Survivability 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%).

Rapid 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.

Flazasulfuron 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.

Sequential 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.

Velocity 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.

No 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.

Sequential 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.

The 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.

Certainty, 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.

Use 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.