Height and Yield Response of Selected Wheat, Barley, and Triticale Cultivars to Ethephon1
- K. Dahnous,
- G. T. Vigue,
- A. G. Law,
- C. F. Konzak and
- D. G. Miller2
Yield losses occur in cereals as a result of lodging. Ethephon [(2-chloroethyl)phosphonic acid] has been reported to reduce lodging; however, studies of its effect on grain yield have produced conflicting results. In this study. selected cultivars of semidwarf wheat (Triticum aestivum L.), normal height barley (Hordeum vulgare L.) and triticale (Triticale hexaploid L.) were treated with ethephon to determine (1) if this growth regulator had an effect on yield other than via a reduction in lodging and (2) the optimum growth stage and rate (kg/ha) of application. Foliar-applications to field grown plants (the soil was a fine-silty, mixed, mesic Cumulic Haplaxeroll) were made at two plant growth stages, late boot and early heading. Ethephon was applied at 0, 0.28, and 0.55 k&a in 1976 and at 0, 0.28, 0.55, and 0.85 kgha in 1977. Main plots were fertilized with 45 or 90 kg N/ha in 1976 and 90 or 180 kg N/ha in 1977.
Ethephon applications at the late boot stage reduced the elongation of plants more effectively than applications at early heading. Ethephon treatments reduced elongation of tall cereal species, i.e., barley and triticale were significantly shorter following treatment of 0.28 kg/ha in 1977. Ethephon treatments increased harvestable yields when they reduced lodging. For instance, untreated ‘Unitan’ barley lodged heavily, but ethephon treatment of 0.55 kgha reduced lodging which resulted in increased harvestable yields. Ethephon treatment of 0.84 kg/ha significantly inhibited stem elongation in semidwarf wheats, but semidwarf wheats did not lodge and treatment did not increase yields. The results of this study indicate that further field testing should be conducted in regard to ethephon's potential to benefit yields of tall, ‘weak-stemmed’ cereals such as barley, since no benefit was derived from ethephon treatment to semidwarf wheats.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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