• Growth Responses of Desert Saltgrass under Salt Stress

      Pessarakli, Mohammed; Marcum, K. B.; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Saltgrass (Distichlis spicata), clonal accession WA-12, collected from Wilcox, Arizona was studied in a greenhouse to evaluate its growth responses in terms of shoot and root lengths, shoot fresh weight, and shoot and root dry weights under control and salt (sodium chloride) stress conditions. Plants were grown under control (no salt) and three levels of salt stress (100, 200, and 400mM NaCl equivalent to 6250, 12500, and 25,000 g Lᴮ¹ sodium chloride, respectively), using Hoagland solution in a hydroponics system. Plant shoots (clippings) were harvested weekly, oven dried at 60 °C, and dry weights recorded. At each harvest, both shoot and root lengths were measured and recorded. At the last harvest, plant roots were also harvested, oven dried, and dry weights were determined and recorded. The results show that the shoot and root lengths decreased with increasing the salinity levels, however, both shoot fresh and dry weights significantly increased at 200mM NaCl salinity compared with the control or the 400mM NaCl level. Root dry weights at both 200mM and 400mM NaCl salinity levels were significantly higher than the control.
    • 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.
    • 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.
    • Ryegrass Germplasm Overseeding Trials

      Kopec, David M.; Gilbert, Jeffrey J.; Jensen, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      A field test was conducted to evaluate the turf performance of improved hybrid ryegrass (sometimes called intermediate ryegrass) Lolium hybridum versus that of perennial ryegrass germplasm (Lolium perenne) for winter overseeding purposes. "Gulf" annual ryegrass was also evaluated for comparison purposes. On all evaluation dates, the treatment effect was significant for all visual response variables measured (quality, color, texture, density, etc.). The mixture of LHRT hybrid ryegrass/Poa trivialis established quicker than other treatments during the first month (November). Perennial ryegrass entries provided the darkest color turf. Among hybrid ryegrasses, Pick A-97 was slightly darker in turf color when compared to LHRT. LHRT alone was darker in color than when mixed with Poa trivialis. In terms of overall turf quality, Pick A-97 and LHRT hybrid ryegrasses were essentially equal in performance. The spring decline was greater among hybrid ryegrasses than that of perennial ryegrass. Both hybrid ryegrasses (A-97 and LHRT) were superior to annual ryegrasses in all aspects of turf performance. By mid-June of 1999, Pick A-97 had more bermudagrass present (52%) than LHRT (28%). LHRT had more straw-colored (dead transition grass) than A-97 as well. By early July, A-97 and LHRT had 72% and 62% bermudagrass, respectively, and essentially the same amount of overseed present (20-23%). LHRT had 15% plot straw at this time, while A-97 had 8%. Among perennial ryegrasses, Sunshine had the slowest transition (42%), followed by Jiffie (50%) and Future 2500 (71%) by early July. The addition of Poa trivialis to LHRT hybrid ryegrass increased overall quality of the LHRT alone, but slowed transition slightly, most likely due to increased canopy densities achieved by the addition of Poa trivialis. This test demonstrated that the hybrid ryegrass germplasm tested here provided adequate fairway turf performance, and that transition among and between Lolium germplasm is variable, and genetically dependant.
    • The Effects of Pre-Emergence Applications of Sulfentrazone Herbicide and Perennial Ryegrass Overseeding of Poa annua Infestation of Winter Turf under Desert Conditions

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Poa annua or annual bluegrass is a cosmopolitan winter annual weed in turfgrass systems. A field test was conducted to evaluate the effects of sulfentrazone herbicide, both with and without the fall overseeding practice on bermudagrass in the desert. Sulfentrazone was applied three days before overseeding at 0.125, 0.187, 0.25, 0.375, 0.5 and 0.625 lbs.AI/A. Percent Poa infestation levels were dramatically less on overseeded (perennial ryegrass added) turf throughout the entire test period than non-overseeded (dormant bermudagrass) turf. For non-overseeded turf, sulfentrazone provided a maximum of 74% weed control at November 1997, 68% in December, and 25% by March 1998 at the highest application rate of 0.625 lbs./A. For overseeded (perennial ryegrass) turf, the highest level of weed control was achieved for sulfentrazone at the 0.625 lbs./A rate, which was 68% in April. The practices of overseeding and sulfentrazone applications provided the greatest weed control, however, different rate/timing regimes should be investigated to increase efficiency.
    • Response of Perennial Ryegrass under Desert Conditions to Applications 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)
      Sulfentrazone was applied to perennial ryegrass turf as single applications at 0.125, 0.250 and 0.375 lb. AI/A, and split application combinations of 0.125/0.125, 0.250/0.250 and 0.375/0.125 AI/A. Respective treatments were applied on June 28 and July 31, 1996. Sulfentrazone caused a decrease in turfgrass color, which was most noticeable at the 0.375 lb. AI/A rate. Decreases in color were generally dependent on application rate. Sulfentrazone caused a slight "pocking" of the turf, which resulted from leaf twisting/cupping. This injury was most evident at seven days after the first application. There was no foliar burning or uneven discoloration however. The turf exhibited a lesser amount of discoloration and injury following the second (split) application.
    • Control of Wild Celery in Low Maintenance Bermudagrass Turf.

