ABSTRACT
Northern N.S.W. hard wheats Kite, Shortim and Songlen, together with the advanced breeding line SUN 44E, have shown consistent differences in their susceptibility to pre-harvest sprouting damage over five years. Kite and SUN 44E are reasonably resistant, Shortim moderately resistant whilst Songlen is normally quite susceptible. In order to define the physiological and biochemical events which are characteristic of the more resistant cultivars, the process of sprouting in response to rain was divided into a number of steps which were then measured independently. Rates of movement of water into grains in intact ears, rates of germination of harvest mature grain and the rates of production of α-amylase all showed significant differences which in conjunction, could account for the observed varietal responses. Changes in germinability during ageing of the grain were responsible for the decline in resistance of all varieties after harvest maturity.
