Sweet Corn Genotypes versus Ethephon in Relation to Yield Components

Abstract

AbstractOne of the major production related problems associated with sweet corn (Zea mays L. var. rugosa and particularly in the sh2 cultivars, has been root lodging. A study was thus conducted to determine if foliarly applied ethephon [(2‐chloroethyl) phosphonic acid] would effectively reduce susceptibility to root lodging in sweet corn, and to characterize three sweet corn genotypes' responses to ethephon. In 1987 and 1988 the effects of ethephon treatments on plant height, root lodging, and yield were evaluated using three sweet corn genotypes, sugary (su), sugary enhanced (se), and shrunken (sh2). Three cultivars were used within each genotype: Commander, Jubilee, and Stylepak (su); Sentry, Miracle, and Tendertreat (se); and Crisp n Sweet 710, Summer Sweet 8000, and Sweetie (sh2. Ethephon was applied foliarly at 280 g ha−1 at one of two stages of embryonic tassel growth (2.5 ‐ 5.0 or 15.0 ‐ 23.0 cm in length) to each of the sweet corn genotypes and cultivars. Ethephon reduced plant height in both years by 4 to 26%. Root lodging was significantly reduced in Miracle and Tendertreat (se) in 1987 in plants treated with ethephon. Yields were reduced and maturity was delayed in Sentry (se) and Sweetie (sh2) when treated with ethephon. The use of ethephon may be beneficial in cultivars that have a high tendency to lodge. However, during hot, dry years (i.e., 1988), it may be advisable to forego ethephon application on some cultivars.