• 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.
    • Overseed Performance of Sea Isle 2000 Seashore Paspalum

      Kopec, David M.; Gilbert, Jeff J.; Pessarakli, Mohammed; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      The new Seashore paspalum 'Sea Isle 2000' is being used as a greens surface in many tropical - semi tropical climates were saline water is available for irrigation. While it’s color retention in the fall in Tucson Arizona is good, it still enters full winter dormancy, and requires overseeding with a cool season grass for late fall, winter, and spring play. A two year test was conducted to evaluate the tolerance of Sea Isle 2000 to overseeding, and to evaluate overall turf performance of perennial ryegrass (PR), Poa trivialis (PT) and a mixture of the two when used for overseeding over Sea Isle 2000. PT alone was slow to establish as an overseed in year one, but not in year two. Turfgrass color, quality density and texture were acceptable throughout the test, noting that the 100% perennial ryegrass plot demonstrated a short-term loss of performance during the cold January of 2004. After the initial grow in period, absolute BRD was greatest when growing conditions were less than optimum in mid-winter, and again at the seasons end at the beginning of spring transition (May). This was true in both years. BRD was generally not different between the three overseeding regimes, either when turfs were double mowed prior to BRD measurements, or when a single rolling event was added on the day that BRD was assessed. The 100% PR overseed treatment showed the largest numerical increases in BRD from rolling. This was 6.5 inches in year one and 9.2 inches in year two. Yearly BRD averages of all overseeded surfaces for turfs that were double mowed in year one ranged from 91.5 to 92.4 inches, and in year two from 92.2 to 93.3 inches. Average yearly BRD values among all overseed turfs when rolling was included (including double mowing) in year one ranged from 95.8 to 98.2 inches and from 99.2 to 100.5 inches in year two. Maximum BRD values obtained were 107.8 and 114.3 inches in year one, and 100.0 and 111.1 inches in year two for the mowed only turfs, and mowed and rolled turfs, respectively.
    • Evaluation of Fungicides for Control of Rapid Blight of Poa trivialis (2003)

      Olsen, Mary W.; Gilbert, Jeff J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Rapid blight is a new disease of cool season turf grasses that has occurred on over a dozen golf courses in Arizona. It is now known to be caused by Labyrinthula terrestris, an organism in a group referred to as the marine slime molds. A trial was conducted in fall 2003 and winter 2004 to evaluate efficacy of selected fungicides for control of rapid blight at a golf course in central Arizona with a previous history of disease. Plots were established in late October2003 on a practice green on which Bermuda was overseeded with Poa trivialis. Treatments included Compass, Insignia, Fore, Bordeaux, Kocide 2000, Microthiol Disperss, Ecoguard and Floradox in various combinations and application dates. Disease symptoms appeared about 6 weeks after the first mowing and were evaluated in mid January. Results indicate that applications of Fore, Insignia and tank mixes of Insignia and Compass with Fore gave excellent control. Bordeaux, Compass alone, Compass alternated with Fore, Insignia alone, and Kocide gave good control. Microthiol Disperss, Floradox and Ecoguard gave poor control.
    • 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.
    • 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.
    • Growth Responses of Bermudagrass to Different Levels of Nutrients in the Culture Medium

      Pessarakli, Mohammed; Kopec, David M.; Gilbert, Jeff J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Bermudagrass (Cynodon dactylon L.), cv. Arizona Common was studied in a greenhouse to evaluate its growth responses in terms of shoot and root lengths and shoot and root dry weights under different levels of nutrients. Plants were grown hydroponically under five levels of nutrients in the growth medium [Full Nutrients (FN), Half Nutrients (½N), Quarter Nutrients (1/4N), One Eighth Nutrients (1/8N), and One Sixteenth Nutrient (1/16N)], using Hoagland solution No. 1. 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 shoot length, shoot and root dry weights, shoot total-N contents and concentrations, and the % of canopy green cover significantly decreased at lower (1/8 & 1/16) nutrient levels. This reduction was more pronounced as growth period progressed. Root length was stimulated at lower (1/4, 1/8, and 1/16) nutrient levels of the culture solutions. The differences in shoot lengths and shoot and root dry weights were not significant among the Full, 1/2, and 1/4 nutrient levels of the culture solutions. The differences in shoot total-N content and concentrations were not significant among the Full, 1/2, and 1/4 nutrient levels. There was no difference in either shoot total-N contents or concentrations among the respective nutrient treatments at different harvests. The above results were observed for both cumulative as well as the weekly growth responses.
    • AEF 130360 Overseeding Safety

