Plant Morphology of Cassava During Summer and Winter

The information on developmental changes in cassava (Manihot esculenta Crantz) in response to environment is often lacking despite interest in such work. This study was conducted to examine how patterns of leaf area development, plant growth, and root production were influenced by seasonal changes in temperature. A field experiment was established during summer 1986 and winter 1987 on the island of Oahu, HI. The growth and yield of the cultivar Ceiba was contrasted across seasons. During a 120‐d period, mean air temperature during summer and winter were 27.0 and 22.5 °C, respectively. Stem numbers per plant did not differ significantly from summer to winter but plants were taller, internodes were longer, branches per stem were greater, and leaf numbers were higher for plants grown during summer. Also, the number and fresh weight of marketable roots (diameter>5 cm) were greater for plants grown during summer. These differences in response between summer and winter crops suggest that plant growth and root yield production of cassava in Hawaii were more efficient during the summer months. Data from this study will be used to validate a cassava growth model being developed for use in agrotechnology transfer in the tropics.