      Kopec, David M.; Jensen, David M.; Gilbert, Jeffrey J.; Liddel, Steven B.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Herbicides applied for post-emergence control of wild parsley differed in turf injury and weed control. All products tested required multiple applications (21 days apart) to attain acceptable weed control levels. Weedone (2, 4-D) has the quickest, highest, and longest lasting amount of weed control. Weedone (2, 4-D) caused minimal injury to the common bermudagrass turf. Bromoxynil at the low rate of 2.0 lbs. ai/a caused minimal injury to the turf, but provided low levels of weed control. Bromoxynil at the high rate of 3.0 lbs. ai/a caused considerable injury to the turf and moderate to high weed control for about one month, followed by weed recovery. MCPP caused slight initial injury to common bermudagrass and moderate to good weed control (71%-92%) from 7 to 35 days after the second treatment. Weed control was slower to achieve than that of the Weedone treatments. Confront herbicide (trichlopyr and clopyralid) caused slight to moderate initial injury to the turf (more so at 2.0 than at 1.0 pint/product/acre) as well as noticeable necrosis and decreased color of the common bermudagrass up to 21 days after the second application. Confront at the 2.0 pint/acre rate reached weed control levels of 90%-97% at 21 and 35 days after the second application, respectively. At the low rate of 1.0 pint/acre, a maximum of 83% weed control was achieved at the close of the test. Quadmec (applied three weeks later at each respective application date than all other treatments) produced moderate necrosis in the bermudagrass after the initial application, which eventually recovered. However, the turfgrass color was lower in rank (lighter) than most other treatments and was similar to that of the untreated controls. Quadmec achieved 96% control by the close of the test on July 2, 1999 (14 days after the second application). All treatments include 0.5% v/v Silwet surfactant. When applied alone, Silwet produced a small level of weed control, which peaked at 36% at 14 days after the second treatment.
    • Response of Tall Fescue Turf to Applications of Sulfentrazone

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Applications of sulfentrazone were applied to 2.75" mowed tall fescue under hot-humid desert conditions to assess post application response. A uniform decrease in color occurred shortly after application at the 0.375 lb. AI/A rate. The effect was short lived and tended to be minimal in split application treatments. Leaf cupping/twisting was exacerbated from applications of sulfentrazone, especially at the 0.375 lb. AI/A rate. At 0.125 and 0.250 lb. AI/ rates, the leaf cupping was much less noticeable. Percent plot showing the leaf cupping symptoms was also rate dependent and generally ranked with degree of effect. Leaf cupping dissipated rapidly after 14 days after treatment. Color changes were minor, while leaf cupping was the more noticeable symptom response on tall fescue from applications of sulfentrazone.
    • Drought Tolerance of Twenty one Saltgrass (Distichlis) Accessions Compared to Bermudagrass

      Pessarakli, Mohammed; Marcum, K. B.; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Fourteen (14) Arizona accessions and 7 Colorado accessions of Saltgrass (Distichlis spicata), collected from Arizona and Colorado and 1 Bermudagrass (Cynodon dactylon), cultivar Midiron (check), were studied in a greenhouse to evaluate their growth responses in terms of shoot dry weights and percentage of visual green under drought stress conditions. Plants were grown under normal (daily watering and weekly fertilizer application) for one year for complete establishment. Then, the plants were deprived from water for four months (January 5, 2001 - May 5, 2001). Plant clippings were harvested weekly, oven dried at 60 °C, and the dry weights were recorded. At each harvest, percentage of green cover were also estimated and recorded. After the last harvest, plants were re-watered to assess and compare the percent of recovery. Overall, the results (both shoot dry weights and the percent of the visual green) show that the A138 and A137 (Arizona accessions) were the best accessions and the C66 (Colorado accession) was the worst. Both the shoot dry weights and the percent of visual green cover decreased as the drought period progressed. In general, most of the saltgrass accessions were more tolerant to drought stress than the bermudagrass.
    • Creeping Bentgrass Turf Responses to Summer Applied Fungicides

