Hypoxis hemerocallidea cormlet production in response to corm cutting and exogenous application of plant growth regulators

Abstract

The study was undertaken to understand the effect of plant growth regulators (PGRs) on cormlet production in Hypoxis hemerocallidea corm cuttings. In the first experiment, conducted in spring and summer, whole corms and corms subjected to chipping into four or eight segments or to scooping were used. These were soaked in 1.0 g L^− 1 indole-3-butyric acid (IBA), 0.5 g L^− 1 α-naphthalene acetic acid (NAA), a combination of 1.0 g L^− 1 IBA and 0.5 g L^− 1 NAA, or distilled water (control) for 16 h. In the second experiment, corms cut by chipping into eight segments were soaked in 25, 50, or 100 mg L^− 1 of 6-benzyladenine (BA) or gibberellic acid (GA₃), as well as their combinations (100 mg L^− 1 GA₃ + 25 mg L^− 1 BA, 100 mg L^− 1 BA + 25 mg L^− 1 GA₃) for either 30, 60, or 120 min. Soaking corm cuttings chipped into equal segments in distilled water significantly increased the number of cormlets compared to soaking in IBA or NAA. Chipping into eight segments and soaking in distilled water resulted in a significantly higher number of cormlets in the summer experiment. There were no significant differences in the number of cormlets when the eight segments of corm cuttings were soaked in BA and GA₃. Soaking the corm cuttings for 120 min in GA₃ at 25 mg L^− 1 resulted in all eight segments of the cuttings producing one cormlet each. This is the first report on vegetative propagation of H. hemerocallidea showing that PGRs' had no positive effect on cormlet production.