Turfgrass, Landscape and Urban IPM Research Report 2006
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 2006Urban IPM
- Survivability of the Subterranean Termite Heterotermes aureus When Exposed to Different Temperatures and Relative Humidity
- A Comparison of the Firstline and Sentricon Termite Colony Elimination Systems Efficacy on Heterotermes aureus in Southern Arizona
Diseases and Disease Control
- Evaluation of Fungicides for Control of Rapid Blight of Poa trivialis in Fall 2005
- Isolation of the Rapid Blight Pathogen Labyrinthula terrestris from Bermudagrasses in Arizona
- Comparison of Spring and Summer Herbicide Applications for Nutsedge Control in Turfgrass
- Postemergence Herbicides for Broadleaved Weed Control in Dormant Bermudagrass Control
- Comparison of Sulfonylurea Herbicides in Turf for Spring Transition
- Evaluation of Rates of Herbicides for Nutsedge Control
- Velocity Herbicide for Poa annua Control in Winter Turf
Velocity Herbicide for Poa annua Control in Winter TurfSequential applications of 45 gm AI/A tended to show more Poa annua suppression than 30 + 30 gm AI/A or 60 + 30 gm AI/A. Velocity applied twice at a 1 week interval showed slightly greater Poa annua suppression than when applications were made 2 or 3 weeks apart. Poa annua control was marginally acceptable at one of two sites when sequential applications were made at a 1 week interval.
Evaluation of Rates of Herbicides for Nutsedge ControlSulfosulfuron showed the highest degree of nutsedge control after the first application among all of the treatments at 4 WAT. Nutsedge control began to decline at 6 WAT after a single application of sulfosulfuron. Halosulfuron, trifloxysulfuron, and penoxulam showed very good nutsedge control at 2 WAT after a second application was made. Trifloxysulfuron at 0.026 lb AI/A and penoxulam at 0.125 lb AI/A performed very similarly to halosulfuron at 0.047 and 0.062 lb AI/A. Halosulfuron and flazasulfuron were more effective at higher rates of application when a series of rates were compared. Halosulfuron at 0.047 and 0.062 lb AI/A were very similar at most rating dates and both rates gave acceptable nutsedge control of 86 to 88% control at the end of the season. The two highest rates of flazasulfuron at 0.023 and 0.047 lb AI/A gave almost acceptable control. Sulfentrazone was not effective in providing acceptable nutsedge control at the rate tested.
Comparison of Sulfonylurea Herbicides in Turf for Spring TransitionFlazasulfuron and rimsulfuron were the most active in removing ryegrass within two weeks of application. Chlorsulfuron and the higher rates of foramsulfuron and trifloxysulfuron were moderately active in removing ryegrass. Sulfosulfuron, metsulfuron, and the lower rate of foramsulfuron were least active. All treatments including the untreated check had transitioned nearly completely in six weeks. Flazasulfuron, rimsulfuron, metsulfuron, chlorsulfuron, and sulfosulfuron treatments did not vary significantly between low and high rates that were tested. The higher rates of foramsulfuron and trifloxysulfuron were significantly more effective than the low rates that were tested. Flazasulfuron was the most injurious and delayed bermudagrass transition.
Postemergence Herbicides for Broadleaved Weed Control in Dormant Bermudagrass ControlThe treatments that included 2,4-D, mecoprop, and dicamba effectively controlled burclover and malva in the dormant bermudagrass turf. The addition of carfentrazone to the hormonal herbicides (Speedzone*) appeared to enhance malva control earlier than the other treatments. Surge* containing sulfentrazone with hormonal herbicides gave the highest degree of malva control. Fluroxypyr (Spotlight*) was not effective against burclover and showed moderate control of malva in this test.
Comparison of Spring and Summer Herbicide Applications for Nutsedge Control in TurfgrassSulfosulfuron, imazaquin, and halosulfuron applied beginning in May exhibited a high degree of nutsedge control from August to the end of September. Late spring initiated applications of imazaquin, sulfosulfuron, and trifloxysulfuron gave consistent nutsedge control that was better than 85% for most of the rating dates through the summer. Halosulfuron and flazasulfuron tended to decline in nutsedge control efficacy about one month after applications. The summer timing series of three monthly applications that began in July showed that sulfosulfuron and trifloxysulfuron provided an average of better than 90% nutsedge control throughout the summer. Applications of all herbicides in May caused ryegrass injury. Halosulfuron applications initiated in May were marginally safer on overseeded ryegrass while providing a moderate degree of nutsedge control. Bermudagrass was very slow to recover and to achieve full cover in sulfosulfuron and imazaquin treated plots.
