THE ROLE OF NATURAL AGENTS IN THE REMOVAL OF COAT-IMPOSED DORMANCY INDICROSTACHYS CINEREA (L) WIGHT ET ARN SEEDS

Dichrostachys cinerea seeds are impermeable to water and do not germin ate readily. The plant, however, contributes to a bush encroachment pr oblem, minimising visibility in wildlife reserves and reducing the are a available for grazing. Natural dormancy-breaking conditions must the refore exist, promoting the germinability of these normally dormant se eds. Diurnal temperature fluctuations (50 degrees C/15 degrees C), esp ecially when combined with moisture were found to break dormancy. High temperatures, such as those generated by fire, destroyed seeds. Seeds ingested by herbivorous browsers such as nyala, became permeable. See d burial for 48 weeks, was a more effective treatment than storage in promoting permeability. Distribution of D. cinerea will therefore be r estricted to areas in which these conditions or factors occur. Seeds g erminated optimally at 30 degrees C in the laboratory.