Temperature and Light Requirements for the Sprouting of Chilled and Unchilled Tubers of the Purple Nutsedge, Cyperus rotundus

Abstract

AbstractMature and immature tubers of purple nutsedge (Cyperus rotundus L.) chilled at 0°C in dry and wet conditions, were sprouted along with fresh, unchilled tubers over a range of temperatures (10°C‐45°C) in light and darkness. Fresh immature tubers showed a high sprouting percentage at all temperatures between 20°C and 40°C, while the mature ones did so only at 30°C and 35°C. Chilling of dry tubers stimulated early sprouting and increased the maximum sprouting percentage of both the mature and immature tubers. Dry chilling also lowered the limit of favourable temperatures to 15°C in the case of mature tubers. Chilling of wet tubers had a depressing effect and no sprouting occurred below 30°C.At all temperatures, light apparently favoured the sprouting of both the mature and immature tubers (except mature wet‐chilled ones at 35°C and 40°C). Immature tubers showed relatively higher sprouting percentage than the mature ones, both in light and darkness. Alteration of temperature requirements due to dry and wet chilling of the tubers is regarded as significant and functional in relation to the ecology of the species.