Enhancing Wheat Establishment and Yield Using Gibberellic Acid.

Winter wheat producers face a wide range of planting conditions each fall. The benefit of using plant growth regulators to boost wheat establishment and yields has been reported in some areas of the United States. The objective of this research is to evaluate gibberellic acid (GA) for increased establishment and yield in Nebraska’s winter wheat crop. Three wheat varieties were planted at three locations in western Nebraska at 3.75 and 7.5 cm depths. The study design was a split-plot design where the whole-plot factor was seeding depth and the split-plot factor was wheat variety with GA treatment. The varieties used were Husker Genetics Wesley, Camelot, and Goodstreak Brand winter wheat which have short, medium, and long coleoptiles, respectively. GA was applied as either a seed treatment, or a fall or spring applied foliar spray. Wheat stand were recorded in the fall. NDVI was recorded at boot stage and plant height, and number of tillers per row foot were recorded prior to harvest. Plots were harvested with a plot combine and wheat yield, test weight, and moisture were recorded. When combined across all treatments, planting at 7.5 cm resulted in yields 10.6% greater than shallow planted seed. Fall applied GA increased wheat yields 8.5% over the untreated. Adequate planting depth and fall applied foliar GA can both be used to maximize wheat yields.