      Kopec, David M.; Gilbert, Jeff J.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Several items need consideration when products are evaluated for use as transition agents. These are (1) efficacy of ryegrass removal [rate of ryegrass decline and appearance of turf during transition], (2) tolerance and performance of incoming bermudagrass and (3) application safety for next season’s repeat overseed operations. This test was designed to evaluate application safety for the next overseeding which occurs in the early fall. Therefore, AEF was applied in the summer to bermudagrass turf prior to overseed operations. Most responses of the perennial ryegrass (overseed) turf to previous treatments of AEF 130360 occurred immediately after overseeding, from mid-October to early November. AEF 130360 applied 2 weeks before overseeding caused a significant decrease in seedling vigor, percent plot ryegrass cover, and percent bermudagrass plot straw present. Both AEF treatments applied closest to overseeding (2 weeks prior) had the least amount of initial ryegrass, the greatest amount of green bermudagrass, and later in the season, the most amount of straw (dormant) bermudagrass. Differences in turfgrass quality were not significant due to treatments at any time throughout the test, and most treatments ranked higher than the control in overall quality. Under the conditions of this test, application of AEF 130360 at either 0.64 or 1.28 ounces/product/M made one month before actual oversseding did not cause detrimental effects to ryegrass emergence, ryegrass cover, turfgrass color or overall quality.
    • 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.
    • Response of Nitrate and Ammonium on Growth of Prosopis Velutina and Simmondsia Chinensis Seedlings

      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 whether mesquite (Prosopis velutina) and jojoba (Simmondsia chinensis) seedlings have a preference for the ammonia or nitrate form of nitrogen (N) to maximize growth and minimize N leaching when seedlings were grown in sand culture. Seedlings were fertigated with different ratios of NH₄⁺:NO₃⁻ to determine effects on shoot and root growth and N leaching. Nutrient solution containing 67 % NH₄⁺: 33 % NO₃⁻ resulted in greatest biomass of mesquite seedlings after 120 days of fertigation. N tissue concentrations of mesquite seedlings were highest for plants supplied with 100% ammonium. N leachate remained stable until 12 weeks after the onset of treatment, but increased significantly by week 16. Dry weight of jojoba seedlings did not differ throughout the experiment regardless of the nutrient solution provided, however N tissue concentration in jojoba seedlings fertigated with 100% ammonium was twice as high as that of plants fertigated with 100% nitrate.
    • Use of Foramsufulron (TADS) as a Transition Agent to Remove Poa Trivialis from an Overseeded Tifgreen Bermudagrass Putting Green

      Kopec, David M.; Gilbert, Jeff J.; Pessarkli, Mohammed; Umeda, Kai; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Five sulfonylurea urea herbicides and one PGR were applied to a Tifgreen bermudagrass putting green to determine their response as spring applied transition aids to enhance the removal of Poa trivialis ovrseed. All sufonyl urea herbicide caused marginal to extreme injury to Poa trivialis by 9 DAT, which lasted at least a minimum of 3 weeks. Manor caused the least amount of injury and discoloration, but had little effect in promoting the transition back to bermudagrass. Tranxit caused extreme plot injury (leaf bronzing), but forced transition. The injury resulted in unacceptable quality. Embark PGR enhanced transition at 9 DAT only, with acceptable quality. After a second application of Emark, quality was reduced to sub-marginal levels, which was caused by straw colored leaf sheaths. TADS increased Bermuda transition at 9 DAT, but not at 23 DAT, regardless of the addition of fungicides, or not. The addition of fungicides to TADS in general did not affect color, quality or turf transition, with the exception on Jens 7 (38 DAT) when the lower rate (0.10 ounce/p/M) with fungicide had excellent quality (6.8) due to readily observed visual density (7.5). Trifloxysulfuron caused increased transition at 9 DAT only, and developed moderate turf injury, as well as poor turf color at 9 and 23 DAT. All entries produce turfs with good color, quality and density by 31 July. After a standard aerification and topdressing, and fertilization with 1.5 lbs of additional -N- / M. No treatments produced enhanced transition without marginal to unacceptable turf performance. TADS at 0.10 ounce/p/M were safer to the turf than was the 0.20 ounce/p/M rate of TADS.
    • Response of Cool Season Turfs when Overseeded on a Putting Green with a History of Rapid Blight Disease

