Turfgrass, Landscape and Urban IPM Research Report 2007-2008
ABOUT THE COLLECTION
The Urban IPM and Turfgrass Research Summary Report is one of several commodity-based agricultural research reports published by the University of Arizona.
This report was first published in 1988.
The purpose of the report is to provide an annual research update to turfgrass managers, landscape professionals and IPM practitioners. The research is conducted by University of Arizona faculty and staff.
Both historical and current issues have been made available via the UA Campus Repository, as part of a collaboration between the College of Agriculture and Life Sciences and the University Libraries.
David Kopec and Paul Baker are current co-editors of the Urban IPM and Turfgrass Summary. You can email them at firstname.lastname@example.org. You can also visit the CALS Publications website for additional information.
Contents for Turfgrass, Landscape and Urban IPM Research Report 2007-2008Urban Pest - IPM
- Using the Termiticide F4688 50 WP to Control Subterranean Termites around Structures in Southern Arizona
Diseases and Disease Control
- Evaluation of Fungicides for Control of Rapid Blight of Poa trivialis in fall 2006
- Detection of the rapid blight pathogen Labyrinthula terrestris on non-symptomatic Poa trivialis
- Comparison of Velocity* Rates with Multiple Applications for Poa annua Control in Turf
- Evaluation of Insecticides for Efficacy on Turfgrass Pests
- Evaluation of Herbicides for Khakiweed Control
- Timing of Sequential Applications for Nutsedge Control in Turfgrass
- Herbicides for Transition in Higher-Cut Rough Turf
- Fall Applications of Sulfonylurea Herbicides for Poa annua Control and Turfgrass Safety
- Growth Responses of Selected Warm-Season Turfgrasses under Salt Stress
- Comparing Growth Responses of Selected Cool-Season Turfgrasses under Salinity and Drought Stresses
Damage on Ornamental Landscape Plants Resulting from the January 2007 Freeze in ArizonaSevere freezing temperatures during January 2007 caused temporary and permanent damage in several species of ornamental landscape plants. The damage was exacerbated by three consecutive nights of frost and freezing temperatures lasting between 7and 14 hours each day. Observations of frost damage and recovery in Phoenix and Tucson were recorded.
Accumulation of Soil Salinity in Landscapes Irrigated with Reclaimed WaterThe long-term use of reclaimed water for landscape maintenance and the effects on soil chemistry and soil structure were investigated. Irrigation with reclaimed versus potable water for five years or more affects chemical properties of soil. Soils irrigated with reclaimed versus potable water had higher EC. Monsoon precipitation had less of a leaching effect than anticipated and significantly reduced EC only on two out of 13 sites. Soils irrigated with reclaimed water had higher SAR values than those irrigated with potable water and can potentially develop infiltration problems in the future. Contour maps of the EC for three depths of one site as measured by soil samples and EC as predicted by EM38 measurements for pre- and post-monsoon sampling times were developed.
Salinity Tolerance of Cacti and SucculentsThe salinity tolerance of golden barrel cactus (Echinocactus grusonii), ocotillo (Fouquieria splendens), saguaro cactus (Carnegiea gigantea), and Gentry’s agave (Agave parryi truncata) was tested. Plants were irrigated with a solution of EC 0.6, 5.0, 10.0, and 15.0 dS/m. Duration of treatments were 18 weeks for saguaro and 26 weeks for the other three species. In general, fresh weight, dry weight, and moisture content decreased with increasing salinity levels, with the exception of saguaro dry weight which was not affected by the treatments, and ocotillo moisture content which increased with increasing salinity. Runoff was collected three times during the experiment and indicated that ion uptake was higher for barrel cactus than the other three species. EC of runoff averaged for all dates and species showed an increase of 17%, 54%, 46%, and 64% over the salinity treatment solutions of 0.6, 5.0, 10.0, and 15.0 dS/m, respectively.
