Hydro-Gro ( 10-0-0) and UAN 32 (32-0-0) were applied once every 10, 15 or 30 days on a bermudagrass green overseeded with Poa trivialis at the rate of 9.0 lbs. PLS/M in mid October, 2007. Regardless of application frequency, each product was applied to achieve a 020. lb./N/1000 ft² nitrogen rate. Hydro-Gro produced a darker green turf than did the UAN, when averaged over all application timings. Enhanced turfgrass color was more consistent when Hydro-Gro was applied every 15 days (2x/monthly) compared to the 10 and 30 day application timings of this product. For the UAN source, no single application timing scheme produced a consistently darker Poa trivialis turf compared to any other application timing for the same product. Turfgrass quality was slightly greater on average for Hydro-Gro than that of the UAN treatments, although each source produced a better quality turf at one time or another within the two month application / evaluation period (Nov 15, 2007 to Jan 3, 2008). The addition of supplemental P and K did not enhance visual color or quality for either of these N source products from November to early January. Neither N source, their application timings, or the addition of supplemental P and K had any affect on turfgrass density, texture or overall uniformity.

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 warmseason 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.

Spring transition (from ryegrass to bermudagrass) has been problematic for the last 20 years based on, in part, improved heat tolerance and lower growing cultivars of perennial ryegrass. Annual ryegrass is used sparingly for commercial properties and for home owners in southern Arizona. Hybrid ryegrass (cross between perennial and annual ryegrass) has been manufactured by seed companies in an effort to improve the transition of a grass used specifically for overseeding, with improved turf grass attributes over those of annual ryegrass. A field test was conducted to evaluate several hybrid ryegrasses, two improved annual ryegrasses, and Gulf annual ryegrass under homeowner conditions. The true annuals produced the quickest amount of ground cover in the shortest period of time. By early December, all plots had 98% or more cover, with FH having 95% cover. Transend, Transport and 041 Lh had consistently high quality scores throughout most of the 8 month test, with Transport and 04 1 LH scoring for fair turfgrass quality into mid June. Sprint annual ryegrass had excellent turfgrass quality scores in November and December, however, scores declined substantially in April and afterwards. After emergence and into early December, Transport and 041LH clearly had the darkest turf coloration, with 041LH producing a turf with a color intensity typical of medium green perennial ryegrass. Gulf and FH were noticeably lighter in color. Gulf, Sprint and Transcend developed ring/patch type disease symptoms in early February 2007, while others did not. "Stemminess" ratings in late spring (a time at which annual ryegrass is typically pronouncedly so) showed that FH intermediate and Gulf produced the most "stemmy" turfs, followed by Sprint annual. Transport and 041LH showed hardly any seed head culm development, with Transcend being intermediate. Interestingly, not all the entries which generally had the highest numerical rankings for density, texture, uniformity and overall turfgrass quality, had the highest percent plot living overseed during transition. Entry 041LH had 30% overseed, 46% bermuda, and 24% straw. Transcend had 16% overseed, 25% straw and59% straw on June 12. Transport had the highest retention of green overseed (72%), with 23% bermuda and 5% bare ground or straw plot cover. Sprint had 19% overseed, 20% live bermudagrass, and 61% bare straw plot cover, more so than that of Gulf. Final quality scores showed that 041LH and Transport had the best quality mean rank values, with all others having low quality scores on 12 June just prior to scalping to fully reconstitute the underlying Tifway bermudagrass. This shows vast improvements in turfgrass performance for INTERMEDIATES, which previously (and again) show near full acceptability in most turfgrass attributes, and now show enhanced color. Likewise, improvements in strict annual types show improved turf quality (Sprint) over Gulf.

