Tifgreen bermudagrass (328) has been used for greens in the Southwest for 40 years. Decreased mowing heights desired for tournament events can result in loss of turf quality and performance. A series of mowing and rolling events were devised and executed on a Tifgreen turf mowed at 5/32", in order to minimize the potential negative affects of a reduced mowing height of 1/8". All treatments were executed prior to mowing the turf at the new reduced height of 1/8". Significant treatment effects resulted from combinations of mowing and rolling for ball speed distance, when averaged over three evaluation dates. When averaged over all three evaluation dates, the single mow/no roll treatment [1x mow/0 roll] had the least ball roll distance (BRD) values. Mowing/rolling combinations which resulted in either three or four operations on Day 1 (1x mow/2x roll, 2x mow/2x roll and 2x mow/1x roll) had slightly greater BRD values than the operations which included two operations (2x mow/0x roll and 1x mow/1x roll). BRD values decreased from Day 1, Day 2 and Day 4 from 81.2", 80.3" to 73.4", respectively when average over all treatments. Single mowing at 5/32", followed by either a double or single rolling event prior to mowing to the new height of 1/8" on Day 1, resulted in the longest BRD values for Days 1 and 2. The effect of all cultural management treatments was diminished by Day 4.

PROXY (ethephon) and PRIMO (trinexepac-ethyl) were applied to ryegrass (as overseeded turf) in winter and early spring of 1999. PGR effect was assessed as reduction in clipping weight between mowings on eleven harvest dates. From March to April, the greatest percentage reductions were realized from all PGR treatments. Over the entire test period (March 5 to May 15), clipping reduction was rate dependent for PROXY with the 10.0 ounce rate producing a greater PGR effect (less clippings than that of PROXY at the 5.0 ounce rate). PRIMO treated turf (at the highest label rate of 1.0 ounce/product/1000 ft) generally produced the greatest clipping reductions, but lost affect in the middle of May when suppression (broke) was released. PROXY at the 10.0 ounce rate was closer to that of PRIMO for PGR effect than was PROXY at the 5.0 rate. All treatments produced less clippings than that of the control on nine of the eleven harvest events. PRIMO produced on average a noticeably darker color turf than PROXY treated turfs and that of the control plots as well. PROXY treated turf at the 10.0 ounce rate generally had similar overall quality turf when compared to PRIMO treated turf throughout the test. This was due to a high degree of plant uniformity among PROXY treated turf, versus the darker color enhancement realized from PRIMO. No PGR affected the initial stages of spring transition from ryegrass to bermuda by late May 1999.

Spring transition of ryegrass back to the underlying bermudagrass has become problematic for turfgrass managers in the Southwest. This is in part do to increased heat tolerance and shoot densities of newer ryegrass cultivars which predominate the market place. The chemical ethephon (Proxy for turf) was evaluated for use as a plant growth regulator (PGR) to enhance transition from perennial ryegrass to bermudagrass. Proxy was applied at either 5 or 10 ounce rates/1000 square ft, either before, during or after soil moisture stress was imposed on the overseeded turf. On the dates of July 6, 21, 19 and August 9 the greatest visible difference occurred among treatments for percent bermudagrass. These responses were not not statistically significant, however. The greatest transition response was achieved (in general) from Proxy applied at 10 the ounce rate, when applied "pre-stress". This treatment combination generally ranked highest for percent bermudagrass throughout the test. The second most beneficial treatment (in general) was that of Proxy at the 10 ounce rate when applied under "medium stress". From July 21 to August 9 this treatment essentially ranked second for the ryegrass to bermudagrass transition. The third most beneficial treatment (in general) was Proxy applied at the 10 ounce rate , applied "post stress". This treatment was applied the latest in the season ( June 16), which was 22 days after the entire test was fully irrigated (at the start of the test on May 23). Proxy applied "post stress" at the 10 ounce rate excelled in enhancing the ryegrass to bermudagrass transition from July 21 to July 29. When applied at either the 5 or 10 ounce product rates, the "low stress" application treatments had minimal affect for transition. These treatments ranked similar in response to that of the untreated - well watered controls. The "medium" stress plots receiving Proxy exhibited a greater affect on the ryegrass to bermuda transition, depending on the date of bermudagrass evaluation. Further testing should be conducted on lower mowed perennial ryegrass with a more aggressive underlying bermudagrass base, such as the popular Tifway 419.

