• Field Performance of Selected Mowed Distichlis Clones, USGA Research Report #2

      Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Twenty-one clonal selections of saltgrass (Distichlis spp.) were evaluated during the first full summer growing season (May - October 1999) for turf characteristics and general adaptation. Initial percent plot cover in May ranged from 8% to 42% among clonal accessions. Accessions which produced the highest unmowed canopy heights had the greatest initial cover in May. This trend reversed itself by August and September whereby entries which exhibited less elevated foliage tended to produce turfs which had higher shoot densities, greater percent plot cover, visual estimates of density and more acceptable overall turfgrass quality under accumulated mowing pressure. The "treatment" (clonal accession) affect was significant on all dates for all field variables demonstrating clearly that differences exist for growth parameters of Distichlis screened under mowing stress.
    • Field Performance of Selected Mowed Distichlis Clones, USGA Research Report #4

      Kopec, David M.; Adams, Alan; Bourn, Chris; Gilbert, Jeffrey J.; Marcum, Kenneth P.; Pessarakli, Mohammed; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Clonal accessions (genotype selections) of Distichlis continue to show divergent responses for turf-type growth habit and general turf-type adaptation under field mowing stress. The treatment (clonal accession) affect was significant for all field response variables from mid July to mid August (data collections for Report #4, except for "percent plot straw" on October 12. In July 2000, mean percent plot green cover ranged from 47% to 96% among clonal accessions. Turfgrass quality in July was best among the entries A138, A86, A137, A48, A51, and A40. These entries had the greatest percent plot cover, moderately fine leaf texture, and high shoot density, compared to other entries. In the calendar year 2000, (includes weather conditions in Report #3), the test site was exposed to atmospheric conditions which included a reference ET. of 3.59" (January); 4.42" (February); 6.23" (March); 8.96" (April); 11.32" (May); 9.08" (June); 9.31" (July); 7.53" (August); 7.37" (September); 3.55" (October). The test was subjected to severe drought conditions throughout the test, starting April 2000. Rainfall from January too, and including April was 1.28 inches. There was no rain from May 1 to June 15. Four rains from July 17 to July 30 added 2.94 inches of rainfall, with two thirds of this occurring from one storm on July 29. No irrigation was added from July 1, until September 15. During that time period, 3.26 inches of rain fell in July. In August, 2.47" of rainfall occurred. From June 1 to September 15, the accumulated reference ET. was 29.68 inches. Total rainfall was 5.81" (no irrigation practiced). Most (but not all) Distichlis accessions maintained adequate turf color and percent plot green, up to late August. Visual stress ratings in early August showed differences in visual stress ratings and leaf canopy temperatures measured with a hand held IRT device. Entries A48, A51, A40, A138, A61, and C10 exhibited the least amount of visible drought stress in early August. Accessions that had the highest overall quality ratings in July were A138, A86, A137, A48, A51, and A40. Accessions that exhibited acceptable (highest) turf quality prior to and during the drought period included A138, A40, and A51. Drought induced dormancy finally occurred at the beginning of September, as most accessions drastically decreased the amount of green plot foliage after a prolonged period without irrigation. After flood irrigation and fertilizer applications on September 15 and September 29, plots recovered by mid October. The recovery was not full, as the greatest amount of green percent plot cover ranged from 23% to 83% among entries. Entries with the greatest amount of green cover after the post dormancy period included, A65, A138, A137, A77, and A72. All entries did exhibit reduced quality in comparison to July ratings. Based on these results, Distichlis should be irrigated once/month in a desert condition to avoid drought induced dormancy. During the calendar year 2000, accessions which had notable performance included: Early Spring Green Up: C8, A77, A138, A86; Early Summer Quality (non-water stress in May, and water stressed in June): A55, A86, A51, and A40, A138; Mid Summer Quality: A48, A86, A137, A51, A138; During Drought Quality: A138, A40, A51; Post Dormancy Quality: A65, A138, A137, A77, A72.
    • Overseeding Fairway Trials

