Physiological maturity in Aestivum wheat: visual determination

Publisher Website
Google Scholar
Abstract
Field experiments were conducted during the winter seasons of 1977–8 and 1978–9 at Agronomy Research Area of Haryana Agricultural University Farm, Hissar, to identify the visual plant characters that coincide with physiological maturity (PM) and 95% maximum grain dry weight (95% MGW) in wheat (Triticum aestivum L.) cultivars. The dry-weight accumulation data from three cultivars (WH-157, HD-2009 and UP-270) differing in many agronomic characters were fitted to polynomial regression equations to calculate time of PM and 95% MGW. The mean number of days from anthesis to 95% MGW and from anthesis to PM ranged from 31 to 36 and 38 to 43, respectively, depending upon cultivar. The time of 95% MGW preceded PM by about 7 days. Of the nine visual plant characters recorded during the grain-filling period, complete loss of green colour from the glumes occurred close to PM. Complete loss of green colour from the flag leaf most consistently coincided with the time of 95% MGW. Complete loss of green colour from the flag leaf could therefore be used as an indicator of the commencement of rapid decrease in grain dry weight and the final stage of grainfilling which ends when the glumes have lost the whole of their green colour.