and Australia. Based on shoot extension and branch differentiation species could be grouped into three categories. Fast growing legumes included Acacia farnesiana, A. pendula, Olneya tesota, Parkinsonia floridum, and Prosopis chilensis. Intermediate growth rates were monitored for A. jennerae, A. salicina, and A. visco. Slow growing species in this study included A. stenophylla, P. microphylla, and P. praecox. No buds, flowers, or pods were observed for P. microphylla, O. tesota, and P. chilensis during the study. Of the remaining species those native to the Americas flowered in spring and those native to Australia flowered in fall or winter.
    • Alternatives for Tree Staking

      Schuch, Ursula K.; Kelly, Jack; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Staking is a common practice following planting of most trees in the landscape. The objectives of this project were to demonstrate four methods of staking trees and the effect on subsequent caliper growth and taper development. Master gardener volunteers were involved in this project. Four methods of staking were used on two different tree species. Acacia stenophylla were 3.1 m tall at planting and were difficult to keep upright with one or two tall stakes. All acacias staked with root stakes or short stakes required corrective pruning to establish a new leader. Prosopis velutina staked with root stakes or short stakes developed greatest taper within 6 months after transplanting. Root stakes will not require removal of staking materials.
    • USGA Distichlis Report University of Arizona Summer 2003

      Kopec, David M.; Gilbert, Jeff J.; Pessarakli, Mohammed; Evans, Phillip; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      The U/A twenty-one clone saltgtrass accession nursery received a mowing height of 7/8" (or less) in 2003. In spring of 2003, clonal accessions C-8, A51, A53, and A138 produced the quickest green-up in early April. Accessions with good quality turf performance in spring/early summer included A138, A51, C-8, A65, A48, and A53. Starting in July, all plots were split with a rolling treatment (850 lb. roller, 2 passes, 2-3 times weekly) up until early October. The main effect of rolling caused increased positive responses for certain clonal accessions, others showed no response, while yet others showed decreased performance from the rolling treatment. Rolling increased positive turf responses among turf clones with showed good turf quality when not rolled. This occurred for nine of the twenty-one clones in this test, all when mowed 3 times weekly at 7/8". Accumulated rolling increased turf performance to enhanced and acceptable levels of quality (6.0 or greater) by the end of September. This was true for nine of the twenty-one clones as well. Accessions, which produced good quality turf (after rolling started in June) throughout the summer, included the following: A138, A65, A86, A137, A48, A51, and A40. Accessions which produced the best quality turfs when unrolled included A138. Likewise, turf density visual scores produced similar accession X rolling interactions. Eleven of the twenty-one clones produced a denser appearing turf after rolling, nine of which had mean visual density scores within the range of 6.3 - 8.7, when rolled. This enhanced response to rolling improved the overall appearance (turf quality) of select clonal accessions over their unrolled counterparts. Initial response to repeated rolling and lower mowing heights showed a favorable response among certain clonal accessions.
    • Nitrogen Requirements of Prosopis Velutina during Early Seedling Growth

      Hahne, Kathryn S.; Schuch, Ursula K.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      The objective of this study was to determine the optimum rate of N to maximize growth of Prosopis velutina seedlings and minimize N leaching when seedlings were grown in different substrates. Mesquite seedlings were grown in sand or soilless media and were fertigated with a solution of67 % NH₄⁺: 33 % NO₃⁻ at a rate of 25, 50, 100, or 200 mg N/L. After 60 days, plants in media produced 41 % more leaves and total biomass compared to those in sand. Leaf number was greatest for plants grown at 200 mg N/L in both substrates. Root biomass of plants in media showed no response to increasing N concentrations while root biomass of seedlings in sand were similar for the three lower N concentrations and nearly doubled for the highest one. Shoot biomass of seedlings receiving 25, 50, or 100 mg N/L was similar, but more than doubled for plants fertigated with 200 mg N/L. N leachate losses were highest from seedlings growing in sand and receiving the two higher N fertigations, those in media had greatest N leachate loss when fertigated at 200 mg N/L.
    • Evaluation of Velocity* Herbicide for Poa annua Control in Turf

      Umeda, Kai; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Two or three applications of Velocity at 30 g ai/A controlled P. annua 63 to 82% in two field experiments. Multiple applications of Velocity at 17 day intervals provided a higher degree of P. annua control compared to applications made at 28 day intervals. At approximately one month after initial applications, Velocity treatments, single or sequential, demonstrated 50 to 77% control of P. annua. The activity on P. annua was minimal at two weeks after initial applications of 30 to 60 g ai/A and slight chlorosis was evident. Perennial ryegrass exhibited chlorosis at two weeks after applications and appeared to recover at one month.