      Kopec, David M.; Gilbert, Jeffrey J.; Jensen, D. P.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Creeping bentgrass is seasonally stressed from high summer temperatures and high humidity conditions in the desert southwest from June to mid-September. Golf greens typically show decreased stand density and poor performance by the end of this time. A preventative fungicide application program was evaluated for the prevention of summer stress typical under summer conditions. Four tank mixes composed of Alliete Signature mixed with either Chipco 26019, EXP10790A, EXP10702B, or Daconil Ultrex fungicides were applied every fourteen days from June 10 to September 17, 1997, on a 'Penncross' creeping bentgrass green maintained at 5/32". The Daconil Ultrex tank mix caused some initial injury and in general, the lightest turfgrass color and the lowest turfgrass quality. EXP10702B treated turf produced, on average, the darkest turf with the leading rank score for quality. The Chipco 26019 tank mix produced the largest seasonal clipping totals, which was greater than the check. No diseases occurred on treated or untreated turf. Root dry weights in mid-October varied as much as 40% among treatments, but was not statistically significant.
    • Overseed Greens Trial 1997-1998

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Perennial ryegrass germplasm was quicker to establish plot cover on a "Tifgreen" bermudagrass green than that of Poa trivialis when used alone. Poa trivialis alone produced lighter color turfs when compared to perennial ryegrass. Turfgrass color was generally uniform in appearance, however, within each entry. Therefore, color as a selection criteria is a matter of choice by the user. The turfgrass mixture "Catalina/Winterplay" (80% perennial ryegrass/20% Poa trivialis) was intermediate in turfgrass color. "Brightstar II" PR generally produced a dark turf throughout the growing season. For overall turfgrass quality, the perennial ryegrasses generally out performed the Poa trivialis germplasm. The mixture of "Catalina/Winterplay" produced a very dense turf, followed closely by "Turfstar Plus" PR, "95-1" PR and "PT-4" PT. ASnowbird@ PT had the least amount of living ground cover by May 31, which is desirable from a transition standpoint.
    • Response of Creeping Bentgrass to Sulfentrazone Herbicide under Putting Green Maintenance Conditions

      Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Sulfentrazone herbicide was applied to a SR1020 creeping bentgrass putting green (5/32") on October 15, 1996 and again on March 4, 1997 at the rates of 0.125, 0.250 and 0.375 lb. AI/A. Betasan was included at the standard rate of 5.6 ounces of product/1000 ft2. Turf response to sulfentrazone was mostly linear with application rate, with higher application rates causing more damage to the turf. Responses occurred quicker in the fall (by 3 DAT) compared to late winter (7DAT). Magnitude of injury was also somewhat less in the late winter than in the fall, although rank responses were still rate dependent for sulfentrazone treated creeping bentgrass turf. Applied rates of 0.250 and 0.375 lb. AI/A were deleterious and not acceptable for putting green quality turf. A marginal (acceptable) response occurred overall at the 0.125 lb. rate. Betasan applied at 5.6 ounces product/1000 ft², caused no visible damage to the turf in the fall and was similar in response to sulfentrazone in the spring at the 0.125 lb. AI/A (repeat) application rate.
    • Response of Common Bermudagrass Turf to Applications of Sulfentrazone

      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 in single applications at the rates of 0.125, 0.250 and 0.375 lbs. AI/A, and after 30 days in split rate combinations of 0.125/0.125, 0.250/0.250 and 0.125/0.375 lbs. AI/A. Turfgrass color scores were slightly diminished form sulfentrazone characterized by a lighter uniform color change on mowed common bermudagrass. The response was generally rate dependent. Imazaquin caused a light green turf to develop while halsulfuron had no effect. After the first application was made, sulfentrazone treated turfs exhibited leaf twisting/cupping effects at 3 and 7 days after treatment. The degree of effect was also rate dependent. To the lay person, twisting was noticeable only for a short time at the 0.375 lb. AI/A rate. At two weeks after treatment, there was a trace amount of leaf sheath necrosis at the base (older leaves) of common bermudagrass stolons. This was negligible and short lived. At the rates tested in this initial preliminary test, it appears that common bermudagrass seems to be tolerant of sulfentrazone.
    • Field Performance of Selected Mowed Distichlis Clones, USGA Research Report #3