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Fifty-one overseed entries were evaluated in 1997-1998 for turfgrass performance. New experimental accessions of perennial ryegrass were darker in color than most of the commercially available germplasm included in this test. Ryegrass germplasm had better turfgrass quality after April, than did mixtures of perennial ryegrass with Poa trivialis, which performed well in December, January and March. General appearance for total plot leaf texture was best generally among the Poa trivialis containing mixtures. Hybrid (or intermediate) ryegrasses (L. which are crosses between perennial X annual ryegrass, are generally closer to annual ryegrass in performance. There was a vast improvement in L. hybridum (Pick YNC) when compared to annual ryegrass alone for turf performance. Intermediate and annual ryegrasses did show signs of decline in June (more so than ryegrass or Poa trivialis blends), which was desirable from a transition standpoint.
    • Initial Investigations of Effectiveness of Cultural Practices to Minimize the Negative Effects of Excessive Thatch on SR1020 Creeping Bentgrass

      Whitlark, Brian S.; Jensen, David; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Increased demand for golf course greens with fast ball speeds and aesthetically pleasing turf present the greatest public pressures that golf course superintendents face today. In the desert southwest, the annual summer monsoon rainfall pattern brings increased atmospheric humidity which results in an increase in the tendency of SR1020 creeping bentgrass to build-up thatch. The effects of four different cultural practices on color, quality, thatch, and ball roll were evaluated on a SR1020 creeping bentgrass green built to USGA specifications grown in an arid environment during a period of increased atmospheric humidity and rainfall. Plots that were verticut/topdress once every two weeks showed unacceptable color, quality, and ball roll. Rolling twice a week had no significant impact on color, quality, and thatch, however, rolling did have a slightly positive impact on ball roll. Grooming three times per week had no significant impact on thatch reduction, and resulted in decreased color, quality and ball speed. Topdressing one time per week did decrease the natural tendency of thatch build-up in SR1020 during periods of increased atmospheric humidity. Topdressing one time per week slightly increased color, quality, and ball roll.
    • Field Performance of Selected Mowed Distichlis Clones, USGA Research Report #1

      Kopec, David M.; Marcum, Kenneth P.; Hughes, Harrison; Christiansen, Dana; Koski, Anthony; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Twenty-one clonal selections of saltgrass (Distichlis) were evaluated in March and May for initial green-up, plot growth, unmowed canopy height, number of satellite plants emerging from rhizomes and floral expression. Accessions were statistically different for all variables measured. Colorado’s accessions (5 of 7) were upright in growth habit and had the greatest number of satellite plants at the surface in March. These plants also had the greatest percent plot coverage. Arizona’s accessions had lower growth in height, were more compact in growth and were less sprawling. However, their plot coverage (grow-in) was not as great as the upright, rapid growing Colorado accessions. Of the twenty-one clones included, thirteen are males and eight are females, with expression ranging from 1 to more than 200 flowering culms per plot.
    • Seed Propagation of Cordia boissieri and Cordia parvifolia

      Schuch, Ursula K.; Davison, Elizabeth; Kelly, Jack; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Cordia boissieri and Cordia parvifolia are plants commonly used in landscapes in the Southwest. Although they are available in the nursery trade, Cordia species are recalcitrant to germinate from seeds. The objective of the study was to determine a reliable propagation protocol for each species. Germination percentages for Cordia boissieri of 70 to 100% were obtained when seeds were stratified under warm conditions before germination. However, with prolonged storage seeds lose viability and age of the seed and seed storage conditions need further investigation. Seeds of Cordia parvifolia collected from local sources had low viability and did not germinate in response to several different seed treatments.
    • Forced Transition of Tifway 419 using Select Cultural Management Practices

      Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      A test was devised to investigate a forced spring transition from perennial ryegrass, back to Tifway (419) bermudagrass with scalping as the main treatment. Scalping of the turf was combined with various nitrogen and aerification treatments performed initially on May 22, 1997. Turfgrass aeration, either with or without extra nitrogen applications, when combined with an initial scalping operation, did not enhance bermudagrass transition by twenty-eight days after treatment (DAT), at the end of June 1997. Turfgrass color, quality and density were adversely affected from initial aerification treatments, especially when combined with initial scalping, The turf recovered best from multiple applications of nitrogen (applied at scalping and again at 7DAT). Turfgrass density (visual estimates) showed that in conjunction with scalping, two applications of nitrogen, totaling 1.5 lbs./month, without aerification, provided a dense turf at 16DAT, which was second only to the untreated control plot. At 27 DAT, scalping + N + N + aerification treated plots had the highest estimate of visual density, eventually showing a benefit from aerification. Scalped and aerified turf alone (no nitrogen) had unacceptable turf density at 16DAT and 27DAT. Generally, two 0.75 lb./N/m applications with aerification proved beneficial over the single application of nitrogen plus aerification, when both turfs were initially scalped. Although non-significant statistically, the additional treatment of nitrogen provided 10% more bermudagrass cover than the single application of nitrogen, for turfs both overseeded and scalped. Scalping alone, plus a single application of N, produced 33% less bermudagrass by June 30, then that of the untreated control.
    • Oxadiazon Applied as a Pre-Emergence for Poa annua with Reference to Fall Overseeding of Bermudagrass Turf

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Ronstar was applied at three rates (1.0, 2.0 and 4.0 lbs. AI/A) at 12, 10, 8, 6 and 4 weeks before overseeding bermudagrass turf with perennial ryegrass on October 20, 1997. On November 7, 1997 (18 DAS) Ronstar treated plots ranged from 20% to 81% for percent plot ryegrass coverage. The greatest mean ryegrass coverage occurred for the 2.0 lbs. rate/@ 12 WBOS. Among the 4 lbs. treatments, there was more or less a linear decrease for ryegrass establishment on a visual plot basis as the application time came closer to the overseeding date. On December 1, Ronstar treated field plots ranged from a low of 29% ryegrass cover (4 lbs./@ 4 WBOS) to 91% (2 lbs./@ 12 WBOS). Among the 4 lbs. treated plots, the 10 and 12 WBOS timing allowed for 82% and 75% mean plot cover respectively, by December 1 (42 DAS). Of the remaining treatments, the 2 lbs./@ 4 WBOS had 61% plot cover (ryegrass) while all other 1 lbs. and 2 lbs. plots had 80% or greater cover at this time. On December 15, 1997 (56 DAS), mean percent plot scores for percentage ryegrass cover ranged from 53% to 100%. The only plot which had significantly less plot cover was 4 lbs./@ 4 WBOS (53%). All other plots had 88% or greater ryegrass cover. Turfgrass color scores showed a significant Atreatment@ effect on December 15, but not on December 29, January 29, March 11 or on April 11. On December 29 (70 DAS), overall turfgrass quality scores ranged from 4.0 (unacceptable) to 7.8. Two treatments which were sub-par included 4 lbs./@ 6 WBOS (5.7 = marginal) and 4 lbs./@ 4 WBOS (4.0 = unacceptable). Treatments which had mean quality values of 7.0 or higher included; 1 lbs./@ 10 WBOS (7.8), 1 lbs./@ 6 WBOS (7.8), 2 lbs./@ 10 WBOS (7.5), 1 lbs./@ 8 WBOS (7.3), 2 lbs./@ 6 WBOS (7.3), 4 lbs./@ 12 WBOS (7.3) and 2 lbs./@ 12 WBOS (7.3). Weed pressure was inadequate to fully assess pre-emergence control of Poa annua. At the close of the test on April 11, 1998, weed control ranged from 8% to 100%. Plots with 90% or greater weed control included 2 lbs./@ 10 WBOS, 1 lbs./@ 4 WBOS, and 4 lbs./@ 12, 8, 6, and 4 WBOS. The 1.0 lbs. AI/A treatment was safe for perennial ryegrass at 12, 10, 8, 6, and 4 WBOS. The 2.0 lbs. AI/A treatment was safe for perennial ryegrass at 12, 10, and 8 weeks. The 4.0 lbs. AI/A treatment was safe at 12 and 10 WBOS.
    • The Potential use of Sulfentrazone for Poa annua Pre-emergence Control at Overseeding