      Kopec, David M.; Olsen, Mary W.; Gilbert, Jeff J.; Bigelow, Donna M.; Kohout, Michele; Twito, Mick; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Rapid blight disease is a potentially devastating disease on cool season overseed turfs when irrigated with saline water. A two year test was conducted on a closely mowed Tifgreen bermudagrass turf which was infected with visual symptoms of necrotic patches of turf, and various degrees of blighting. The test included a broad representation of turf species for overseeding in an effort to (1) determine selected specie/cultivar susceptibility and disease expression to rapid blight in the field and (2) survey and assess the association of laboratory isolate detection from field sampling, with disease occurrence and severity of expression of field maintained overseed turf. Over a two year period, Rapid blight, caused by Labyrinthula terrestris was capable of infesting most cool season grasses in this test. In year one, Dawson CRF, SRX 555 slender creeping red fescue, and SR 105210 slender creeping red fescue showed no positive lab detection results from field plots. In year two (2003-2004), only SRX 555 SLQ had only 1 plot known to carry Labyrinthula throughout the main infestation season. In year two, essentially all turf plots showed some symptomology of disease expression. This was confirmed by lab identification. Tiller infection rates varied from 2% to 80% infection in the lab from field samples. The relationship between tiller infection rates and field plot disease expression was determined by Pearson’s product and Spearman Rank correlation coefficients. Field plot disease scores were correlated with percent tiller infection rates, R² = -0.56 plot basis, and R² = –0.71 treatment mean basis, respectively. Spearman Rank correlation coefficients were R² =; -0.62 on a plot basis, and R² =–0.78 based on treatment means Agreement between the disease condition (yes/no) vs. lab findings (positive/negative) occurred on 51 of 59 plot cases, and was significant compared to chance alone occurrences. Over two years, entries which had low disease scores included Fult’s alkali grass, Dawson creeping red fescue, SRX 555 SLQ slender creeping red fescue, SR 5210 slender creeping red fescue, and Providence creeping bentgrass. Over two years, entries which produced high field disease rating scores included SR 3100 Hard fescue, TransEze intermediate ryegrass, SR 4400 perennial ryegrass, SR 7200 velvet bentgrass, SR 7100 colonial bentgrass, Sabre and Laser Poa trivialis, and Redtop.
    • Can Applied ABA be Used in Desert Turfgrass Management?

      Kopec, David M.; Suarez, Armando; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
    • TADS 14776, Manor, Kerb and Corsair Herbicides for Use as Spring Transition Aids in Overseeded Common Bermudagrass Turf

      Kopec, David M.; Gilbert, Jeff J.; Pessarakli, Mohammed; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Spring transition of overseeded turf has become a major challenge to turfgrass managers in the southern United States. Turf-type ryegrasses which exhibit increased mowing and heat tolerance have made the return of bermudagrass problematic, especially in common bermudagrass. Herbicides were evaluated for use as a Spring transition agent to decrease ryegrass competition/enhance bermudagrass. Treatments of TADS 14776 experimental herbicide, Manor, Kerb and Corsair were applied to overseeded common bermudagrass on may 6, 2001. Application of TADS experimental herbicide at all rates above 0.21 ounce/product increased bermuda enhancement over Kerb, Corsair and Manor, by 29 June 2001. When applied with extra fertilizer applications, the 0.21 ounce rate of TADS was greater than that of Kerb, Corsair and Manor for bermuda transition. TADS applied at the highest rate of 0.64 ounce (+) fertilizer, and TADS @ 0.42 ounce (+) GENAPOL 150 surfactant and extra plot fertilizer, were the first treatments to exhibit total necrosis of the perennial ryegrass overseed by 4 June (1 month after treatment). However, these treatments created a poorer quality turf, compared to other treatments. TADS @ 0.42 ounce (+) extra plot fertilizer ranked highest in bermudagrass plot cover, with five times as much bermudagrass present than untreated controls on 29 May. This same treatment continued with this trend, achieving 100% bermudagrass cover by 29 June (highly desirable). This treatment resulted in a brief decrease in turfgrass quality at 9 and 16 days after treatment (14 May, 21 May). With that in mind, TADS @ 0.42 ounce (+) extra plot nitrogen proved to be the best treatment that produced acceptable levels of turf quality throughout the transition, yielding the fastest re-establishment of the underlying common bermudagrass. At the close of the test on 10 July, TADS @ 0.21 ounce (+) fertilizer and TADS @ 0.42 ounce (+) fertilizer closed with 88% and 99% bermudagrass cover, and mean quality scores of 6.0 and 7.0 respectively. At the close of the test, untreated overseeded common bermudagrass yielded unacceptable turf quality, 19% bermudagrass cover, 14% living green ryegrass cover, with the remainder being dead ryegrass (straw).
    • Efficacy of Herbicides for Nutsedge Control in Turf

