Golfdom, January 2017

FIGURE 2 Accumulated effects of eight passes with the roller in the morning right four passes with the roller in the morning middle and 0 passes with the roller in the morning left after 15 traffic applications on a Crenshaw creeping bentgrass research putting green on Feb 15 2015 during the 2015 winter season K fertilization increased the concentration of K in leaf tissue and improved load bearing capacity and leaf tensile strength Additionally K fertilization reduced tissue water content This and other research led to the conclusion that K plays a critical role in the improvement of wear tolerance in creeping bentgrass Other studies however have shown contradictory trends on other turfgrass species and selected studies on creeping bentgrass K had little to no effect on Kentucky bluegrass seashore paspalum perennial ryegrass or creeping bentgrass wear tolerance As with the trend demonstrated with nitrogen N alone the effect of different N K ratios 1 1 and 2 1 on wear tolerance varied among species TEMPS VERSUS ICE Low temperatures dont necessarily cause freezing injury Instead ice formation resulting from low temperatures is responsible Intracellular freezing the formation of ice crystals within cells resulting from a rapid temperature drop often is lethal because the ice crystals rupture cellular membranes And more often temperatures drop more slowly and ice forms between cells extracellular freezing This freezing can slow cel lular reactions and metabolic processes but usually is not lethal unless the ice CART PUSHING FOR SCIENCE Low temperatures dont necessarily cause freezing injury Instead ice formation resulting from low temperatures is responsible This freezing can slow cellular reactions and metabolic processes persists for extended periods of time or the ice is manipulated in a manner so that crystals rupture cell membranes such as when traffic occurs on frostcovered turfgrass Our study concerning the performance of a creeping bentgrass putting green was conducted to investigate the effect of fall applied K in combination with traffic applied at 8 a m when frost was present during the winter MATERIALS AND METHODS A field experiment was conducted from Oct 1 2014 to April 30 2015 and Oct 1 2015 to April 30 2016 on a Crenshaw creeping bentgrass putting green established in 1997 to USGA guidelines with an 85 15 sand andpeat moss root mixture at Clemson S C Treatments consisted of three K rates 0 075 and 15 lbs K per 1000 sq ft three morning traffic rates zero four and eight passes with a modified water filled push turfgrass roller weighing 165 lbs and an applied force of 027 lbs per sq ft and two afternoon traffic rates zero and six passes with the same roller The K fertilizer used was 0 0 30 Brandt 30K Brandt Consolidated Inc and the fertilizer contained 30 percent soluble potash K 2 0 We applied fertilizer treatments three times over the course of a one month period to minimize potential for fertilizer burn from a single application at rates of 025 and 05 lbs K per 1000 sq ft each fall to reach the total desired supplemental K rates of 0 075 and 15 lbs K per 1000 sq ft K fertilizer application dates for year one were Oct 10 2014 Oct 24 2014 and Nov 12 2014 while fertilizer application dates for year two were Oct 8 2015 Oct 22 2015 and Nov 5 2015 We made K fertilizer applications as foliar applications in the late afternoon with a CO 2 backpack sprayer and they were lightly watered Continued on page 40 January 2017 Golfdom 39 Golfdom com