Post‐Anthesis Ethephon Effects on Yield of Spring Barley

Abstract

AbstractEthephon (2‐chloroethyl phosphonic acid) application after heading may enhance the grain yield of cereal crops such as barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) by altering grain‐filling processes. The objective of this study was to evaluate the effects of post‐anthesis (1 wk after heading) ethephon application on variables contributing to the grain yield of spring barley cultivars. A field experiment, with application of ethephon at three rates (0, 240, and 480 g a.i. ha−1) to two barley cultivars, Cadette and Leger, was conducted on Bearbrook clay soil (fine, mixed nonacid, mesic Humaquept) in Quebec, Canada in 1988, 1989, 1990. A post‐anthesis application of ethephon extended the grain‐filling period by 1 to 3 d with variation among both cultivars and years. The 1000‐grain weight of both cultivars significantly increased in all 3 years while no changes were found in the other yield components (spikes per square meter and grains per spike). Grain yield of Leger (conventional stature) was increased 5 to 12% more than unsprayed controls while Cadette (semidwarf) grain yield was either not altered or significantly reduced. These results indicate that under climatic conditions such as those prevalent in northeastern North America post‐anthesis application of ethephon can potentially enhance grain fill and yield of spring barley.