Effect of growth retardants on growth, flowering, vase-life and tuber formation of dahlia (Dahlia Variabilis Desf.) propagated through cuttings

Abstract

A field experiment was conducted at the college of Agriculture, Vellayani during 1990-91 to study the effect of growth retardants on growth, flowring, vase-life and tuber formation of Dahlia (Dahlia variabilis Desf.) propagated through cuttings. Among the chemicals tried Alar markedly retarded the plant height and at the same time significant increase in the number of branches and leaves compared to control and the effect of CCC was not much pronounced. Treatment with Alar and CCC markedly increased the size of leaves compared to control. Chemical CCC was superior to alar with respect to total chlorophyll content. There exists a highly significant increase in internodal length at the highest doses of CCC against its control except at 75th day. Compared to Alar, the plants treated with CCC show a highly significant increase in thickness at node and internode. Treatment with Alar delayed flower bud appearance by 3.9 to 5.9 days while CCC induced earliness in flowering by 8 to 10 days. However there was no significant difference between the chemicals for the number of flowers. Treatment with Alar also improved the size of the flower, increased the number of florets and the flower remained fresh for a longer period on stalk and in vase. Those plants treated with Alar showed an increase in the weight of tuberousroot and maximum tuber production was noticed with Alar 4000ppm.