Mechanical scarification of Stylosanthes guianensis cv. Oxley seed.

Abstract

In a series of experiments, in-pod seed of Stylosanthes guianensis cv. Oxley from various sources, containing high proportions of hard seed, was mechanically scarified either by abrasion or impact treatments, involving different machine speeds and numbers of passes through the machinery. The effects on the resultant proportions of naked seed, in-pod seed and waste, as well as germination capacity were estimated. Combine harvested seed had higher initial germination percentage than seed harvested with a smaller suction harvester, and needed less scarification to attain a given germination capacity. Modification of a commercial scarifying machine by replacing the carborundum lining with rubber, satisfactory increased germination capacity, and little seed was damaged with the correct procedure. A hammer-mill operation at reduced speed damaged the seed without effective scarification. The experiments provided a guide to the optimum number of passes for various machines.

Keywords: germination; procedure; scarification; seed; stylosanthes guianensis; treatment; treatments