Surface Stability Reinforcement and Measurement Thomas Serensits Penn State University USA
Surface Stability Divoting = complete shearing (removal) of turf root system from rootzone
How to Increase Surface Stability? Stabilize the soil Synthetic reinforcements Artificial root system Improve plant growth Tiller density Rooting
Objective Evaluate the effects of 1) Synthetic reinforcements 2) Multiple application regimes of the plant growth regulator trinexapac-ethyl on the divot resistance of natural turfgrass athletic fields
Synthetic Reinforcement Study High-sand rootzone Perennial ryegrass (Lolium perenne L.) 3 traffic levels June to mid-october Split-block, 3 replications, ANOVA
Turfgrids (3, 5 g kg-1) Nike Reuse-A-Shoe Heavies and Lights(30 g kg-1) Netlon (3, 5 g kg-1) DuPont Shredded Carpet (5, 10, 20, 30 g kg-1)
Sportgrass
Divot Resistance Measurement Weighted pendulum 76 kg weight Pitching wedge head Beard and Sifers, 1990; Adams, 1997 Consistent drop height Measure divot length
Mean divot lengths for the synthetic reinforcement main effect (p<0.01) 450 Divot Length (mm) 400 = Fisher s Least Significant Difference (LSD) at p < 0.05 350 300 250 200 150 100 50 0 Reinforcement
Mean divot lengths for the synthetic reinforcements High Traffic(p<0.01) 450 Divot Length (mm) 400 = Fisher s Least Significant Difference (LSD) at p < 0.05 350 300 250 200 150 100 50 0 Reinforcement
Synthetic Reinforcements Summary Synthetic reinforcements beneficial only after turfgrass cover significantly reduced Healthy root system masked benefits Increasing rates of reinforcement = smaller divots
Plant Growth Regulator Study
Plant Growth Regulator Study Plant growth regulator Reduce vertical shoot growth by altering hormone levels Trinexapac-ethyl (TE) Inhibits gibberellic acid Side effects increased tiller density and rooting www.turffiles.ncsu.edu
Plant Growth Regulator Study High-sand rootzone 9 cultivars of Smoothstalked meadow grass (Poa pratensis L.) 3 traffic levels July to October Strip-split plot, 3 replications, ANOVA TE (0.17 kg a.i. ha-1) application regimes (28day intervals) May through July (3) May through October (6) Cultivation treatment (May) Core aerification Vertical Mowing
Plant Growth Regulator Study Divot Resistance Weighted Pendulum Tiller Density Below-ground biomass Loss on ignition test
Mean divot length values for the treatment main effect (p<0.01) Divot length (mm) Treatment 2006 2007 Control 308 362 TE May-July 252 335 TE May-Oct 278 370 Cultivation 282 341 LSD (0.05) 27 18
Mean tiller density values for each treatment (both years combined) 2000 Tillers m-2 1900 = Fisher s Least Significant Difference (LSD) at p < 0.05 1800 1700 1600 1500 Control TE May-July TE May-Oct Cultivation Treatment
Mean below-ground biomass values for each treatment (both years combined) 85 = Fisher s Least Significant Difference (LSD) at p < 0.05 g m-2 80 75 70 65 60 Control TE May-July TE May-Oct Cultivation Treatment
Plant Growth Regulator Summary TE applied May-July reduced divot size most TE applied May-October and cultivation produced inconsistent results TE applied May-July increased tiller density and below-ground biomass
Conclusions Synthetic reinforcements On high-use, high-sand rootzones, synthetic reinforcements can provide a decrease in divoting Plant growth regulators (trinexapac-ethyl) Preconditioning the turf before use with TE, then allowing a return to uninhibited growth, can decrease divoting
http://ssrc.psu.edu/ College of Agricultural Sciences Department of Crop and Soil Sciences