Allelopathic effect of Chromolaena odorata extracts on the growth and development of Celosia argentea

Abstract

Plant species avoiding or excluding other plants species from growing in its environment is likely to contain allelopathic substances that are responsible for the reaction. C.odorata has been observed to possess allelopathic characteristics. Therefore, the allelopathic potentials of chemical substances present in C. odorata was assessed on the growth performances of Celosia argentea in a pot experiment. Plant extracts from Chromolaena odorata were analysed to determine the active chemical ingredients. Results of physicochemical analyses of the soil indicated that it was moderately suitable for agricultural purpose, as all the nutrients needed for proper performance were contained in the soil such as %Nitrogen(20.55), %Organic carbon (18.60), organic matter content  (28.40), p(ug/ g=5.68),pH(6.86), K(mg/100g=1.20), ca and Mn(mg/100g=0.05). chromolaena extracts contained saponins, tannins, alkaloids, frlavonoids and terpenoids as active chemical ingredients. Tannins has the highest mean concentration of 52.6mg/100g  of the extract while flavomoids rercorded the lowest mean concentration of 15.33mg/100g in leaves. There is significant difference atrr p=0.05 in the growth performance of celosia in control and experiments. Ther results are t a 0.05=2.8, 3.0, 1.8, 2.7 and 2.3 for the plant height, stem diameter, mid-rib, number of leaves , and number of branches respectively. Chromolaena extracts boost the performance of Celosia argentea, instead of affecting the growth and performance negatively.