Prohexadione-Calcium Reduces Height and Lodging of Winter Wheat.

Shortening stem length of winter wheat (Triticum aestivum L.) would improve production under intensive management. The objective of a three-season study (2006-2009) was to reduce height and prevent lodging of winter wheat using two growth inhibitors. Prohexadione-Ca is an anti-gibberellin that inhibit cell elongation, and ethephon releases ethylene that inhibit cell growth. At labeled rates, prohexadione and ethephon were applied in the spring around the flag-leaf stage to six cultivars of winter wheat. Averaged over trials and cultivars, plant height reduction by prohexadione was 21% at the high label rate, and for ethephon, it was 8%. In 2008, lodging occurred in cvs. Alliance, Buckskin, Goodstreak, Millennium, and Jagalene, but not with Wesley. Lodging was reduced to near zero by all treatments. However, prohexadione was more effective than ethephon. In 2007 and 2008, grain yields were increased 15% and 30% by the high rate of prohexadione, respectively, and for ethephon, it was 11% and 23% for the two seasons, respectively. No treatment affected grain viability. Prohexadione-Ca was a better alternative to ethephon for reducing plant height, reducing lodging under intense management conditions, and promoting yield of winter wheat.