Temperature and heterogeneity of emergence time in oilseed rape

摘要: SUMMARY Emergence of oilseed rape cultivars with known differences in germination profile was examined by controlled sowings the field at mean temperatures between 2 and 10°C. Early percentiles, up to 50th two (Rocket Martina) 20th a third (Comet), responded temperature similarly all sowings, that 1/time emergence percentile (emergence rate) increased exponentially above an intercept of-1°C. For these occurred similar thermally weighted time over whole range temperature, indicating peak first flush seedlings is predictable. Percentiles higher than those cited displayed increasing non-germination (probably secondary dormancy) as declined towards winter. The maximum ranged 50% 80% among cultivars. In during just after winter, rate percentiles lower comparable before A portion non-germinating seeds most heterogeneous overwintered emerged synchronously April from pre- post-winter probably stimulated diurnal amplitude 7 15K. At low therefore, exhibited great heterogeneity profile, more being likely give rise temporally separate weed or feral populations. findings are discussed context weediness transgene movement metapopulation.