Abstract
To ascertain the effects of difference of paddy field management from winter-spring on the fate of Aeschynomene indica L. seeds, we investigated the dormancy of seeds that wintered in paddy fields at different depths and under different ground cover conditions and the germination of those seeds in the summer as they floated on the surface of water. From winter to mid-late May, seeds buried at a depth of 10cm in autumn did not break dormancy for the most part, regardless of the surface conditions, while seeds on the soil surface did break dormancy. However, ground cover with winter vegetation or rice straw delayed the breaking of dormancy by seeds on the soil surface. In mid-late May, >50% of the seeds that wintered under straw cover were dormant while >95% seeds on a bare soil surface broke dormancy. More than 80% of the seeds that wintered on a bare soil surface germinated within 5 days of being floated on the surface of water in mid-May, and none of seeds survived to early July. Only a few of the seeds that wintered under soil or straw cover germinated while floating on the surface of water, and >50% of the seeds remained dormant and survived to early July. These results suggest that most of the seeds dispersed in autumn will break dormancy from winter-spring in fallow/untilled fields and that most of these will be lost due to germination during rice cultivation.
