SEED DORMANCY IN DORMOATS: WINTER SURVIVAL AND SPRING EMERGENCE

Abstract

Dormoats are derivatives of hybrids between Avena sativa L. and A. fatua L. designed to be sown in autumn to germinate the following spring. Information was needed on the fate of field-planted dormoats throughout the seasons, in order to gain insight into the mechanism(s) contributing to spring emergence. Seeds from three dormoats (PGR8658, PGR16727 and PGR16728) showing variability in depth of dormancy were each sown in fiberglass mesh bags, in the field in late summer. Germination behavior, in field emergence and laboratory tests, after burial of the seeds outdoors for various periods showed that different survival mechanisms were present in dormoats and that dormancy types and levels could fluctuate. Seeds entered, left and re-entered the dormant condition throughout the seasons. These germination behaviors are typical of weeds and the spring emergence levels achieved by dormoats are similar to those of wild oat. It seems that this facet of the expression of the wild oat dormancy trait has not been modified despite the numerous breeding strategies used for dormoats. New approaches have to be sought to achieve good spring emergence of this experimental crop.Key words: Dormancy, dormoats, emergence