Nutrient uptake analysis of black cohosh (Actaea racemosa L.) grown under shade in greenhouse

Abstract

This research was determining optimal fertilizing strategies for Black cohosh, as an herbal alternative for menopause, to increase crop productivity. Nutrient uptake was analyzed on one-year old plants grown under 80% shade in a greenhouse and exposed to two nutrient application treatments: single and continuous exposures of fertilizer at 0%, 2%, 4%, 6%, 8% and 10% concentrations during a one-year study. Two respective experimental designs were used for growth data and nutrient uptake analysis. Growth data was using a Completely Randomized Split Plot Design, with two treatment groups, single exposure and continuous exposures of fertilizer, and six subplots for each concentration. Nutrient uptake analysis was using a Completely Randomized Design and conducted only on single exposure fertilizer treatment for total amount of calcium, iron, potassium, magnesium, manganese and zinc. Single exposure (5 replications) of fertilizer had one application of fertilizer solution per concentration, to soil, one week before planting, while continuous exposure (7 replications) of fertilizer had an initial application of fertilizer solution one week before planting and subsequent application of fertilizer solution per concentration, once a week for entire growing season. Continuous exposure led to a significant decrease in growth and rhizome weights, and a significant increase in stem number per plant as fertilizer concentration increased. No growth change was observed with a single exposure of fertilizer, except for a decrease in stem length. Black cohosh mainly utilizes calcium, potassium, magnesium and zinc as it fully matured, and manganese since initial growing stage. Calcium and magnesium accumulated primarily in leaves, while potassium accumulated in stem and iron in rhizome