Tuesday, November 6, 2007
170-1
Use of PGRs to Enhance the Establishment of 'Shadow Turf' Zoysiagrass in Shaded Environments.
Gerald Henry, Bradley Sladek, and Dick Auld. Texas Tech University, Department of Plant and Soil Science, Campus Box 42122, Lubbock, TX 79409-2122
Field experiments were conducted at the Texas Tech Turfgrass Research Farm in Lubbock, TX in the summer of 2007 to quantify the efficacy of trinexapac-ethyl to enhance the establishment of ‘Shadow Turf’ zoysiagrass grown in shade. Plugs (2.5 cm2) of ‘Shadow Turf’ zoysiagrass were transplanted into bare ground on June 15, 2007. Nine plugs were planted in a grid pattern approximately 23 cm apart in plots measuring 1.2 m2. Plots were arranged in a randomized complete block design with four replications. The experimental parameters evaluated included four shade treatments and three PGR (plant growth regulator) treatments. Shade treatments consisted of 0, 30, 60, or 90% shade and were applied through the placement of shade cloth boxes over each plot. PGR treatments were applied at planting and monthly thereafter. Treatments consisted of no treatment, trinexapac-ethyl at 0.048 kg ai/ha, or trinexapac-ethyl at 0.096 kg ai/ha. PGR treatments were applied using a CO2 backpack sprayer equipped with XR8003VS nozzle tips and calibrated to deliver 304 L/ha at 276 kPa. Plug diameters and % cover ratings were taken monthly for each plot. Data was subjected to analysis of variance and, where appropriate, evaluated for interactions. Means were separated using Fisher’s Protected LSD at the 0.05 confidence level. Plug diameter growth and % cover 1 MAIT (month after initial treatment) was greatest for 0% shade, followed by 30, 60, and 90% shade, regardless of PGR treatment. Plug diameter growth and % cover 1 MAIT was greatest when no PGR was applied, followed by 0.048 kg ai/ha, and 0.096 kg ai/ha, respectively. Additional ratings will be conducted through fall in order to determine long-term effects of shade and PGR treatments on ‘Shadow-Turf’ zoysiagrass growth.