Comparing Growth Responses of Selected Cool-Season Turfgrasses under Salinity and Drought StressesThis study was conducted in a greenhouse, using hydroponics system, to compare growth responses of three cool-season turfgrass species, Creeping bentgrass (Agrostis stolonifera), Rough bluegrass (Poa trivialis), and Perennial ryegrass (Lolium sperenne) in terms of shoot and root lengths and dry matter (DM), and percent canopy green cover (%CGC) under salinity and drought stresses. Grasses were grown in Hoagland solution for 90 days prior to initiation of salinity or drought stresses. Then, 24 meq NaCl/L culture solution/day were added for each -0.1 MPa OP of salinity stress, or 75 and 119 g of PEG/L were added for -0.2 and -0.4 MPa OP of drought stress treatments, respectively. The treatments included control, -0.2 and -0.4 MPa OP salinity, -0.2 and -0.4 MPa OP drought stress. Four replications of each treatment were used in a RCB design experiment. During the stress period, grass shoots were clipped weekly for DM production, shoot and root lengths were measured, and %CGC was evaluated. The weekly clippings and the roots at the last harvest were oven dried at 60o C and DM weights were recorded. All 3 grass species were more severely affected by drought than salinity. Bluegrass was the most and bentgrass the least severely affected by either drought or salinity stress.
Growth Responses of Selected Warm-Season Turfgrasses under Salt StressUse of low quality/saline water for turf irrigation, especially in regions experiencing water shortage is increasing. This imposes more salt stress on turfgrasses which are already under stress in these regions. Therefore, there is a great need for salt tolerant turfgrasses to survive under such stressful conditions. This study was conducted in a greenhouse, using hydroponics system, to compare growth responses of three warm-season turfgrasses, bermudagrass (Cynodon dactylon L.), cv. Tifway 419, seashore paspalum (Paspalum vaginatum Swartz), cv. Sea Isle 2000, and saltgrass (Distichlis spicata L), accession A55 in terms of shoot and root lengths and DM, and canopy green color (CGC) under salt stress condition. Whole plants, stolons, and rhizomes were grown in Hoagland solution for 4 months prior to initiation of salt stress. Then, plants were grown for 12 weeks under 4 treatments (control, 7000, 14000, and 21000 mg/L NaCl) with 4 replications in a RCB design trial. During the stress period, shoots were clipped bi-weekly for DM production, shoot and root lengths were measured, and CGC was evaluated weekly. The bi-weekly clippings and the roots at the last harvest were oven dried at 60o C and DM weights were recorded. Shoot and root lengths and shoot DM weights decreased linearly with increased salinity for bermudagrass and paspalum. However, for saltgrass these values increased at all NaCl levels compared with the control. For bermudagrass and paspalum, the highest values were obtained when the whole plants were used, and the lowest ones resulted when the rhizomes were used. The reverse was found for saltgrass. For the control plants, the measured factors were higher and the canopy colors were greener for bermudagrass and paspalum compared with saltgrass. The canopy color changed to lighter green for bermudagrass and paspalum as NaCl salinity increased, but saltgrass maintained the same color regardless of the level of salinity.
Fall Applications of Sulfonylurea Herbicides for Poa annua Control and Turfgrass SafetyCertainty, Monument, and TranXit gave variable Poa control in the spring at 6 to 8 months after applications that were made prior to fall overseeding. There was not consistent Poa control with respect to timing of applications from one month to two weeks before overseeding. Most Poa control in February or April was marginally acceptable at 85% control or less. Common bermudagrass treated with the sulfonylurea herbicides was affected with observable reduced quality. The ryegrass density at 10 days after first water appeared to be less for all treatments compared to the untreated check. At one month after overseeding, all plots had ryegrass well-established and quality ratings were comparable to the untreated check for all treatments.
