The effects of leaf harvesting and spacing on the yield of xanthosoma and colocasia spp

Abstract

From the sixth leaf stage onwards, three leaf harvesting treatments were imposed on Xanthosoma sagittifolium and Colocasia esculenta planted in separate experiments at 1 x 1m (S1). 1 x 0.75m (S2) and 1 x 0.50m (S3). The defoliation treatments consisted of a control (no leaf harvest), alternate defoliation (harvesting of every other new leaf), and complete defoliation (harvesting of all new leaves I. In Xanthosoma, leaf harvesting resulted in significant reduction in cormel yield. The reductions from the control were 31.4% and 58.6% for alternate and complete defoliation respectively. Apart from number of cormel per plant which showed a similar trend, the other parameters, corm yield, corm size and cormel size showed no significant differences. In Colocasia, leaf harvesting had ho significant effect on corm yield. Corm size and number of suckers were significantly affected, but there was no clear trend. Cormel yield was significantly higher at the narrowest spacing in Xanthosoma. Yield increases over S1 were 18.2% and 59.6% for 52 and S3 respectively. Spacing had no significant effect on number of cormels per plant, corm yield and size of corm, but cormel size was significantly reduced at the narrowest spacing in Xanthosoma. In Colocasia, spacing had no significant effect on corm yield, but there was a 30.1% reduction at the narrowest spacing compared to the widest spacing.