Kentucky bluegrass (Poa pratensis L.), cv. Nu Star was studied in a greenhouse to evaluate its growth responses in terms of shoot length and dry weight under NaCl (sodium chloride) salinity and different levels of Trinexapac-ethyl( primo Max). Plants were grown hydroponically under control and one level of salinity [EC (electrical conductivity) of 5 dS/m] and three levels of primo Max (0.3, 0.6, and 0.9 oz/1000 ft²), using Hoagland solution No. 1. Plant shoots (clippings) were harvested weekly, oven dried at 60 oC, and dry weights recorded. At each harvest, shoot length was measured and recorded, percent visual canopy green cover was also estimated. The results show that shoot length and shoot dry weight (DW) of Kentucky bluegrass significantly decreased with both salinity and primo treatments, although the differences in shoot length and shoot DW were not significant between primo treatments at 0.6 and 0.9 oz/1000 ft² application rates. The green coverage of the turf canopy decreased under salinity stress, and the reduction of green canopy coverage by salinity was more pronounced when turf was treated by primo, suggesting that primo significantly reduced the salt tolerance of Kentucky bluegrass. The above results were observed for both cumulative as well as the weekly growth responses.

No description available.

The ET rate of bermudagrass is relatively well known. The ET rate of Seashore paspalum in an arid environment is not, nor is there any information on the ET of Distichlis as a mowed turf. A greenhouse test using gravimetric lysimeters was conducted in the late summer of 2004 to measure and compare the ET of two Distichlis clones and Sea Isle 1 seashore paspalum to that of Tifway 419 bermudagrass. This test showed that under glass house conditions when soil moisture was not limiting: (1)Seashore paspalum had a higher ET rate than A119 saltgrass in terms of mm/day, and total consumptive water use for the 19 day test period, (2) A48 saltgrass and Tifway bermudagrass had similar daily ET rates and similar total water use, (3) total water use between two select saltgrass clones was not significantly different . Saltgrass A48 and A119 had a total consumptive water use of 84.2 and 76.5 mm, respectively over the 19 day test period. Tifway Bermuda totaled 82.2 mm, and Sea Isle 1 used 92.1 mm over 19 days.

Sixty-four overseed turf entries were evaluated from October 2002, to June 2003 for turf when overseeded on Tifway bermudagrass fairway turf. Overseed entries included 43 single variety (or experimental synthetics) of perennial ryegrass, 2 annual ryegrasses, 6 entries of intermediate or 'hybrid' ryegrass, 5 entries of Poa trivialis (PT), one blend of perennial ryegrass, 4 mixtures (two or more species together) and 3 fescues. The main effect of "overseed grass entry" was highly significant on all dates for all visual turf responses, which included establishment, color quality, density, texture, and spring transition. The greatest amount of variation occurred within the perennial ryegrass group as a whole, showing the diversity within this species for overseeding performance. Annual ryegrass provided quick germination and ground coverage in the fall and a quick spring transition, but was of poor turf quality. Intermediate ryegrasses had performance values between that of perennial and annual ryegrass, some of which provided moderately good turf performance and good transition. Poa trivialis was slow to establish, but provided good quality and excellent plot texture, however they had poor transitional qualities. Final quality mean scores ranged from 3.0 (P-02-0047 PT) to 7.7. There were three entries, which averaged 7.7 at the close of the test, which included Mach 1 PR, SR 4500 PR, and Pace PR. The entries IG-2, Greenville PR, Express PR, Bar LO 2001, Hawkeye, Partee finished at 7.3 for quality. Among the intermediate ryegrass entries, Froghair finished with a mean quality score of 7.0, followed by Pick 00- A-LH (5.3). All three fescues produced mean quality scores of 6.0 or better on 8 June (Hardtop fescue leading at 6.7 for quality). The Labarinth tall fescue did have 62% Bermuda at the end of the test, compared to 65% for all entries at that time. Entries which had a mean quality score of 7.0 or more in June, along with a bermuda transition of close to 75% or more at the termination of the test included the following entries; Citation Fore, Mach 1, BarGold, Bar LP 2001, Pace, Greenville OSP, and Express.

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.

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.