      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)
      Twenty-one clonal (genotype) accessions of Distichlis are being continually evaluated for field performance as replicated mowed turf plots under desert conditions. The genotype ("treatment") affect was significant for most field variables measured, or assigned to plots using visual rating scales customary for turf evaluations. Genotype differences occurred for percent plot composition color, quality, texture, uniformity and leaf width. Visual stress (prolonged hot weather without irrigation) and leaf hair presence were not significant responses between accessions. Long term mowing stress shows divergent performance amount Distichlis germplasm for growth characters and turf persistence under mowed conditions.
    • Fairway Overseed Turfgrass Trials, 1996-1997 Season

      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)
      Twenty-three overseed entries (and a non-overseed check) were evaluated from November 1996 to June 1997 for turf performance over Tifgreen (328) bermudagrass. Entries varied for turfgrass establishment, color, quality, density, texture and uniformity on all evaluation dates. One annual ryegrass and three intermediate ryegrass Lolium hybridium entries were included. The intermediate type 'Hybrid X-NC' had better performance than 'Froghair' or 'Hybredium' intermediate hybrids in most cases, except for early transition. Entries which consistently had the darkest green genetic color included 'Citation III', 'LPQ-N3', 'EP-20', 'Charger II', '84-91', 'WX-140', and 'Roadrunner'. Entries which consistently ranked high in overall turfgrass performance included 'Citation III', '2-DLM', '84-91', 'Roadrunner', 'Charger II', 'WX-140', '93-7', and 'LPQ-N3'.
    • Comparison of Two Rates and Two Formulations of Imazaquin for Control of Purple Nutsedge

      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)
      Purple nutsedge (Cyperus rotundus) is a major warm season weed in turfgrass, landscape and agricultural settings. It’s long term persistence is achieved in part by (1) the production of tubers with numerous growing points (2) the ability to produce multiple plants from basal bulbuls at the soil level and (3) the tolerance to defoliation and/or soil cultivation. In turf, purple nutsedge can tolerate almost any mowing regime, and is competitive (in it's growth habit) with turfgrasses. Imazaquin (IMAGE) herbicide has been commercially available in the turfgrass market for almost 12 years for use in warm season turfgrasses for the control of purple nutsedge. Research conducted in the late 1980's at the University of Arizona showed that Image (EC formulation) provided adequate control of purple nutsedge when (1) multiple applications were applied 25 days apart (2) at the 0.50 lb. ai./a rate. In this scenario 98% nutsedge control was achieved (on 100 % nutsedge plots, mowed weekly at 2.5 inches). Repeat applications were still necessary after regrowth (presumably from growing points from underground nutlets). These results were achieved using the 1.5 EC (emulsifiable concentrate formulation). A new test was conducted in 1999, evaluating both the 1.5 EC and 70 DG (dispersible granule) formulations applied at two rates (0.375 lb. ai./a. and 0.50 lb. ai./a). Mean percent weed control on the three evaluation dates of August 17, August 29 and September 16 ranged from 25% to 32%, 50% to 68% and 55% to 75%, respectively. These dates represent the time intervals of 18 DAT/1, 30 DAT/1 and 17 DAT/2. On all three evaluations dates (where measured), the degree of injury, color and percent nutsedge infestation level was significant for the overall "treatment" effect at P=0.05, or less. (Tables 1,2). Actual percent weed control (based on the mean of control plots) was significant on August 29 (30 DAT/1) and on September 16 (17 DAT/2:47 DAT/1). Maximum weed control of 75% was achieved by the EC @ 0.50 lbs. ai./a. at 17 days after the second application. Percent weed control for the DG @ 0.50 lbs. ai./a. was greatest (61%) at that time also.
    • Evaluation of Proxy and Primo for Growth Reduction in Perennial Ryegrass

