Growth and development of Xanthosoma and Colocasia under different light and water supply conditions

Abstract

Barbados nut eddoe ( Xanthosoma saggittifolium) and Trinidad eddoe ( Colocasia esculenta var. antiquorum), both producing cormels, were tested in a pot trial for tolerance to shade and water stress. Barbados nut eddoe produced the highest dry matter yield under shade and full water supply by developing long petioles and large leaf blades. Under shade and water stress only the corm grew and the growth of cormels was negligible. As a result of the increased development of above-ground plant organs, the plant was able to survive stress conditions but with a low yield of edible organ material. Trinidad eddoe produced the highest dry matter yield with full light and adequate water supply. These conditions permitted a rapid growth of the corm and stimulated the development of cormels so that cormel yield was twice that of the corm. The rate of leaf production declined steadily and the plant “matured” after about 5 months. Stress conditions such as shade or lack of water led to slow growth and retarded development of cormels; cormel yield was only about half that of the corm. A combination of these stress conditions caused the plant to almost die. The physiological aspects of the different reactions of the species are discussed.