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.

The 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.

The 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.

Severe 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.

This 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 60° 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.

Various saltgrass (Distichlis spicata) clones were studied in a greenhouse to evaluate their growth responses in terms of shoot and root lengths and shoot and root dry matter (DM) weights under salt stress. Plants were grown hydroponically using Hoagland solution No. 1. Treatments included control plants and plants grown with salt (NaCl) at EC of 20 dSm⁻¹. Twelve different clones were grown with four replications of each variety. Plants were grown in a randomized complete block (RCB) design. Plant shoots (clippings) were harvested weekly, oven-dried at 60° C and DM weights were recorded. At the last harvest, plant roots were also harvested, oven-dried at 60°C and DM weights were determined and recorded. The results show increased shoot length in control plants, increased root length in most of the plants grown in saline conditions, greater shoot dry weight in control plants and greater root dry weight in saline plants. All results for shoots are based on a weekly average for six weeks and for roots are based on an average of the four replicated clones at the end of the study.