ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 56 Number 1
Effect of daylength and gibberellic acid on the growth and promotion of flowering in tannia (Xanthosoma sagittifolium)
The effects of daylength and GA3 on the growth and promotion of flowering in tannia were studied. Under short days petiole extension was retarded but storage organ dry weight was increased in plants given short days immediately after planting. This increase resulted from a stimulation of cormel initiation which seems to occur within two months after planting and which also appears to be affected by temperature. Daylength had no discernible effect on the number of leaves per plant, leaf size, or total leaf area. GA3 treatment retarded the rate of leaf production initially but later increased leaf number by pro-moting the development of axillary leaf systems, and had little effect on petiole extension or leaf expansion. GA3 treatment, irrespective of daylength, reduced storage organ dry weight by reducing corm and cormel bulking but had little effect on cormel initiation. The results indicate that the tannia has no obligate daylength requirement for flowering.