      Kopec, David M.; Jensen, D. P.; Liddell, Steven B.; Gilbert, Jeffrey J.; Marcum, K. B.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      PROXY (ethephon) and PRIMO (trinexepac-ethyl) were applied to ryegrass (as overseeded turf) in winter and early spring of 1999. PGR effect was assessed as reduction in clipping weight between mowings on eleven harvest dates. From March to April, the greatest percentage reductions were realized from all PGR treatments. Over the entire test period (March 5 to May 15), clipping reduction was rate dependent for PROXY with the 10.0 ounce rate producing a greater PGR effect (less clippings than that of PROXY at the 5.0 ounce rate). PRIMO treated turf (at the highest label rate of 1.0 ounce/product/1000 ft) generally produced the greatest clipping reductions, but lost affect in the middle of May when suppression (broke) was released. PROXY at the 10.0 ounce rate was closer to that of PRIMO for PGR effect than was PROXY at the 5.0 rate. All treatments produced less clippings than that of the control on nine of the eleven harvest events. PRIMO produced on average a noticeably darker color turf than PROXY treated turfs and that of the control plots as well. PROXY treated turf at the 10.0 ounce rate generally had similar overall quality turf when compared to PRIMO treated turf throughout the test. This was due to a high degree of plant uniformity among PROXY treated turf, versus the darker color enhancement realized from PRIMO. No PGR affected the initial stages of spring transition from ryegrass to bermuda by late May 1999.
    • Green-Up of Dormant Bermudagrass after Applications of Early Spring Pre-Emergence Herbicides

      Kopec, David M.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Six treatments of pre-emergence herbicides were evaluated for their effects on the spring green-up of dormant non-overseeded bermudagrass turf. Plot composition (percent yellow, percent green, percent straw or dormant turf) components were affected by herbicides to various extents on March 27, April 20, and April 27. Percent plot yellow turf was least in occurrence for BARRICADE, PENDULUM, and SURFLAN at 25 days after the first treatment. At 25 days after the first application (March 27) PENDULUM produced the lowest amount of green turf (13%) among treated turfs. At 50 days after the first application (April 20) PENDULUM treated turf had the greatest amount of yellow turf (63%), and the least amount of green turf present (18%). Turfgrass color was affected by herbicide treatments (on June 2, 30 days after the second treatment). The TEAM-PRO product had the darkest noticeable turf at this time. Herbicides had no affect on: A) visual estimates of turfgrass density B) number of lateral (horizontal) green stolons in the turf mat C) number of subterranean rhizomes D) root pegging of surface stolons. Green-up responses were short-lived from the herbicides evaluated at product rates tested.
    • Cultural Management for Height Reduction of Tifgreen 328 Bermudagrass Greens

      Kerr, Darren E.; Kopec, David M.; Ruhl, Todd E.; Gilbert, Jeffrey J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Tifgreen bermudagrass (328) has been used for greens in the Southwest for 40 years. Decreased mowing heights desired for tournament events can result in loss of turf quality and performance. A series of mowing and rolling events were devised and executed on a Tifgreen turf mowed at 5/32", in order to minimize the potential negative affects of a reduced mowing height of 1/8". All treatments were executed prior to mowing the turf at the new reduced height of 1/8". Significant treatment effects resulted from combinations of mowing and rolling for ball speed distance, when averaged over three evaluation dates. When averaged over all three evaluation dates, the single mow/no roll treatment [1x mow/0 roll] had the least ball roll distance (BRD) values. Mowing/rolling combinations which resulted in either three or four operations on Day 1 (1x mow/2x roll, 2x mow/2x roll and 2x mow/1x roll) had slightly greater BRD values than the operations which included two operations (2x mow/0x roll and 1x mow/1x roll). BRD values decreased from Day 1, Day 2 and Day 4 from 81.2", 80.3" to 73.4", respectively when average over all treatments. Single mowing at 5/32", followed by either a double or single rolling event prior to mowing to the new height of 1/8" on Day 1, resulted in the longest BRD values for Days 1 and 2. The effect of all cultural management treatments was diminished by Day 4.
    • Response of Perennial Ryegrass to R.P.-EXP31130Aand 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 perennial ryegrass 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/m². Untreated and iron-only controls were included in the test. Ryegrass was generally unaffected by either compound, under the conditions of this test. Inclusion of iron (in the tank mix) was more beneficial for EXP31598A, than for EXP31130A. Untreated controls generally had lower performance scores, than did turf which received either herbicide compound. Treatment effects for overall turfgrass quality were significant only on three of ten evaluation dates, and on one of ten evaluation dates for turfgrass color. In general both compounds appear safe to use on high cut perennial ryegrass turf under summer conditions in a desert environment.