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Sulfentrazone herbicide was applied to bermudagrass turf, prior to overseeding at 0.125, 0.250 and 0.375 lbs. AI/A. Sulfentrazone did not inhibit emergence of perennial ryegrass when applied two days before overseeding. Plots ranged from 92-100% cover (of perennial ryegrass) from December to the end of March (last evaluation). Turfgrass color was noticeably less at the 0.375 lb. AI/A rate, but not significantly different from that of the lower rate application treatments. Pre-emergence weed control based on non-overseeded controls ranged from 51-100% across Sulfentrazone treated turfs, from December 1996 to late March, 1997. The percent reduction in Poa annua due to overseeding (comparison of non-overseed vs. overseed controls) was 90%, 61% 67% and 65% in December, January, February and March, respectively. Initial screening shows favorable activity for Poa annua control, especially at the 0.375 lb. AI/A rate. Further evaluation is needed to assess Poa annua suppression from Sulfentrazone and its potential interaction with overseeding, before cultural management programs can be devised for Poa annua control in an overseed program.
    • Response of Tall Fescue to R.P.-EXP31130A and R.P.-EXP31598A

      Kopec, David M.; Gilbert, Jeffrey J.; Kerr, Darren E.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      EXP31130A and EXP31598A were applied as repeat applications on June 5 and July 23, 1997 to tall fescue turf maintained at 3.0 inches. Application rates were 0.18 and 0.36 lbs. AI/A (31130A) and 7.0 and 14.0 fl. oz/prod/A (31598A). Each treatment was applied with and without Sequestrene 338 iron chelate, at the rate of 0.1 oz/m ². Untreated and iron-only controls were included in the test. Neither herbicide compound (either with of without iron) caused discoloration, leaf tip burn, sheath necrosis, or blotchy colored turf at the rates and timing applications performed here for low maintenance tall fescue under desert summer conditions. EXP31598A herbicide, when applied without iron to tall fescue turf, exhibited acceptable levels of turfgrass color at all times when applied at the 7 ounce/prod./acre rate. EXP31598A herbicide, when applied without iron to tall fescue turf, exhibited a lighter, but acceptable color turf, when applied at the 14 ounce/prod./acre rate. When iron was added, the 14 ounce/prod./acre rate of EXP31598A produced in general, a slightly darker turf than the same compound at the 7.0 ounce/prod./acre rate. Improved turf color resulted from the addition of iron at 0.1 ounce/m ² for tall fescue treated with EXP31130A. This occurred more so for turf treated at the low rate (0.18 lb. AI/A) than for turf treated at the high rate (0.36 lb. AI/A). The addition of iron to EXP31130A did not increase overall quality at either application rate of the herbicide. When iron was added (0.1 ounce/m ²), turfgrass quality was improved for EXP31598A, especially at the high application rate of 14 ounce/prod./acre.
    • An Update on Termiticide Degradation in Arizona Soil

      Baker, Paul B.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Termiticide applications are the standard practice in the pest control industry to protect structures from the invasion of termites. However, information related to termiticide persistence is lacking. In 2 field trials, soil residues analysis were carried out to determine degradation among existing and candidate termiticides in 3 different chemical classes. Plots were established to simulate industry standards for the application of termiticides. Study 1 termiticides tested were Dragnet FT (permethrin, 0.5% and 0.25%;), Prevail FT (cypermethrin, 0.25%;), Biflex FT (bifenthrin, 0.06%;), Fury TC (zeta-cypermethrin, 0.125%;) Premise 75 (imidacloprid, 0.05%,), Dursban TC (chlorpyrifos, 1% and 0.75%) and the untreated check. In Study 2 termiticides tested were DeltaGard SC (deltamethrin 0.075%, 0.125% and 0.25%); Dragnet FT (permethrin 0.5%;)and the untreated checks. In study 1, in general, all termiticides showed more degradation in the exposed plots than those covered by the concrete slab. In the exposed plots, specifically in the 4th year, four of the eight treatments had no residues In comparison, the covered plots had only 1 treatment, with no residues. In general the pyrethroids of permethrin at 0.25% and 0.5% along with bifenthrin at 0.06% held up longer than the organophosphate chlorpyrifos or imidacloprid the chloronicotinyl compound. Study 2, after one year, the exposed plots showed a slightly greater degradation than the covered plots. However, due to plot-to-plot variation no conclusions can be drawn from the data, other than the permethrin plots showed less than 40% remaining in any plot.
    • Sulfentrazone Effects on Purple Nutsedge