Herbicides for Transition in Higher-Cut Rough TurfThe herbicides foramsulfuron, trifloxysulfuron, and sulfosulfuron applied in late April followed by a sequential application 2 weeks later in early May were more effective for removing ryegrass than when the sequential application was made 7 weeks later in June. Rimsulfuron at 0.013 lb a.i./A and flazasulfuron at 0.0078 lb a.i./A were highly effective in rapidly removing ryegrass with a single application. Minimal activity was observed for the herbicides at 7 or 9 days after application in April and early May. Ryegrass removal was enhanced when applications were made during warmer temperatures in late May and into June. Rate ranges of sulfosulfuron and flazasulfuron indicated a trend that higher rates may be slightly more effective than lower rates but ryegrass removal was achieved with all rates.
Timing of Sequential Applications for Nutsedge Control in TurfgrassSequential applications of all of the ALS-inhibiting herbicides offered acceptable to excellent levels of nutsedge control in turf. Single applications generally provided nutsedge control for 2 to 6 weeks. Single applications of halosulfuron and flazasulfuron offered effective control for 2 weeks and less than 4 weeks. Effective nutsedge control by trifloxysulfuron and sulfosulfuron was observed at 31 days after treatment (DAT) and began to decline at 42 DAT. Sulfosulfuron at 0.094 lb a.i./A applied sequentially at either 4 or 6 weeks gave near complete nutsedge control at the end of the season at the end of September. A second application of trifloxysulfuron at 0.026 lb a.i./A at 4 or 6 weeks after a first application in mid-July resulted in controlling nutsedge better than 85% at the end of September. Flazasulfuron at 0.047 lb a.i./A applied sequentially at 6 weeks provided improving nutsedge control through the summer and resulted in near complete control at 95% at the end of September. Halosulfuron at 0.062 lb a.i./A showed only 65% control after the first application and a sequential application at 4 weeks improved control to 92% for only an additional 2 weeks and then control was less than acceptable at the end of the season. Imazaquin at 0.5 lb a.i./A gave less than acceptable but consistent control until sequential applications at both 4 and 6 weeks improved nutsedge control to acceptable levels.
Evaluation of Herbicides for Khakiweed ControlSpeedzone at 4.0 pt/A provided rapid control of khakiweed and gave 82% control at 17 days after treatment in one of three experiments. Spotlight at 1.0 pt/A alone was only effective at about 50%. BAS-514 and BAS-790 were not effective against khakiweed when applied alone. In a second experiment, sequential applications of Speedzone and Spotlight plus Turflon Ester provided exceptional control of greater than 95%. Initial applications of the POST applications that were combined with Gallery offered control of new emerging seedlings of khakiweed. Monument combined with Gallery gave decreased khakiweed control compared to Monument applied alone. An antagonistic effect could be occurring with the tank-mix combination of the two herbicides. Carfentrazone containing products, QuickSilver at 2 oz/A alone was not effective on khakiweed compared to the package mix product Speedzone. For the ALS-inhibiting herbicides, flazasulfuron and Certainty were the least effective while penoxsulam and Image were comparable to Monument in providing about 50% control.
Evaluation of Insecticides for Efficacy on Turfgrass PestsNo masked chafer larvae were observed for treatments of imidacloprid, imidacloprid plus bifenthrin, clothianidin, and the two higher rates of DPX-E2Y45. The inconsistent and low populations of masked chafer larvae and billbugs in the turfgrass did not provide for conclusive results. Clothianidin and the two higher rates of DPX-E2Y45 had no billbug larvae. An early rating date showed that more billbug adults were in turf treated with imidacloprid and DPX-E2Y45. Later rating dates showed a decline in adults for all treatments.
Comparison of Velocity* Rates with Multiple Applications for Poa annua Control in TurfVelocity at 40 gm a.i./A was more active than 20 gm a.i./A which was more active than 10 gm a.i./A. Velocity at 40 gm a.i./A consistently gave better than 74% Poa control but less than commercially acceptable levels. Velocity at 20 gm a.i./A gave between 50 to less than 70% control. Velocity at 10 gm a.i./A was marginally active against Poa giving less than 60% control.
