Diamond Zoysiagrass Golf Green Response to Reduced Light Environments with the Use of Trinexapac‐Ethyl

Abstract

A 2‐yr study was conducted to determine the tolerance of a mature Diamond zoysiagrass [Zoysia matrella (L.) Merr.] golf green to reduced light environments (RLE) treated with trinexapac‐ethyl (TE) at 0 and 0.013 kg ha−1 wk−1. Three levels of RLE, 0, 60, and 90%, were imposed to coincide with maximum seasonal growth of zoysiagrass. Plant growth measurements included turf quality (TQ), chlorophyll concentration, clipping yield, and total nonstructural carbohydrates. Zoysiagrass grown in full sunlight and 60% RLE maintained commercially acceptable TQ (≥7) with and without TE throughout Year 1 while 90% RLE treatments fell below an acceptable level 2 mo after study initiation. Sixty percent RLE treatments without TE demonstrated unacceptable TQ during Year 2. Application of TE sustained turf viability in 90% RLE through Year 2. Clipping yield increased in 60% RLE without TE compared to full sunlight treatments. Application of TE to 60% RLE treatments reduced clipping yield 30 to 76% in Year 1. Chlorophyll concentration in 60% RLE treatments was similar 10 wk after RLE implementation compared to full sunlight treatments in Year 1 and higher in Year 2. Total nonstructural carbohydrate concentration of roots, rhizomes, and stolons was similar in full sun and 60% RLE treatments at the end of both years and between 47 and 100% lower in 90% RLE treatments compared to full sun treatments. These results support the use of Diamond zoysiagrass in up to 60% reduced light putting green environments with concurrent use of a gibberellin biosynthesis inhibiting product such as TE.