      Umeda, Kai; Towers, Gabriel; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      The efficacy of six ALS herbicides for controlling purple nutsedge in bermudagrass turf was demonstrated in five field experiments during the summer of 2004. The highest degree of nutsedge control at 95% at the end of the summer was observed after three monthly applications of trifloxysulfuron at 0.026 lb a.i./A.. Three monthly applications of halosulfuron at 0.062 lb a.i./A controlled nutsedge 88 to 90% at the end of September to early October. Imazaquin at 0.5 lb a.i./A plus MSMA at 3.0 lb a.i./A gave 91% control of nutsedge with three applications. The most rapid and efficacious nutsedge control was observed with flazasulfuron giving 91% control at 15 days after a single application. The highest degree of nutsedge control with a single application of sulfosulfuron was 91 to 96% control at 28 days after treatment. In general, ALS herbicides applied as a single application or multiple applications provided one month of effective control following a first application. After one month, the degree of control declined unless repeated applications at monthly intervals or as needed were applied for extended control. Penoxsulam at 0.12 lb a.i./A in one test gave only 70% control. MSMA at 3.0 lb a.i./A was applied four times and nutsedge control at the end of the season was 63 to 66%.
    • Response of Sea Isle 2000 Paspalum to Mowing Height and Nitrogen Fertility as a Putting Surface Under Semi-Arid Conditions; Two Year Report

      Kopec, David M.; Walworth, James H.; Gilbert, Jeffrey J.; Sower, Greg M.; Pessarakli, Mohammed; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
    • Response of Sea Isle I Paspalum to Fertilization and Mowing for Tee and Fairway Turf

      Kopec, David M.; Walworth, James H.; Gilbert, Jeffrey J.; Sower, Greg M.; Pessarakli, Mohammed .; Kerr, D.; Spense, J; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
    • Infection of Selected Turfgrasses by Labyrinthula terrestris

      Bigelow, Donna M.; Olsen, Mary W.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      A number of turfgrasses were screened in the greenhouse and laboratory for susceptibility to Labyrinthula terrestris, a new turfgrass pathogen that causes rapid blight of cool season turfgrasses. Salt tolerant varieties and warm season grasses such as Bermuda grass, tufted hairgrass, inland saltgrass, centipede grass, seashore paspalum and kikuyugrass were not susceptible; cool season grasses such as velvet bentgrass, annual ryegrass, perennial ryegrass, annual bluegrass, Kentucky bluegrass, and rough bluegrass were very susceptible.
    • The Effect of Sulfonylurea (SU) Herbicides on Establishment of Seeded Bermudagrass when Applied to Remove Perennial Ryegrass Turf

      Murphree, Trent; Rodgers, Charlie; Towers, Gabriel; Umeda, Kai; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004-02)
      Higher SU herbicide rates provided more effective ryegrass removal that resulted in improved establishment of the seeded bermudagrass. In most instances in this study, the percent bermudagrass coverage increased as herbicide rates increased. Glyphosate was very effective in completely removing ryegrass non-selectively. Flazasulfuron at 0.018 lb ai/A eliminated 88% of the ryegrass. Observations also showed that foramsulfuron, rimsulfuron,and chlorsulfuron were effective in removing ryegrass. In plots where ryegrass had been eliminated, faster bermudagrass coverage in a greater area of the plot was achieved. The least amount of bermudagrass coverage occurred in the untreated plots. It appeared that most of the herbicides evaluated in this study were relatively safe on seeded Princess 77 bermudagrass since emergence and establishment occurred in all plots. The speed and degree of coverage in the plots increased due to efficacy of the herbicides in eliminating ryegrass prior to seeding.
    • 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.
    • 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)