Forty nine seeded entries were overseeded into Tifway bermudagrass maintained at 5/8" inch. Improved annuals showed better turf performance in most categories than GULF annual, while hybrid(intermediate ryegrasses) showed great improvement over original release material. Annuals and hybrids were more vigorous in plot establishment after emergence until late November/early December, when perennial types increased plot cover. Poa trivilais was slower to emerge than other grasses, but had excellent performance in the coldest parts of the winter season, only to decline early in the spring for overall turfgrass quality. Turfgrass color scores were greatest on 17 February and 27 March. On 17 February, the mean color scores ranged from a low value for Gulf annual (4.0), to the Jacklin blend which averaged 8.5 (Table 3). Other darker entries included the PHD blend (8.0), B-5.1095 ryegrass (8.0), B-6.1523 ryegrass (8.0) Pick EJ ryegrass (8.0), B-6.1523 (8.0), Brea ryegrass (7.8), Pavilion ryegrass (7.8), RX ryegrass blend (7.8), Acapella ryegrass (7.8) Ringer II (7.8) and PM 102 ryegrass (7.8). Physical mowing stress was evident on 2 May, in which grasses exhibited leaf tip shredding and elongated flowering culms. Gulf and Panterra annual aul ryegrass showed the least favorable mowing response. STR 4NV (intermediate ryegrass ) had mow stress-type symptoms similar to perennial ryegrass, which was much less than that of the annual types. On 19 June, bermudagrass plot cover ranged from 17.5% (Laser PT) to 100% cover on several other entries. The Rx ryegrass blend, Bar LM TL annual ryegrass, Leaguemaster blend, and Heat PR all had 100% bermudagrass cover. The non-overseeded checks had 95% bermudagrass on 19 June. There were nine entries with 90% or more bermudagrass, ten entries that had 80-85% bermuda, four entries that had between 85-90% Bermuda, and sixteen entries with 75% or less bermudagrass on 19 June. The Champion Fine mixture had 55% bermudagrass. PHD had 63%. Pavilion had 63% bermuda as well. The Poa trivialis entries had the least amount of bermudagrass present. Entries which had high quality scores on average throughout the entire test period (early November to July 12 included the entries, Champion RB (mixture of creeping red fescue and perennial ryegrass) (6.8) ; Champion GC (mixture of fine fescue and perennial rygrass) (6.8) ; the experimental ryegrass B-6.1523 (6.7) ; Jackilin Blend A (6.7) ; the experimental ryegrass B-6.1091 (6.9) ; and B-6.0756 (6.8) ; Entries which had generally throughout the entire season had good quality and high amounts of bermudagrass on 19 June included Heat (100%), STR 4TPC (93%), STR 4QT (90%), RX (100%), Jacklin Blend A (88%), B-6.1095 (95%), and Champion STF (98%). Other entries had a quicker transition, but had lower mean quality scores otherwise, while others had high quality scores, but a slower transition.

Overseeding bermudagrass with a cool season grass species is often necessary because of cold temperature dormancy (to bermudagrass) realized in the overwhelmingly large majority of winter seasons. Forty (40) entries of either perennial, annual, or hybrid ryegrass cultivars, blends and species mixtures, were evaluated for season long overseed performance under semi-arid conditions over Tifway bermudagrass mowed at 5/8". Treatment "mean squares" were statistically significant on all evaluation dates for turfgrass color, quality, density, texture, and percent canopy composition. Entries differed in mean quality performance based on the time of year (fall, winter vs. spring). Entries with high fall/winter quality scores included Cutter II perennial ryegrass, Dasher III perennial ryegrass, PST-2TQL perennial ryegrass, PST- 2TQL perennial ryegrass, Revenge GLX perennial ryegrass, 7.0516 perennial ryegrass, DGA ryegrass blend, Derby, 03 PT-3 Poa trivialis, and Palmer V. Entries which ranked highest for spring performance included New Arrival, Palmer GLS, L4O-6-XLT-1, Patriot 4, Overture blend, Shining Star, and 041- LH. Entries which ranked highest for year round quality included New Arrival, Palmer V, Palmer GLS, 03PT3 Poa trivialis, PST-2TQL, Overture blend 042LH hybrid ryegrass, and Top Gun II. Entries which had an early and strong transition as well as good quality prior to and including the transition included the following: Patriot 4, Shining Star, L040-6-XLT-1, 04-2 LH hybrid ryegrass, Applaud II, 7.0156, Revenge GLX, SPT-2T QL, Palmer 4 and New Arrival.

