Trinexapac-Ethyl and Open-Field Burning Maximize Seed Yield in Creeping Red Fescue

• Published in: Agronomy journal 2006-11, Vol.98 (6), p.1427-1434
• Main Authors: Zapiola, M.L, Chastain, T.G, Garbacik, C.J, Silberstein, T.B, Young, W.C. III
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; application timing; Biological and medical sciences; crop residue management; crop residues; Crop yield; Cropping systems. Cultivation. Soil tillage; dry matter accumulation; dry matter partitioning; Festuca rubra; forage grasses; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; harvest index; plant growth control; plant growth substances; prescribed burning; seed crop production; seed productivity; Sowing and planting; stubble; Tending. Growth control; Tillage. Tending. Growth control; trinexapac-ethyl; Vegetative propagation. Sowing and planting. Harvesting
• ISSN: 0002-1962; 1435-0645
• DOI: 10.2134/agronj2005.0223

Open-field burning, an effective and economical practice for increasing seed yield in creeping red fescue (Festuca rubra L.), has been restricted in Oregon due to air quality and safety issues. The use of the plant growth regulator trinexapac-ethyl [4-(cyclopropyl-α-hydroxy methylene)-3,5-dioxocyclohexane carboxylic acid ethyl ester] (TE) was evaluated as a potential alternative to open-field burning for maximizing yield in creeping red fescue over 4 yr. Fall and spring applications of TE in combination with residue management practices, open-field burning and mechanical removal (flailing) of post-harvest residue, were evaluated to determine potential effects on seed yield and dry matter partitioning. Spring TE applications in burn plots increased cumulative seed yield by 38% over the check. In flail plots, spring TE applications increased yield by 30 and 16% over the burn check for the first 2 yr, but no response was observed later. Open-field burning was critical for maintaining high yields in the last 2 yr. Although late-spring TE applications in flail plots resulted in cumulative yields comparable to those of burn check plots, yields were 34% lower than those of burn, TE spring-treated plots. Fall TE applications had no consistent effect on seed yield. Therefore, neither spring nor fall TE applications are an effective alternative to replace open-field burning in creeping red fescue seed production over the life of the stand if seed yield is to be maximized. Spring TE applications plus open-field burning maximized seed yield and had the greatest harvest index, resulting in a more efficient crop.