Exogenously applied gibberellic acid affects shoot regeneration, growth, physiological parameters, and proximate and mineral contents of pot-grown Solanecio biafrae

Abstract

ABSTRACTSolanecio biafrae (Oliv.& Hiеrn) C. Jеffrеу iѕ a trаditiоnаl leafy vеgеtаblе in Afriса, but its vegetative growth is slow, making production fall short of market demands. Gibberellic acid (GA3) is a hormone produced by plants that stimulates growth and enhances absorption of minerals. However, GA3 synthesis is limited in shoots of S. biafrae due to inadequate external stimuli. To increase yield of S. biafrae and its proximate and mineral contents, external application of GA3 is desirable to supplement internally produced GA3. This study examined the influence of exogenously applied GA3 on shoot emergence, growth, fresh shoot weight, physiological parameters, proximate, and leaf mineral element contents of the green-stemmed morphotype of S. biafrae. Stem-cuttings were treated at 1, 3, аnd 6 dауѕ after planting with 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 mg∙L−1 of GA3 in plastic pots. Exogenously applied GA3 influenced most parameters measured except leaf K. Total number of leaves, total leaf area, fresh shoot weight, dry weight, carotenoids, phenolics, total soluble sugars, ash, carbohydrates, leaf Na, P, Mg, Ca, Fe, and Zn increased as GA3 concentration increased up to 80 mg∙L−1. Number of days to shoot emergence and crude fat content were lower in treated plants than controls. Chlorophyll a was highest at 60 mg∙L−1. The study concluded that the optimum GA3 concentration was 80 mg∙L−1 as it promoted the highest total number of leaves, total leaf area, shoot height, dry and fresh shoot weights, and produced the highest synthesis of chlorophyll a, phenolics, total soluble sugars and proteins, crude fiber, protein, ash, carbohydrates, leaf Na, P, Mg, Ca, Fe, and Zn.