Dry heat scarification of Stylosanthes guianensis seed

Abstract

Exposure of seeds of the four main varieties of Stylosanthes guianensis (cvv. Schofield, Cook, Endeavour and Oxley) to dry heat of 50°, 60°, 70° or 80°C for 6 h reduced the level of hardseededness by varying extents depending upon the cultivar, the temperature and the particular sample. None of the heat treatments affected viability and thus a decrease in hardseededness was associated with a corresponding rise in the level of germination. Seed lots of Schofield, Cook and Endeavour may be scarified using dry heat (80°C for 6 h) when rapid germination is of paramount importance. The same heat treatment could be used for cv. Oxley (even though it is less effective) because of the characteristically low germination of untreated seed of this cultivar.