• 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.
    • Growth Responses of Zoysiagrass Influenced by Different Rates of Bio-Turf-Pro

      Pessarakli, Mohammed; Kopec, David M.; Berry, Sarah C; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Zoysiagrass (Zoysia spp.), cv. El Toro was used in this experiment to evaluate its shoot growth in terms of length and dry weight under control and different levels of Bio-Turf-Pro applications in a pot study. Four treatments [Control (no Bio-Turf-Pro), 8 Fl Oz/Gal (½ the recommended rate) per 1000 ft², 16 Fl Oz/Gal (recommended rate) per 1000 ft², and 32 Fl Oz/Gal (twice the recommended rate) per 1000 ft² of Bio-Turf-Pro], and six replications of each treatment were used in a RCB design in this investigation. Plants were allowed to grow under the above treatment conditions for eight weeks. Plant shoots (clippings) were harvested bi-weekly for the evaluation of the dry-matter production. At each harvest, shoot lengths were measured and recorded and the visual growth was also evaluated before the harvest was made. The harvested plant materials were oven dried at 60o C and dry weights were measured and recorded. The shoot growth (length) was stimulated under any levels of Bio-Turf- Pro application rates compared with the control. Among the treatment rates, the 16 Fl Oz/Gal (the recommended rate) per 1000 ft²] numerically stimulated the shoot length the most. However in most cases, there was not statistically significant differences detected among the 8 (½ the recommended rate) per 1000 ft², 16 Fl Oz/Gal (the recommended rate) per 1000 ft²] and the 32 Fl Oz/Gal (twice the recommended rate) per 1000 ft²] application rates of the compound on the shoot length of the grass. The shoot (clippings) dry weights of the plants followed essentially the same pattern as the shoot lengths. The visual evaluation of the grass supported the measured parameters.
    • Aquatrols Surfactant Study on Turfgrass Nutrient Uptake

      Walworth, James; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
    • Effect of Planting Hole Size and Amendments on Growth and Establishment of Acacia farnesiana

      Schuch, Ursula K.; Kelly, Jack; Stryker, Frank; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      The objective of this project was to determine whether the size of planting holes and the addition of organic material in the backfill is beneficial for plant establishment and growth during the early years. Acacia farnesiana were transplanted from containers into a permanent landscape using four methods: large planting hole with or without amendments or a small planting hole with or without amendments. The study was repeated on two sites. Three years following transplanting, plant growth such as height and caliper were not affected by the planting hole size or amendments, but differed significantly between sites. Plants that received more irrigation and were planted in a less rocky soil had greater caliper and were taller than those supplied with less irrigation and planted on a more rocky soil. Visual observations one and three years after transplanting indicate that trees that were amended with compost in the backfill had the highest incidence of leaning trunks and sinking crowns (20% of trees in study or 37% of those receiving amendments) while of those trees that were not amended only one tree (3%) was leaning three years after transplanting. Hole size at transplanting had no significant effect on leaning or sinking three years after transplanting. These results confirm earlier research across the country that 33% to 50% organic amendment in backfill compared to native soil at transplanting is not beneficial for native trees, but increases the risk of leaning or sinking.
    • Forcing Containerized Roses in a Retractable Roof Greenhouse and Outdoors in a Semi-Arid Climate

      Schuch, Ursula K.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Sales of containerized roses have increased dramatically in recent years and producing flowering plants in containers in a timely manner is important to the nursery industry. An experiment was conducted to determine whether forcing containerized roses will be faster in a retractable roof greenhouse compared to outdoors. Results suggest that forcing roses in a retractable roof greenhouse can shorten the production time and increase quality of finished plants, however, cultivar, time of harvesting, and time in cold storage also affect these parameters.
    • Evaluation of Pyrus Interspecific Hybrids in Arizona from 2001 – 2004