Five hybrid ryegrasses were evaluated as low maintenance turfs against Gulf annual ryegrass an one turf-type perennial ryegrass, when mowed once a week at 2.75 inches. Among four improved hybrid ryegrass entries, several hybrid ryegrass entries did not statistically differ from the dark perennial ryegrass color as hybrid 05 ABL maintained dark color throughout the test from November 2007, to late April 2008. The entries 05 ABD, 04-1 LH and 04-2 LH all provided nominally dark color turfs, which held good color even up to the end of April. At a seed rate of 625 lbs PLS/acre, all entries produced acceptable "dense" turfs, with the exception of Gulf annual. The hybrids 05 ABL and 04-2 LH produced very dense turfs, with high apparent shoot densities very similar to that of perennial ryegrass. Both 04-1 LH and 0 5 ABD hybrids also produced satisfactory turf densities as well. While the perennial ryegrass "American Star" had very narrow leaves, the hybrid 04 2 LH also had fine leaves throughout the season. Hybrid 05 ABL was also fine textured. After emergence, 04-1 LH hybrid had somewhat wider leaves than some of the other hybrids, but it produced finer leaves shortly afterwards until the close of the test. Measured leaf widths ranged from 1.4 to 2.7 mm in February under peak performance conditions of growth and weather. American Star perennial ryegrass ranked highest for quality on most occasions, but was often included in the same statistical mean performance grouping (within the same LSD value range) with the hybrid entries of 04-2 LH, 04-1LH, 05 ABD, and 05 ABL. Froghair was generally better than Gulf annual in quality, while the check plots (nonoverseeded) showed green up by late April. At mid June, both Gulf annual and Froghair hybrid ryegrass had the least amount of overseed present, but the bermudagrass was not filling in quickly as other hybrids which had more bermudagrass cover present and less straw (from dead overseed) present. This was true for hybrids 05 ABL (41% bermuda: 13% straw), and 04-1 LH (25% bermuda: 11% straw). Therefore, there are hybrid entries which show better transition than Gulf annual, and at the same time produce lesser amounts of lingering necrotic tissue at transition.

Tenacity herbicide (mesotrione) was evaluated for use as both a pre-emergent and post- emergent herbicide in conjunction with fall overseeding of bermudagrass with perennial ryegrass. Tenacity herbicide, when applied @7 DBOS, 1 DBOS, at first mowing (2 WAOS) or 3 weeks after the first mowing (5 WAOS) did not cause a reduction in stand of perennial ryegrass compared to non-treated controls. There was essentially no difference in ryegrass emergence and cover for Tenacity when applied at the 2.0 oz. versus the 3.0 oz AI/A rate. When applied at these rates at both 7 DBOS and at the first mowing, treatments 1, 3, and 6 produced similar results. Overseeding occurred on October 16, 2007. Intense Poa annua pressure dominated the overseed ryegrass by late December, causing a decline in existing ryegrass cover. Only the latter applied treatments (of Prograss, or tank mixes which contained Prograss with Tenacity) regained sizable amounts of ryegrass by the end of February and early March. Percent weed control was ineffective for treatments which did not include Prograss herbicide. The split application of Prograss of 0.75 lbs AI/a applied @ 8 WAOS and again @ 12 WAOS resulted in the greatest amount of Poa annua control, and the greatest amount of ryegrass. Tenacity (mesotrione), when applied at rates and timings observed here, was safe for perennial ryegrass emergence, but ineffective on Poa annua pre-emergence and as a post emergent agent based on the subsequent growth of Poa annua.

Velocity herbicide was applied alone, or with mixtures of Tourney fungicide and/or Primo PGR for the post emergence control/suppression of Poa annua (var. annua) in bermudagrass overseeded with perennial ryegrass. When applied alone as a repeat applications, Velocity herbicide applied at 15 and 30 gm ai/a was safe on perennial ryegrass overseed (based on color response). Velocity was safe for the overseed ryegrass when tank mixed with Tourney fungicide, both with and without the addition of Primo PGR. Tourney fungicide when applied alone at either 8 or 16 oz./product/acre produced no negative affects. As expected, Primo alone produced a dark color turf (7.8, 7.5, 7.0, and 7.0) on all four dates, respectively. Several treatments caused moderate injury to the (AB) across the entire test period. These included Velocity alone at the 15 gm/ai/a rate, and Velocity @ 30 gm ai/a plus Tourney @ 8 oz.prod/acre. The greatest amount of injury to (AB) occurred on 3/11/2008 for Velocity at 30 gm ai/a, either with or without Tourney fungicide. Although visible injury to Poa annua resulted after treatments were applied, seed head suppression was the most consistent treatment response. While injury to the Poa was severe for some treatments (Velocity plus Tourney fungicide), the Poa annua did return, ranging from re-growth as "weak plants" to an actively growing turfs (as is sometimes typical after a surviving injury response). Based on results, perhaps a tank mix application of Velocity at 30 gm ai/a along with 8 oz. product/acre of Tourney and 6 oz./acre of Primo, followed by a repeat application 35 days later may provide the ultimate seed head suppression.