Isolation of the Rapid Blight Pathogen Labyrinthula terrestris from Bermudagrasses in ArizonaRapid blight is a new disease of cool season turfgrasses that affects several important turfgrasses used for overseeding Bermuda in Arizona such as Poa trivialis and Lolium perenne (perennial rye). It is caused by Labyrinthula terrestris, an unusual organism that causes collapse of susceptible hosts and usually occurs in turfgrasses irrigated with moderate to high salinity irrigation water (EC>2.0). Rapid blight has not been observed in the field in warm season grasses such as Cynodon sp. (Bermudagrass) although laboratory trials have shown that common Bermudagrass and other grasses may be hosts. Because the survival mechanism of Labyrinthula terrestris in the absence of cool season turfgrass hosts was unknown, this study was initiated to determine if L. terrestris "over-summers" in different Bermudagrass systems. Results of assays of several different Bermudagrass systems show that Bermudagrasses are good hosts for L. terrestris and explains why rapid blight is a perpetual threat year after year in the same locations.
Evaluation of Fungicides for Control of Rapid Blight of Poa trivialis in Fall 2005Rapid blight is a new disease of cool season turf grasses that has occurred on over a dozen golf courses in Arizona. It is caused by Labyrinthula terrestris, an organism in a group referred to as the marine slime molds. A trial was conducted in fall 2005-winter 2006 to evaluate efficacy of selected fungicides for control of rapid blight 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 late October 2005 on a practice tee on which Bermuda was overseeded with Poa trivialis. Treatments included Insignia and Fore, alone and in combinations; elemental sulfur, potassium sulfate and potassium chloride as pre-plant applications on Bermuda; gypsum, Daconil Zn, Heritage TL, Soil Life and Soil Builder. Disease symptoms appeared immediately after the first mowing. Disease ratings at 3 weeks after first mow showed that applications of the high rate of Insignia at first mow and the pre-overseed application of sulfur gave excellent control. Moderate control was shown in applications with early applications of Fore alternated with the lower rate of Insignia, Fore alone, Soil Life, and of the high rate of Insignia combined with Fore applied as a curative at first disease. Treatments with Daconil Zn, Heritage TL, Soil Builder, and preoverseed treatments with potassium sulfate, potassium chloride and gypsum gave little or no control compared to the untreated control. At 10 weeks after first mow, treatments with Insignia and the high rate of sulfur were still effective but all other treatments were either marginal or not different from the untreated control. Results show that applications of Insignia at first mow are effective for severe early season disease, and extended intervals of Insignia applications give effective long term control. Results also show that treatments of Bermudagrass with elemental sulfur reduced disease dramatically indicating that preventive chemical applications before overseeding may be possible.
A Comparison of the Firstline and Sentricon Termite Colony Elimination Systems Efficacy on Heterotermes aureus in Southern ArizonaFirstline® and Sentricon® Termite Colony Elimination Systems were monitored at 20 residential home sites in Tucson, Arizona for their ability to control Heterotermes aureus (Snyder) infestations. Firstline® and Sentricon® Termite Colony Elimination System were each installed at 10 homes. Five of the homes were designated either as curative (having active infestations) or preventative (having no active infestation). During the 2 year study, 3 residents terminated their involvement in the Firstline®, while all of the Sentricon® Termite Colony Elimination System homes remained in the program. Mean number of days to first hit at curative homes was 84 versus 96 for Firstline® and Sentricon® Termite Colony Elimination System, respectively. Average bait consumption for the Firstline® system was 14% for the curative homes and 10% for the preventative homes. In contrast, the average bait consumption for the Sentricon ® Termite Colony Elimination System was 51% for the curative homes and 58% for the preventative homes, which was significantly different at (P<.05).
Survivability of the Subterranean Termite Heterotermes aureus When Exposed to Different Temperatures and Relative HumiditySurvivability of Heterotermes aureus (Snyder) was tested under varying temperature and relative humidity regimes in laboratory incubators over seven day periods. Initial tests showed that RH had a strong influence on H. aureus survival. Survival was significantly higher (P<.05) at 90% RH than 50% RH when held at a constant temperature of 29.4°C. Four temperatures were tested at a constant RH of 90%. Survival was highest at temperatures of 19.4°C (91.8%) and 21.1°C (97.3%). Survival was significantly lower for the higher ranger temperatures of 29.4°C (91.2%) and 32.2°C (69.2%).