      Schuch, Ursula K.; Call, Robert; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Pyrus calleryana are widely used in landscapes in regions where they are adapted, however there are many species of Pyrus that have not been explored for their potential use in landscapes, particularly in hot, arid climates. The Landscape Plant Development Center in Chanhassen, Minnesota has started a program to develop small statured pear trees for landscape use in different climates. This project in Arizona was initiated in conjunction with the Landscape Plant Development Center with the objective to test second generation hybrid Pyrus species for adaptation to the arid climate of the Southwest. Fifty trees were planted in Sierra Vista and 30 trees were planted in Tucson, Arizona, in March 2001. Plant growth, survival, and aesthetic characteristics were observed until fall 2004. Out of thirty trees tested at the Tucson site, one tree from the cross of Calleryana 'Chanticleer' x eleagrifolia appeared to be well adapted to the climate of the mid-elevation desert based on growth, branch structure and foliage health. Pyrus trees performed better in the cooler climate in Sierra Vista compared to Tucson. However, Texas root rot at the site decimated 40 of the 50 trees by the end of the fourth growing season. The aesthetically most pleasing tree at the Sierra Vista site was a cross between fauriei x betulifolia. This provenance was represented with 17 trees in Sierra Vista, nine of which showed good performance by October 2004. Trees from this provenance seem to be well adapted to the arid climate of the higher elevation desert and appear to have a number of desirable characteristics for urban landscapes.
    • 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.
    • Controlling Rhizoctonia Root Rot in Bedding Plants

      Mahato, Tilak; Olsen, Mary; Schuch, Ursula K.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Rhizoctonia root rot is caused by a soil borne fungus, Rhizoctonia solani and is a serious problem in bedding plants. The objective of this study was to determine the efficacy of three chemical and two biological products for controlling Rhizoctonia root rot in cool season and warm season bedding plants. Experiments were conducted with summer and winter bedding plants in a nursery production and landscape situation. The efficacy of conventional fungicides or biological products to control Rhizoctonia root rot in bedding plant production and simulated landscape growth cannot be evaluated from results of this study because of low mortality of plants.
    • Application of Proxy PGR for Poa Seed Head Suppression, 2000

      Kopec, David M.; Gilbert, Jeff J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Proxy (ethephon) was applied to 100% pure stands of Poa annua as either a single or repeat application 24 days apart at both a five and ten-ounce product rate per 1000 square feet. Percent plot seed heads were decreased significantly on three of five evaluation dates before either the loss of treatment effect and/or environmental conditions triggered profuse flowering (by 20 April, 2000). The five-ounce rate produced moderate seed head suppression at 16 and 25 days after the first treatments by which afterwards, control was minimal. By April, the five-ounce repeat applications were no better in suppression of seed heads than either of the single applications, regardless of application timing (March 3 or 29). The ten-ounce rates generally produced 40% - 80% greater seed heads suppression than the five-ounce rate treatments. Maximum seed head control was achieved by the repeat applications (March 3 and 29) of the ten-ounce rate, which consistently produced between 8% and 19%, seed head cover up until the first ten days of April 2000. Proxy, when applied at the five-ounce/M rate had the greatest effect in seed head suppression early in the test (10 March). Perhaps earlier season applications at the five-ounce rate may be necessary to manifest greater suppression initially, and perhaps in a cumulative fashion for season long control.
    • Late Season Application for Efficacy Screening of Select Herbicides for Post-Emergence Control of Khakiweed

      Kopec, David M.; Gilbert, Jeff; Pessarakli, Mohammed; Moreno, J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Khakiweed (Alternanthera pungens) was treated late in the season with select herbicides for initial screening of herbicides for post emergence control. Treatments were applied on October 7, 2004 and evaluated five weeks after treatment on Nov 16, 2004. The F ratio for the treatment main affect was highly significant for percent weed control. All rate affect contrasts were not significant for those treatments applied at two or more active ingredient levels. The "S.U. herbicides" vs. "all others" contrast was significant at P=0.05, as the S.U.. chemicals as a whole provided better coverage than the 2-4, D type and Penoxsulam. Percent weed control ranged from 7% to 99% late season control of Khakiweed. There were noticeable differences between S.U. products, as Revolver provided minimal weed control (7%) while Manor and Monument provided very good to excellent control (94% to 99%). Both Manor rates resulted in 99% control, while the three rates of Monument produced 94%-98% mean percent weed control values. Penoxsulam was intermediate, providing 56% and 70% control for the SC and G formulations, respectively. Banvel, 2-4, D and Buctril produced 22%-24% Khakiweed control. Tranxit had minimal affect (12%), as did Revolver at 6%.
    • 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.
    • ET Rates of Distichlis (Inland Saltgrass) Clones A119, A48,Sea Isle 1 Sea Shore Paspalum and Tifway Bermudagrass

