Seed ripening in grasses. I. Changes in carbohydrate content

Abstract

1. In grass seed crops accurate assessment of the optimum harvest date is made difficult by the lack of knowledge of seed ripeness. In order to define ripeness in physiological terms studies have been initiated the first of which is described in this paper.2. Samples of Aberystwyth S. 321 perennial ryegrass (Lolium perenneL.), S. 143 cocksfoot (Dactylis glomerataL.), S. 48 and S. 352 timothy varieties (Phleum pratense L.) were taken at 3-day intervals from inflorescence emergence to seed harvest. These were analysed for total 80 % ethanol soluble carbohydrates (TSC) reducing sugars, sucrose and starch, whilst duplicate samples were air-dried for determination of thousand seed weight and percentage germination.