Shade-induced Modulation of Growth, Yield, and Soil Dynamics in Medicinal Coleus (Coleus forskohlii Briq.)

Abstract

This study evaluated the effects of varying shade levels on the growth, yield, and soil properties of Coleus forskohlii Briq., a medicinal plant of economic and therapeutic importance. The experiment involved three shade treatments: full sun (open), 25% shade, and 50% shade, combined with polythene mulching. Results indicated that shade significantly influenced plant morphology and productivity. Maximum plant height was recorded under 50% shade, while the greatest number of branches per plant occurred in full sun. The highest root yield per plant was observed under 25% shade. Additionally, shade and mulching treatments significantly affected soil properties such as pH, electrical conductivity (EC), moisture content, organic carbon (OC), and microbial activity. Mulched soils, particularly under 50% shade, exhibited enhanced moisture retention, microbial biomass carbon, and enzyme activity. These findings underscore the importance of integrating optimal shade management and mulching practices to enhance the productivity and sustainability of Coleus forskohlii cultivation.