      Kopec, David M.; Suarez, Armando; Pessarakli, Mohammed; Gilbert, Jeff J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      The ET rate of bermudagrass is relatively well known. The ET rate of Seashore paspalum in an arid environment is not, nor is there any information on the ET of Distichlis as a mowed turf. A greenhouse test using gravimetric lysimeters was conducted in the late summer of 2004 to measure and compare the ET of two Distichlis clones and Sea Isle 1 seashore paspalum to that of Tifway 419 bermudagrass. This test showed that under glass house conditions when soil moisture was not limiting: (1)Seashore paspalum had a higher ET rate than A119 saltgrass in terms of mm/day, and total consumptive water use for the 19 day test period, (2) A48 saltgrass and Tifway bermudagrass had similar daily ET rates and similar total water use, (3) total water use between two select saltgrass clones was not significantly different . Saltgrass A48 and A119 had a total consumptive water use of 84.2 and 76.5 mm, respectively over the 19 day test period. Tifway Bermuda totaled 82.2 mm, and Sea Isle 1 used 92.1 mm over 19 days.
    • 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 and Comparison of Spotlight* Herbicide Combinations for Khakiweed Control in Turf

      Umeda, Kai; Towers, Gabriel; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      The combination of Spotlight* at 1.0 pt/A plus Speedzone* at 4.0 pt/A gave 90% control of khakiweed at 14 days after treatment (DAT) and continued to offer acceptable control of 85% at 49 DAT. Acceptable control of 87 and 90% control was also observed at 14 DAT when Spotlight* was combined with Powerzone* or Speedzone*, respectively. The combinations of Spotlight* with Powerzone* or Trimec* were similar by marginally controlling khakiweed up to 21 DAT. Spotlight when combined with Turflon Ester* or Speedzone Southern* performed very similarly at all rating dates and did not offer acceptable khakiweed control.
    • Comparison of Sulfonylurea Herbicides for Spring Transition

      Umeda, Kai; Towers, Gabriel; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      In six field experiments that were conducted during the spring of 2004 with seven sulfonylurea herbicides for removing perennial ryegrass from bermudagrass turf, the most rapid response and effective ryegrass removal occurred with the latest applications made in June compared to applications made in April or May. Flazasulfuron, foramsulfuron, rimsulfuron, trifloxysulfuron, and chlorsulfuron were effective in removing most of the ryegrass. Sulfosulfuron and metsulfuron were least effective for removing ryegrass, especially during the cooler April and May timings.
    • 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.
    • Response and Nutrient Uptake in Bermudagrass Treated with Aquatrols Surfactant ACA 1848 in the Desert Southwest

      Walworth, James; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Aquatrols surfactant ACA 1848 was applied to Tifway 419 hybrid bermudagrass at rates of 12 or 48 ounces/acre and evaluated for turfgrass growth, performance, and nutrient uptake. Soil samples collected during the growing season were analyzed for inorganic nitrogen (ammonium and nitrate). Only on the last sampling date only (September 29), the soil nitrate-nitrogen level was slightly higher in the untreated control than in other plots. Otherwise, soil nitrogen levels did not differ among treatments. Growth measurements and visual ratings did not differ among treatments at any time during the growing season, indicating that surfactant treatments did not affect either of these parameters. Leaf clippings collected throughout the growing season were analyzed for total nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, sodium, boron, copper, iron, manganese, and zinc. With only one exception, differences in nutrient content among treatments were statistically non-significant at the 5% significance level. That exception occurred on August 18 when the turfgrass treated with surfactant at the 12 oz/a/wk level had less zinc than turfgrass in the 0 or 48 oz/a/wk treatments. There was a noticeable, but non-significant trend, observed as follows; the highest level of surfactant treatment (48 oz/a/wk) resulted in the highest tissue levels of phosphorus, potassium, sulfur, sodium, boron, and copper in samples collected on July 21 (day 203), August 4 (day 217), and September 1 (day 245). Calcium, magnesium, and iron levels were highest in this treatment on August 4, but these differences were extremely small and always statistically nonsignificant and this trend was not observed on other sampling dates. There were no consistent rate trend responses (i.e. where the higher level of surfactant treatment produced a greater response than the lower rate) throughout the test. On all sampling dates, the untreated control contained more manganese than either of the surfactant treatments; the differences were not statistically significant and were not rate related. In this field study, there were no turfgrass responses, either positive or negative, that we could attribute to Aquatrols ACC 1848 applied at 12 and 48 oz/a weekly. The magnitudes of response differences observed in this study were not large enough to identify statistically significant differences.
    • School IPM

      Gouge, Dawn H.; Smith, Kirk A.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
    • 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.