The effect of sesbanimide and Sesbania seed extracts on germination and seedling growth of a number of plant species

Abstract

Sesbanimide and extracts made from ground powders of whole Sesbania punicea and S. bispinosa seeds and isolated embryos and testae of S. punicea inhibited the germination of vegetable, grass and weed seeds. This inhibition was more noticeable on seedling growth than on germination. The inhibitory effect was not transitory but was manifested even after transplanting the seedlings. In all cases, the roots were more sensitive than the shoots and their growth was severely retarded. The inhibitory effect was also detected if the test seeds were soaked in extracts prior to sowing. Embryo and testa extracts of S. punicea gave an inhibitory response. The former was the most inhibitory. This inhibition may partly explain why S. punicea forms dense, uniform stands when invading natural vegetation. There appears to be a strong allelopathic effect expressed by the seed extracts. This warrants further investigation.