Time of Physiological Maturity and Post‐Physiological Maturity Drying Rates in Wheat1

Abstract

Field experiments were conducted in 1978 through 1981 to determine kernel moisture at physiological maturity and to study post‐physiological maturity drying rates in spring wheat (Triticum aestivum L.). Time of physiological maturity was taken as the date beyond which there was no significant increase in kernel dry weight. Yearly environmental conditions influenced kernel moisture at physiological maturity. Under low rainfall conditions, physiological maturity occurred at higher kernel moisture values than under wet conditions. Physiological maturity was probably induced prematurely by drought conditions. Cultivar ranking for kernel moisture at physiological maturity was reasonably consistent from year to year. Over cultivars and years, physiological maturity occurred at 32.4 to 43.6% kernel moisture. There was little difference among cultivars in rate of water loss after physiological maturity. Comparisons of drying rates are difficult in materials that reach physiological maturity on differing dates. Environmental conditions favoring rapid drying may have masked genotypic differences in drying rate.