A COMPARISON OF ETHEPHON ALONE AND IN COMBINATION WITH CCC OR DPC APPLIED TO SPRING BARLEY

Abstract

Experiments were conducted to determine the relative efficacy of ethephon, alone and in combination with chlormequat chloride (CCC) or mepiquat chloride (DPC), in reducing barley height and lodging in order to protect potential yield. The effects of timing and cultivar of barley were investigated. The results depended on both cultivar and year, indicating that both genetic and environmental factors are important. For Leger barley, application of ethephon between Zadoks Growth Stage (ZGS) 37 and 45 was effective in reducing plant height and lodging; CCC and DPC had no positive or negative effect when added to ethephon. CCC and DPC appeared to enhance the effects of ethephon on lodging control of Micmac barley especially when applied at ZGS 45. Rodeo barley showed the only detrimental effects to grain yield. Ethephon alone applied at ZGS 37 in 1986 caused significant yield loss. CCC or DPC reduced the detrimental effect of the ethephon by acting as apparent antagonists to its effects on this cultivar.Key words: Ethephon, CCC, DPC, lodging, barley