The influence of nutrient availability on the growth and morphology of Chromolaena odorata (siam weed)

Abstract

Invasion success is more often influenced by the nutrient availability in the ecosystems. The growth and morphological responses of the invasive plant species, Chromolaena odorata (Siam weed; Asteraceae) was evaluated in three different nutrient conditions. The experimental conditions were addition of 1g (High) and 0.25g (Medium) of 20:20:20 N: P: K mixture per pot, once in a week and natural soil as the control without adding any nutrients. The experiment continued for 100 days with 6 replicates. Statistical analysis was done by using one way ANOVA method. At the end of the experiment period, high nutrient condition significantly (P>0.05) increased the biomass content of the plant (shoot and root dry mass, relative growth rate, specific root length). High nutrient treatment increased relative growth rate more than 73% compared to the control. In general, nutrient addition significantly increased the biomass content of a plant. We hypothesize that invasion and domination of C. odorata can be suppressed by minimizing nutrients accumulation in invaded ecosystem as one control mechanism.