ABSTRACT
The propensity of some wheat varieties to have unacceptably high levels of α-amylase at maturity even in the absence of visible sprouting has been recognised for some years. This chapter describes experiments designed to ascertain how important prematurity production is as a component of harvest α-amylase levels. Clearly α-amylase production before maturity may be a general phenomenon which appears to be enhanced under slow grain drying conditions. In addition, the occurrence of limited detached grain germinability and aleurone gibberellic acid (GA) responsiveness during approximately the same period confirms that the enzyme production is related to grain mobilization processes. The separate measurements of embryo germinability and distal half grain responsiveness to GA showed that a short period of limited whole grain germinability coincided with a similar ‘window’ of aleurone responsiveness. Several varieties were sampled at weekly intervals for enzyme content, germinability and aleurone GA-sensitivity and harvest was delayed to increase the chance of observing visible sprouting damage.