For pre-emergence control of Poa annua (PA), Dimension as the EC and 270 G (granular) formulations were applied either as single applications at 6 and 8 weeks before fall overseeding, followed by sequential applications of Barricade. Barricade was also applied 6 and 8 weeks before overseeding. The plots were overseeded on October 2, 2006 with a Citation III perennial ryegrass blend at the rate of 625 lbs PLS/A. When overseeded with perennial ryegrass: Both pre-emerge treatments of the 270G formulation, and Barricade applied at 0.77 lbs AI/A six weeks before overseed (6WB0S) had moderate to severe stunting. Both Dimension treatments (6 and 8 weeks BOS) had no apparent loss of vigor, and were equal in vigor with that of the non-treated turf. By mid December , the 270G treatments produced the least amount of ryegrass cover. Also on October 18, there was a slight reduction in ryegrass cover for Dimension and Barricade treated turfs. The single application treatments of Dimension produced slight/moderate percent weed control in February and March, which declined rapidly by the end of March. On March 15, Dimension applied at 32 ounces/product/acre at 6 and 8WBOS had a season maximum of 43%, and 20% weed control, respectively. Barricade applied at 0.77 lbs. product/A had the highest amounts of PA control realized in this test. The pre/post application of Barricade (alone) produced percent weed control values statistically similar to that of the single pre-emergence application of Barricade alone at either 6 or 8WBOS. The 270G treatments produced much higher levels of percent (PA) control than the liquid formulation on all three dates. In non-overseeded turf: Liquid Dimension treatments showed NO control whatsoever at 8WBOS. At 6WBOS, 24% PA weed control was the highest control achieved early on at the November 2 evaluation. Barricade, when applied once as a pre-emergence, had good to moderate percent PA weed control, which declined after December (45% in January) at the 6WBOS timing. The 270G treatments had very good initial weed control (as it did on the overseeded plots) with 93–97% weed control on November 2, 89% - 91% on November 17, and 71-80% weed control on December 7. The affect of overseed alone on suppression of PA was 72%, 60%, and 52% (16 Feb, 15 Mar, and 26 Mar).

TGR (paclobutrazole) was applied to both overseeded and non-overseeded turfs in repeat monthly applications at either 8.0 oz or 12.0 oz product/1000 ft² rates. Applications were made in repeat monthly intervals to apply either three, four or five repeat applications beginning in December 2007, and ending in April 2008. When applied as a post emergent PGR material, TGR caused only a slight decrease in turfgrass color and quality of overseeded turfs in March at the high (and repeated) rate of 12.0 oz/product/acre. This effect was short lived, as overseeded turfs for the remainder of the season maintained fully acceptable color and quality through the spring transition period. Tenacity turfs always had quality scores of 6.0 or higher throughout the test. Seed head suppression was realized from TGR, with greater head suppression at the 12.0 oz rate than that of the 8.0 oz rate. Bermudagrass transition among TGR treated turfs was not different from that of the untreated controls, whether the turfs were overseeded or not. On 20 June 2008, percent bermudagrass plot cover ranged from 29-58% for TGR treated turfs, 40% for Tenacity, while the overseeded UTC had 35%, on average. The percent bermudagrass increased quickly after a 2.0 lb. /N /M application on June 20, to 68% to 90% bermudagrass cover for TGR treated turfs (UTC = 83%). After a scalping event (from 1.25 inches to 0.50 inches) performed on July 1, percent bermudagrass decreased temporarily (from bermudagrass removal), but rebounded within 15 days to yield 96% to 99% bermudagrass cover by the close of the test on 31 July, 2008. Like wise, Tenacity alone did not inhibit transition, as Tenacity treated turfs had bermudagrass cover slightly greater than that of the overseeded controls.