Ethephon Influence on Harvestable Yield, Grain Quality, and Lodging of Corn

Abstract

AbstractTo determine if ethephon ((2‐chloroethylphosphonic acid) would reduce lodging while maintaining or increasing harvestable yield, the influence of timing and rate of ethephon application on harvestable yield, yield components, lodging, and grain quality of corn (Zea mays L.) was studied in 1985 and 1986. Ethephon was applied at rates of 0, 0.14, 0.28, and 0.56 kg ha−1 at tassel elongation (TE), 6 d after tassel elongation (TE+6), and at ear elongation (EE), to Pioneer hybrids P3475, P3377, and P3183 grown in the field near Mead, NE. Application of ethephon reduced lodging of corn plants. Ethephon application of 0.56 kg ha−1 at the EE stage reduced lodging of P3377 and P3183 from 30 to 9%. This rate resulted in production of 52 fewer kernels per ear, and 7 to 17 mg lighter kernel weight, while increasing the number of harvestable ears by 0.2 to 0.6 ears m−2. Increasing the rate of ethephon resulted in a linear decrease in harvestable grain yield, except when applied at the EE stage in 1986, when ethephon application had no influence. In this case, increasing the rate of ethephon resulted in an increased number of harvestable ears per square meter, which compensated for reductions in the number of kernels per ear and kernel weight. Application of 0.56 kg ha−1 ethephon at TE in 1986, TE+6 in both years, and EE in 1985 resulted in approximately 1 Mg ha−1 reduction in harvestable grain yield. Ethephon application had small but significant influence on the protein content, kernel density, and kernel breakage susceptibility of grain produced. Application of ethephon is effective in reducing lodging of corn plants. However, ethephon never increased and usually reduced harvestable grain yields. Based on these results, there is little incentive for producers to consider application of ethephon to corn grown under conditions similar to those in this study.