Studies on the Growth and Development of Crotalaria verrucosa L.

Abstract

ABSTRACT Studies were conducted on germination, growth and development of crotalaria (Crotalaria verrucosa L.) because of promising field results on its ability to shade out weeds without adversely affecting yield of associated crops such as maize and cassava. Five different colours of seed coat, namely, yellow, light brown, brown, dark brown and black were found in each of its dry pods that were picked randomly. Seed viability was highest in seeds with yellow seed coat and decreased in the other seed coat colours as follows: yellow > light brown > brown > dark brown > black. Scarified crotalaria seeds showed higher germination than non-scarified seeds. Seed germination was consistently higher among seeds with yellow seed coat than seeds with other seed coat colours irrespective of method of scarification. Mean germination of yellow seeds scarified with water at constant temperatures of 80°C and 60°C was 61% and 51%, respectively, while scarification with sulphuric acid resulted in 45% germination. The best scarification method for yellow seeds was water at 80°C for 30 min. Germination of seeds with other seed coat colours was low and scarification did not significantly improve this. The primary leaf appeared on plants grown from seeds with yellow seed coats earlier than on plants from seeds with light brown and brown seed coats. Similarly, plants grown from seeds with yellow seed coat had higher leaf area index, greater canopy volume, produced more dry matter and more seeds than plants grown from seeds with other coat colours.