Studies on the Effect of Plant Density on Plant Height and Number of Laterals of Medicinal Coleus [Coleus forskohlii (willd) Briq.]

Closer spacing (60 cm*20 cm) resulted into tallest plants compared to 60 cm*45 cm and 60 cm*30 cm during all growth stages, may be due to accommodation of more number of plants per unit area which might have created competition for water, nutrients, and sunlight might have caused the plants to grow vertically. Since the auxins are less prone to photo-oxidation and destruction under low light conditions, promoted the production of taller plants. Plant height increased significantly with decrease in plant density could be due to photomorphogenic response. Wider spacing (60 x 45 cm) resulted in production of maximum number of laterals per plant (18.40) compared to 60 x 30 cm (16.71) and 60 x 20 cm (16.00). This might be due to better light penetration results in more photosynthesis and more number of laterals. Less plant population resulting in reduced competition for space and other resources like water, nutrients, and sunlight might have also caused more number of laterals.