(L.) Scop maternal effects on seed dormancy under environmental variations imposed by crop canopy

Abstract

Context Different environmental factors occurring during seed development could be responsible for maternal effects on seed dormancy. Understanding these effects on Digitaria sanguinalis (L.) Scop seeds would help to predict it’s seedling emergence. Aims To study D. sanguinalis maternal effects on seed dormancy level under environmental variations imposed by soybean (Glycine max L.) crop, changing (1) nutrient availability, (2) radiation and (3) soybean canopy presence during different phenological stages of the weed. Methods Field plots experiments under semi-controlled conditions were established to reach these objectives. Key results Among different factors evaluated, radiation was the most important factor, mainly during the reproductive stages of the weed. The reduction in solar radiation received by the mother plant diminished seed dormancy level even in those panicles receiving full sunlight in shaded plants. Conclusions Results suggest that solar radiation and temperature operate together in the mother plants to modify seed dormancy level. Implications Crop management decisions such as long crop cycles, late sowing date and narrow inter-row distances would reduce seed dormancy level and would anticipate a concentrated seedling emergence of the weed.