Vermicompost as a component in potting mixes for growth promotion in ornamental plants

Abstract

Vermicomposts are very important in crop production as they contain biologically active substances such as plant growth regulators. Two experiments were carried out at Wageningen University in 2007 to determine the effectiveness of vermicompost in uptake of nutrients by plants. In the first experiment, seeds of water-cress (Lepidium sativum L.) and lettuce (Lactuca sativa L.) were germinated using different
concentrations of Indole Acetic Acid and Gibberellic Acid then, extracts of vermicompost, green waste compost, and course peat with different dilutions. In the second experiment, root initiation in mungbean cuttings was assessed at different
concentrations of Indole Acetic Acid and different dilutions of the compost extracts. Increased concentrations of Indole Acetic Acid depressed root growth in watercress and mungbean, whereas increased Gibberellic Acid concentrations promoted shoot growth in lettuce. Compost extracts positively? influenced root and shoot growth in the three plant species especially without any dilution. In lettuce shoot and root length
increased with decrease in dilutions of compost extracts; in watercress, root length increased more than shoot length in all dilutions; while root initiation in mungbean increased with increase in dilutions apart from peat extract. Peat extract was most effective on root initiation in mungbean while ermicompost was most effective in both lettuce and watercress root/shoot length formation. Results from this study suggest that vermicompost, green waste compost and peat may contain plant growth regulators. The effects of compost extracts on plant growth and development were attributed to plant growth hormones produced by microbial activity during compost and peat formation.