Effect of population density on growth performance of Andrographis paniculata and Centella asiatica

Abstract

The present paper deals with the effect of population density on growth responses of Centella asiatica (L.) Urban and Andrographis paniculata (Burm f.) Wall. ex Nees. The pot culture experiment was conducted for 4 months and treatment consisted of four levels of plant density, viz., D1, D3, D6 and D9 with respectively, 1, 3, 6 and 9 plants per pot. These densities are approximately equivalent to 23, 69, 140 and 209 plants per m2. Plants were harvested at the end of the experiment. Several growth variables, viz. leaf area, total biomass, Root:Shoot ratio, relative growth rate, net assimilation rate, vegetative growth and sexual growth were determined. Both species were able to modify reproductive responses, allowing them to grow with increased density. The biomass, relative growth rate and net assimilation rate of individual plant decreased with increasing density, and the decrease was much pronounced for A. paniculata than C. asiatica. The biomass of C. asiatica increased significantly up to D6, and the increase was not significant for A. paniculata. Thus, on population level, C. asiatica responded better to increasing plant density than A. paniculata in terms of growth.