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Sulfentrazone was applied to a highly infested purple nutsedge groundcover as either single or double combination (split) applications for initial evaluation for weed control during the summer of 1996. One time single applications at 0.125 lb. AI/A resulted in 15% or less control, from 10 to 64 days after treatment (DAT). Nutsedge control from 0.25 lb. and 0.38 lb. AI/A treatments were not significantly different from each other (ranging in 10% difference or less) but was greater than the low rate 0.125 lb. AI/A. Single applications of imazaquin and halsulfuron (at known label rates) had better control than sulfentrazone at the rates tested here when tested as single applications. Single applications at 0.50 lb. AI/A appear warranted for sulfentrazone. Split (multiple) applications greatly enhanced the activity of Sulfentrazone at the two higher split rate treatments, both which resulted in a total application of 0.50 lb. AI/A total. The 0.375/0.125 split application had slightly better control than the 0.250/0.250 split treatments. Split applications of imazaquin or halsulfuron at known label rates resulted in slightly higher control. All plots experienced re-growth. Based on these results, sulfentrazone does have activity against purple nutsedge. Additional treatments in a new and different rate structure appear warranted to increase initial control and longevity of effect.
    • Ethephon Potential for Spring Transition of Perennial Ryegrass back to Common Bermudagrass

      Kopec, David M.; Jensen, D. P.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Spring transition of ryegrass back to the underlying bermudagrass has become problematic for turfgrass managers in the Southwest. This is in part do to increased heat tolerance and shoot densities of newer ryegrass cultivars which predominate the market place. The chemical ethephon (Proxy for turf) was evaluated for use as a plant growth regulator (PGR) to enhance transition from perennial ryegrass to bermudagrass. Proxy was applied at either 5 or 10 ounce rates/1000 square ft, either before, during or after soil moisture stress was imposed on the overseeded turf. On the dates of July 6, 21, 19 and August 9 the greatest visible difference occurred among treatments for percent bermudagrass. These responses were not not statistically significant, however. The greatest transition response was achieved (in general) from Proxy applied at 10 the ounce rate, when applied "pre-stress". This treatment combination generally ranked highest for percent bermudagrass throughout the test. The second most beneficial treatment (in general) was that of Proxy at the 10 ounce rate when applied under "medium stress". From July 21 to August 9 this treatment essentially ranked second for the ryegrass to bermudagrass transition. The third most beneficial treatment (in general) was Proxy applied at the 10 ounce rate , applied "post stress". This treatment was applied the latest in the season ( June 16), which was 22 days after the entire test was fully irrigated (at the start of the test on May 23). Proxy applied "post stress" at the 10 ounce rate excelled in enhancing the ryegrass to bermudagrass transition from July 21 to July 29. When applied at either the 5 or 10 ounce product rates, the "low stress" application treatments had minimal affect for transition. These treatments ranked similar in response to that of the untreated - well watered controls. The "medium" stress plots receiving Proxy exhibited a greater affect on the ryegrass to bermuda transition, depending on the date of bermudagrass evaluation. Further testing should be conducted on lower mowed perennial ryegrass with a more aggressive underlying bermudagrass base, such as the popular Tifway 419.
    • Evaluation of Timing Applications of Ethephon and Trinexepac-Ethyl for Seed Head Suppression of Poa annua

      Kopec, David M.; Gilbert, Jeffrey J.; Pessarakli, Mohammed; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      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.
    • Response of Poa annua to Post-Emergence Application of Sulfentrazone Herbicide

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Poa annua (annual bluegrass) is a major weed problem in winter turfs. It is a cosmopolitan and well adapted weed in most turfgrass settings. Cultural management programs to control or eliminate Poa annua are either limited or unsuccessful. Sulfentrazone herbicide was applied to perennial ryegrass turf (as overseeded bermudagrass) which had high levels of Poa annua infestation (45%-75%) at 0.125, 0.250 and 0.375 lb. AI/A. There was essentially a limited response of Poa annua to Sulfentrazone at these rates when applied on March 7, 1997. EMBARK LITE (Mefluidide) was applied once at 0.125 lb. AI/A and caused some initial discoloration to the turf at 10 DAT. At 25 DAT percent control of Poa annua (seed heads) reached 90% or greater which declined to 58% on April 15 (40 DAT). Turfgrass color was enhanced from the single application of Mefluidide at 25 and 40 DAT on golf course rough turf maintained at a mowing height of 1.50 inches. Sulfentrazone exhibited minimal or no effect on Poa annua when applied as a post emergence treatment.
    • Summer Applied Pre-Emergence Herbicides to Prevent Poa annua Emergence on Fall Overseeded Turf