The transition from perennial ryegrass back to bermudagrass is often problematic. Prolonged periods of ryegrass persistence and/or loss of complete turf is troublesome and not favorable to the reestablishment of the bermudagrass base. A group of select herbicides were applied in May 2000, to assess their response to enhance the removal of perennial ryegrass, and to enhance recovery of the bermudagrass. CORSAIR (Chlorosufuron) applied at 1.0 ounce/product/acre resulted in reduced turfgrass quality from three to six weeks after treatment, with a decrease in color at three weeks. This treatment caused moderate suppression of the turf and an enhanced transition from perennial ryegrass to Tifway (419). MANOR (Metsulfuron) applied at 0.4 ounce/product/acre caused a slight growth suppression, acceptable turfgrass color, but a noticeable decrease in turfgrass quality up to six weeks after application. MANOR increased turf density and minimized scalping by seven weeks after treatment (July 24, 2000). SURFLAN when applied at 1.5 lb AI/A, produced acceptable quality turf, no visible growth suppression, acceptable overseed turf quality and color. SURFLAN did not provide any affect as a transition agent in this test. KERB did not greatly enhance transition, and was slightly more effective at 0.5 lb AI/A, than at the 1.0 lb AI/A rate. Both rates of KERB produced acceptable turfgrass color throughout the test. Turfgrass quality diminished to low levels from July 18 to July 24, ranking lowest in quality. KERB treated turf tended to "scalp" more than other treated turfs and thinned the grass at the high rate of 0.50 lb AI/A. FIRST RATE applied at 75 grams AI/hectare caused slight visible suppression for two weeks after treatment, an acceptable quality turf (on six of seven evaluation dates), acceptable turfgrass color and turf density. FIRST RATE did enhance transition, but less so than CORSAIR, possibly less than MANOR, and certainly less than AEF 130630. PROXY was applied on four dates (four, three, two, and zero weeks prior to June 3), selected as a "calendar target" dates observe transition. PROXY when applied on May 13, provided a short transition effect, for a period of about two weeks. Applications made later had little effect whatsoever, on Spring transition back to bermudagrass. From May 19 to June 5, the two "early" applications of PROXY, generally increased turfgrass color and quality scores, most likely by having a PGR response on perennial ryegrass. AEF 130630 readily enhanced Spring transition from perennial ryegrass to Tifway (419) bermudagrass, especially in May and June. All three application rates caused visual suppression of the turf from May 19 until June 5. Turfgrass color and quality were affected by AEF 130630. The maximum expression occurred for the 0.42 ounce/product/M rate by May 25 (which remained until at least June 5). Mean color scores here were 5.3, on both dates. The high rate 0.64 ounce/product/M actually caused less color reductions in the turf (perhaps as a function of the quicker removal of ryegrass). Reduced turf quality resulted three weeks after treatment for both the low and high rates (means = 5.0). The turf was similar to that of the control plots, afterwards, and superior by both middle and late July time periods.

Three slow release fertilizers were evaluated (Contec O.M. Scotts) for turfgrass performance on an overseeded Tifway bermudagrass green from May to October 1998. Products were applied on four dates at the rate of 0.5 and 1.50 lbs. actual -N- per thousand square feet. All fertilizer regime showed little response from June-July for turfgrass clippings, color and quality. After July, differences in color and clippings were detected on X out of X evaluation dates. In general, release/conversion responses occurred approximately one month after application. When coupled with subsequent series applications, the combination of released nitrogen with the water soluble component (approximately 10%) caused the greatest turf response. Clipping production was greatest for the X at the rate of X. Transition from ryegrass to bermudagrass was not affected by fertilizer rate. Additional rates should be tested to investigate seasonal performance of these fertilizers on bermudagrass turfs.

Dimension herbicide (dithiopyr) was applied to common bermudagrass turf at 90, 60, and 45 days before fall overseeding to measure the efficacy for turf safety and for control of fall germinating POA Annua (PA). Applications were made at 0.25, 0.375, and 0.50 lbs. AI/A on each date. One half of each plot was overseeded, while the other half was not. Percent plot (PA) infestation and percent weed control was more greatly affected by the process of overseeding, than that of the herbicide applications alone. When not overseeded, the bermudagrass turf had a maximum of 45% PA control in November, which decreased dramatically to little or no control from January to March 2000. With the inclusion of ryegrass overseed, the high rate (0.50 lbs. AI/A) applied closest to the overseeding (45 DBOS) provided between 79-82% PA control over the length of the test. Actual infestation levels among non-chemical receiving control plots showed a 3X increased level in PA suppression due to overseeding, when compared to the non-overseeded, non-chemical controls. Dimension herbicide alone had little effect for PA control. When combined with overseeding, the 0.50 lb. AI/A rate, applied at 60 or 45 DBOS provided the greatest levels of PA control. The performance of Dimension on non-overseeded bermudagrass does not support the anticipated use of this chemical for PA control.

