Golfdom, February 2017

this without leaving brown spots More information is available at earthcarewithsumagrow com test results golf courses RESULTS Data from the two experiments presented in this article are representative of results from multiple experiments For clarity Im presenting only a single years data for each experiment POA ANNUA CONTROL IN PUTTING GREENS A study was conducted from October 2013 to January 2014 on a 9 year old practice green at Callippe Preserve Golf Course in Pleasanton Calif a suburb of the San Francisco Bay area The composition of the green was about 50 50 Dominant Plus creeping bentgrass and Poa annua Soil was a 90 10 sand peat mix conforming to USGA recommendations Mowing height was 0125 inches A CO 2 powered backpack sprayer was calibrated to deliver an output of 2 gal 1000 sq ft All chemical treatments received 5 minutes of irrigation following application and standard irrigation practices thereafter Plot size was 4 ft x 6 ft with four replications of each treatment Percent Poa annua control was calculated based on Poa annua cover 0 to 100 percent determined at the start of the experiment and every two weeks thereafter Chemical treatment effect was significant on three rating dates Table 1 In general higher rates and more important higher total amounts of PoaCure resulted in the best Poa annua control These results corroborated other findings that at least 48 oz M of PoaCure applied over a period of 10 to 16 weeks is required for optimum Poa annua control on putting greens in California ReeVerse Poa was not effective in reducing Poa annua populations In fact Poa annua increased rather than decreased following applications of this product A FORMIDABLE FOE FIGURE 2 PoaCure 12 oz M 10 12 WAOS Effects of products on Poa annua control in bermudagrass turf overseeded with perennial ryegrass Note Po aCure plot designated by the arrow Toscana Country Club Indian Wells Calif Photo taken March 11 2014 TABLE 1 Treatment Rate oz M Timing Total oz M Control 36 D 79 E 100 E PoaCure 06 ABCDEF 36 21 A 8 ABC 83 A PoaCure 12 ABCD 48 25 A 30 AB 91 A PoaCure 06 A 06 8 ABC 27 CD 40 CD PoaCure 12 A 12 11 ABC 7 CD 29 CD PoaCure 06 AB 12 16 AB 6 BC 4 BC PoaCure 12 AB 24 27 A 9 ABC 14 B PoaCure 06 ABC 18 9 BCD 1 BC 10 BC PoaCure 12 ABC 36 31 A 44 A 69 A ReeVerse Poa ReeVerse Poa 60 30 B CDEFG 21 13 CD 38 D 55 D Application Timing A Oct 10 2013 B Oct 24 2013 C Nov 7 2013 D Nov 21 2013 E Dec 5 2013 F Dec 19 2013 G Jan 2 2014 Percent Poa annua control based on initial Poa annua cover ratings and following sequential applications of PoaCure methiozolin herbicide and ReeVerse Poa in 2013 14 Callippe Preserve Golf Course Pleasanton Calif A negative number indicates an increase in Poa annua population and a positive number indicates a decrease in Poa annua population Percent Poa annua control means followed by the same letter in a column are not significantly different α 005 CONTROL IN OVERSEEDED TURF A study was conducted from August 2013 to March 2014 at Toscana Country Club in Indian Wells Calif The bermudagrass fairway was overseeded with perennial ryegrass on Oct 15 A CO 2 powered backpack sprayer was 11 21 13 12 5 13 1 16 14 calibrated to deliver an output of 2 gal 1000 sq ft Chemical treatments were applied from eight weeks before to 16 weeks after overseeding to evaluate Poa annua control Table 2 Plot size was 4 ft x 6 ft with four replications Continued on page 36 February 2017 Golfdom 35 Golfdom com