• Scotts Contec Fertilizer Study - 1998

      Gilbert, Jeff J.; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Three slow release fertilizers were evaluated (Contec O.M. Scotts) for turfgrass performance on an overseeded Tifway bermudagrass green from May to October 1998. Products were applied on four dates at the rate of 0.5 and 1.50 lbs. actual -N- per thousand square feet. All fertilizer regime showed little response from June-July for turfgrass clippings, color and quality. After July, differences in color and clippings were detected on X out of X evaluation dates. In general, release/conversion responses occurred approximately one month after application. When coupled with subsequent series applications, the combination of released nitrogen with the water soluble component (approximately 10%) caused the greatest turf response. Clipping production was greatest for the X at the rate of X. Transition from ryegrass to bermudagrass was not affected by fertilizer rate. Additional rates should be tested to investigate seasonal performance of these fertilizers on bermudagrass turfs.
    • 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.
    • Spring Transition of Tifway (419) Bermudagrass as Influenced by Herbicide Treatments

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      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 reestablishment 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.
    • 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.
    • 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.
    • 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.