SEED PARTITIONING AND YIELD RESPONSES TO TRINEXAPAC-ETHYL IN PERENNIAL RYEGRASS

T.G. Chastain, W.C. Young III, C.J. Garbacik & T.B. Silberstein
Crop Science Bldg. 107, Dept. of Crop and Soil Science, Oregon State University, Corvallis, Oregon, 97330, USA

Trinexapac-ethyl (TE) plant growth regulatory impacts on seed partitioning and yield were examined in field trials over a 3-year period in perennial ryegrass (Lolium perenne L.). Seed yield was consistently increased by TE in each year, but seed yield declined as the stand aged regardless of treatment. TE-induced increases in seed yield resulted from improvements in floret production and seed set. TE increased seed number but had no effect on seed weight, seed germination, or subsequent seedling weight.