      Kopec, David M.; Gilbert, Jeffrey J.; Jensen, D. P.; Bates, Michael; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Ronstar and Barricade herbicides were applied to bermudagrass prior to overseeding with perennial ryegrass. For the initial establishment of fall overseeded bermudagrass with perennial ryegrass, Barricade and Ronstar both showed decrease in establishment at thirty days after overseeding (October 26) when compared to the controls. Reductions in turfgrass density after overseeding were realized by all pre-emergence treatments in the mid to late fall, depending on the specific treatment. Ronstar applied in one application at 2.0 lbs AI/A noticeably reduced visual density at 30 and 65 days after overseeding, regardless of the application timing ( 6 vs. 8 weeks) before overseeding. Reductions in turfgrass quality paralleled the reduction in density. Barricade applied at 0.75 lbs AI/A at 6 WBOS showed decreased quality at 30 and 65 days after overseeding. This same treatment caused a noticeable decrease in overall plot density at thirty days after overseeding. At 65 days after overseeding (November 30), quality was not quite fully acceptable (quality mean = 5.8), but acceptable density was achieved (mean density = 6.3). Poa annua (PA) established itself quickly. By November 30 (65 days after overseeding) overseeded- untreated control plots had between 67%-77% Poa annua present. The maximum rate of PA control for Ronstar in March was 74% (showing 15% Poa plot cover) and 61% in April (34% Poa plot cover). This occurred for the 2.0 lb AI/A at 8 WBOS treatment, which was similar to the same rate applied 6 WBOS. Split sequence applications (pre and post) of Ronstar produced low PA control (28%-50%) over the season as measured, when compared to single applications which achieved the same 2 lbs AI/A rate. The greatest amount of PA control was achieved by Barricade applied at 0.75 lb AI/A at 6 WAOS (86%-94% control). No treatment achieved 95% control of PA on a season long basis. Poa pressure at the test site was uniform and heavy.
    • Dimension Herbicide as a Potential Product for Pre-Emergence Pos Annual Control on Overseeded Bermudagrass Turf

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Dimension herbicide (dithiopyr) was applied to common bermudagrass turf at 90, 60, and 45 days before fall overseeding to measure the efficacy for turf safety and for control of fall germinating POA Annua (PA). Applications were made at 0.25, 0.375, and 0.50 lbs. AI/A on each date. One half of each plot was overseeded, while the other half was not. Percent plot (PA) infestation and percent weed control was more greatly affected by the process of overseeding, than that of the herbicide applications alone. When not overseeded, the bermudagrass turf had a maximum of 45% PA control in November, which decreased dramatically to little or no control from January to March 2000. With the inclusion of ryegrass overseed, the high rate (0.50 lbs. AI/A) applied closest to the overseeding (45 DBOS) provided between 79-82% PA control over the length of the test. Actual infestation levels among non-chemical receiving control plots showed a 3X increased level in PA suppression due to overseeding, when compared to the non-overseeded, non-chemical controls. Dimension herbicide alone had little effect for PA control. When combined with overseeding, the 0.50 lb. AI/A rate, applied at 60 or 45 DBOS provided the greatest levels of PA control. The performance of Dimension on non-overseeded bermudagrass does not support the anticipated use of this chemical for PA control.
    • Influence of pH 11 Water on Termiticide Degradation in Arizona

      Baker, Paul B.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Termites continue to be Arizona’s number one urban pest. Factors that influence the persistence of termiticides are constantly under investigation. High pH has been identified as a potential concern for persistence in termiticides. I studied the influence of pH 11 water on five termiticides applied to commercial ABC fill 10 months post-treatment. In general, the addition of pH 11 water had little influence on termiticide persistence under Arizona conditions. Initially plots treated with Ph 11 water had higher residues than those that did not receive the treated water; over time these differences diminished.