Increased demand for golf course greens with fast ball speeds and aesthetically pleasing turf present the greatest public pressures that golf course superintendents face today. In the desert southwest, the annual summer monsoon rainfall pattern brings increased atmospheric humidity which results in an increase in the tendency of SR1020 creeping bentgrass to build-up thatch. The effects of four different cultural practices on color, quality, thatch, and ball roll were evaluated on a SR1020 creeping bentgrass green built to USGA specifications grown in an arid environment during a period of increased atmospheric humidity and rainfall. Plots that were verticut/topdress once every two weeks showed unacceptable color, quality, and ball roll. Rolling twice a week had no significant impact on color, quality, and thatch, however, rolling did have a slightly positive impact on ball roll. Grooming three times per week had no significant impact on thatch reduction, and resulted in decreased color, quality and ball speed. Topdressing one time per week did decrease the natural tendency of thatch build-up in SR1020 during periods of increased atmospheric humidity. Topdressing one time per week slightly increased color, quality, and ball roll.

A test was devised to investigate a forced spring transition from perennial ryegrass, back to Tifway (419) bermudagrass with scalping as the main treatment. Scalping of the turf was combined with various nitrogen and aerification treatments performed initially on May 22, 1997. Turfgrass aeration, either with or without extra nitrogen applications, when combined with an initial scalping operation, did not enhance bermudagrass transition by twenty-eight days after treatment (DAT), at the end of June 1997. Turfgrass color, quality and density were adversely affected from initial aerification treatments, especially when combined with initial scalping, The turf recovered best from multiple applications of nitrogen (applied at scalping and again at 7DAT). Turfgrass density (visual estimates) showed that in conjunction with scalping, two applications of nitrogen, totaling 1.5 lbs./month, without aerification, provided a dense turf at 16DAT, which was second only to the untreated control plot. At 27 DAT, scalping + N + N + aerification treated plots had the highest estimate of visual density, eventually showing a benefit from aerification. Scalped and aerified turf alone (no nitrogen) had unacceptable turf density at 16DAT and 27DAT. Generally, two 0.75 lb./N/m applications with aerification proved beneficial over the single application of nitrogen plus aerification, when both turfs were initially scalped. Although non-significant statistically, the additional treatment of nitrogen provided 10% more bermudagrass cover than the single application of nitrogen, for turfs both overseeded and scalped. Scalping alone, plus a single application of N, produced 33% less bermudagrass by June 30, then that of the untreated control.

In six field experiments that were conducted during the spring of 2004 with seven sulfonylurea herbicides for removing perennial ryegrass from bermudagrass turf, the most rapid response and effective ryegrass removal occurred with the latest applications made in June compared to applications made in April or May. Flazasulfuron, foramsulfuron, rimsulfuron, trifloxysulfuron, and chlorsulfuron were effective in removing most of the ryegrass. Sulfosulfuron and metsulfuron were least effective for removing ryegrass, especially during the cooler April and May timings.

Aquatrols surfactant ACA 1848 was applied to Tifway 419 hybrid bermudagrass at rates of 12 or 48 ounces/acre and evaluated for turfgrass growth, performance, and nutrient uptake. Soil samples collected during the growing season were analyzed for inorganic nitrogen (ammonium and nitrate). Only on the last sampling date only (September 29), the soil nitrate-nitrogen level was slightly higher in the untreated control than in other plots. Otherwise, soil nitrogen levels did not differ among treatments. Growth measurements and visual ratings did not differ among treatments at any time during the growing season, indicating that surfactant treatments did not affect either of these parameters. Leaf clippings collected throughout the growing season were analyzed for total nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, sodium, boron, copper, iron, manganese, and zinc. With only one exception, differences in nutrient content among treatments were statistically non-significant at the 5% significance level. That exception occurred on August 18 when the turfgrass treated with surfactant at the 12 oz/a/wk level had less zinc than turfgrass in the 0 or 48 oz/a/wk treatments. There was a noticeable, but non-significant trend, observed as follows; the highest level of surfactant treatment (48 oz/a/wk) resulted in the highest tissue levels of phosphorus, potassium, sulfur, sodium, boron, and copper in samples collected on July 21 (day 203), August 4 (day 217), and September 1 (day 245). Calcium, magnesium, and iron levels were highest in this treatment on August 4, but these differences were extremely small and always statistically nonsignificant and this trend was not observed on other sampling dates. There were no consistent rate trend responses (i.e. where the higher level of surfactant treatment produced a greater response than the lower rate) throughout the test. On all sampling dates, the untreated control contained more manganese than either of the surfactant treatments; the differences were not statistically significant and were not rate related. In this field study, there were no turfgrass responses, either positive or negative, that we could attribute to Aquatrols ACC 1848 applied at 12 and 48 oz/a weekly. The magnitudes of response differences observed in this study were not large enough to identify statistically significant differences.