Genotypic variability in seed and seedling growth in Sesbania species

Twenty six genotypes of Sesbania aculeata and Sesbania rostrata were examined for variability in seed characters and seedling growth under field conditions. Though the smaller seeds had faster seedling emergence, the relative growth rate and rate of increase in seedling height was higher for larger and heavier seeds. The larger seeds also showed faster leaf emergence, i.e. lower phyllochron. In contrast to the field germination, all the Sesbania rostrata genotypes failed to imbibe moisture at room temperature indicating physical dormancy due to seed coat impermeability. These seed attributes can be useful in maintaining uniform crop stand (by selection of genotypes and seed treatment) for achieving faster biomass production in Sesbania species for green manuring in rice-wheat cropping system.