Effect of temperature and depth of burial on the persistence of seed of Avena fatua L. in Western Australia.
Abstract
Constant temperatures within the range 11-23 C had no significant effect upon the germination of Avena fatua, but higher temperatures appreciably reduced germination. Fluctuating temperatures reduced germination if one of the temperatures was greater than 23 C. Over 90% of the initial seed population emerged over three years from depths between 2.5 and 12.5 cm but less than 65% emerged from greater depths. Only 3% of remaining seed survived at 2.5 cm and deeper depths but at 0.5 cm 9% survived. The difference was probably due to drier conditions near the soil surface. It is suggested that infestations of A.fatua could be economically reduced by a three-year pasture phase, with grazing to prevent seed production.