Detection of the rapid blight pathogen Labyrinthula terrestris on non-symptomatic Poa trivialisRapid blight is a new disease of cool season turf grasses caused by Labyrinthula terrestris. It is problematic in Arizona and ten other states in cool season turfgrasses at sites with elevated salinity of soil and/or irrigation water. L. terrestris colonizes Tifgreen bermudagrasses in the field, but causes no apparent disease. Laboratory trials have shown that as concentrations of sodium chloride in irrigation water increase, disease severity increases, and when calcium and potassium salts are used to increase salinity, disease is greatly reduced or not observed. In preliminary field assays of cool-season turfgrasses irrigated with effluent, L. terrestris was observed in laboratory cultures from non-symptomatic turfgrass. To further substantiate if L. terrestris and/or other Labyrinthula species were present in non-symptomatic turfgrass in the field and to determine if disease could be induced by increased salinity, a trial was conducted at the Karsten Turfgrass Research Facility of The University of Arizona. In August 2006, field plots were established in bermudagrass "Tifway 419" and overseeded with Poa trivialis "Laser" in October. Plots were treated with potassium chloride, potassium sulfate or sodium chloride salts to increase soil salinity. Other plots treated with fungicides that are ineffective in controlling rapid blight as well as a sulfur treatment also were included in the assays. Poa trivialis was sampled in December 2006 and April 200. In laboratory assays using a semi-selective medium, Labyrinthula was detected in all treatments. Incidence was significantly higher in the untreated control and fungicide treated plots than in the salt treated plots. Results show that increasing soil salinity did not induce disease or result in an increase in detection of Labyrinthula at this site. Results of this study on Poa trivialis and previous studies on Tifgreen bermudagrass suggest that Labyrinthula may be widespread in non-symptomatic turfgrasses.
Evaluation of Fungicides for Control of Rapid Blight of Poa trivialis in fall 2006Rapid blight is a new disease of cool season turf grasses caused by Labyrinthula terrestris, an organism in a group referred to as the marine slime molds. A trial was conducted in fall 2006-winter 2007 to repeat an evaluation of efficacy of different rates and intervals of Insignia fungicide and elemental sulfur, both of which gave acceptable control in trials in 2005. The trial was conducted at a golf course in central Arizona with a previous history of disease and high salinity irrigation water (about 5 dS/m). Plots were established in August 2006 on a practice tee on which Champion 419 bermudagrass was overseeded with Poa trivialis "Laser". Treatments included pyraclostrobin (Insignia) as a preventive and as a curative, pyraclostrobin (Insignia) combined with Fore as a preventive, and elemental sulfur (DsiperSul) as a preventive. Disease symptoms appeared immediately after the first mowing. Disease ratings 15 days after first mow showed that applications of the high rate of Insignia at first mow gave excellent control. Moderate control was shown in applications with early applications of Fore combined with the lower rate of Insignia. Treatments with Insignia as a curative and with sulfur as a preventive were not acceptable.
Using the Termiticide F4688 50 WP to Control Subterranean Termites around Structures in Southern ArizonaThe critical features needed for long-standing structural protection against subterranean termites are chemical efficacy and stability of termiticides. Federal regulations concerning minimum product performance of termiticide treatments stress the importance of field-testing existing and candidate termiticides. Field tests are designed to simulate typical application conditions and provide the regulated community non-penetration data. The purpose of this study was to evaluate the termiticide Transport® in terms of providing structural protection and consumer satisfaction against Heterotermes aureus. Five residential structures were selected in Tucson for the study. None of the homes had undergone any treatment for termites within 12 months and all were of one construction type, frame stucco with slab foundations. The effectiveness of the termiticide Transport® in controlling Heterotermes aureus based on the five homes was very good. Termites were cleared in under a month when inspections were performed. Standard difficulties were encounter in gaining access to structures for inspections. Coordination with homeowners varied greatly and required persistence by the inspectors.