EXPLORING THE BIOSTIMULANT POTENTIAL OF COMPOST TEAS FOR SUSTAINABLE ONION PRODUCTION

Abstract

This study evaluated the biostimulant potential of compost teas derived from various organic materials on the physiology of onion (Allium cepa L.) and soil health attributes under field conditions at the Islamia University of Bahawalpur. Three types of compost teas—vermicompost tea, farmyard manure (FYM) tea, and poultry manure tea—were prepared and applied as foliar sprays at critical growth stages. Parameters i.e., plant height, bulb diameter, bulb fresh weight, number of leaves, chlorophyll content, and stomatal conductance were assessed along with post-harvest soil properties including pH, electrical conductivity (ECe), organic matter, and microbial biomass carbon. Results revealed that all compost teas significantly enhanced onion growth and bulb yield compared to the control, with vermicompost tea exhibiting the most pronounced effects. Vermicompost tea-treated plants achieved the highest bulb weight (182.3 g), leaf chlorophyll content (56.4 SPAD), and soil organic matter (1.25%), indicating improved nutrient availability and microbial activity. The findings suggest that compost teas, particularly vermicompost tea, can serve as sustainable, eco-friendly biostimulants, improving onion productivity while maintaining soil health. These results support the integration of compost teas into organic and low-input agricultural systems.