Large Headsetts and Improved Cultivar Enhance Growth and Development of Taro (Colocasia esculents [L.] Schott) During Establishment

Small, medium and large headsetts of a traditional ( Nine ) and an improved ( Alafua Sunrise ) cultivar of taro were grown for 33 days in pots in a screenhouse.
Differences between the cultivars were greatest in root growth where density of root primordia, number of primary roots and root surface area at the final harvest were 53, 82, and 60 % greater respectively in the improved over the traditional variety. Relative rate of leaf elongation and leaf appearance rate were about 30 % faster in the improved variety. Correlation between leaf area and root surface area was cultivar dependent.
Large headsetts produced more primary roots and a larger root surface area than small headsetts. They also produced 46 % more leaf area than small headsetts because of larger individual leaves, but not the rate of leaf appearance.
Dry matter and nitrogen content declined in petioles, remained relatively constant in corm and accumulated in new shoot and root during establishment. Losses of N were similar but accumulation was greater in new growth of Alafua Sunrise than Niue.
We conclude that differences in productivity between the improved and traditional cultivars used in this experiment are at least partly attributable to differences in rate of development of new shoot and root during establishment. Previously reported correlations between corm yield and size of planting material are probably due to large headsetts producing a greater area of leaf and root than small headsetts during early growth.