Allelopathic Effects of Aqueous Rhizome Extract of <i>Kaempferia galanga</i> on the Growth of Red Chilli (<i>Capsicum annuum</i>)

Abstract

Kaempferia galanga L showed an allelopathic clues when intercropping planted with coconut plants, however aspects related to allelochemicals of this plant and their inhibitory or stimulatory properties against other crop plants has not been investigated in earnest. This research was conducted in order to determine whether the crude extracts of kacholam have allelopathic properties, either negative or positive, against red chilies. By using completely randomized design, 25 chilli plantss were grouped into five consist of 5 plants each. Each plant was grown individually in a poly bag containing mixture of soil and compost in a ratio of 2:1. Group 1 is the chillies given 0% (v/v) kacholam extract as the control. Group 2, 3, 4 and 5 are the plants treated with kacholam rhizome extract at a concentration of 25%, 50%, 75% and 100% respectively. After being treated for one week the chillies are harvested and all the study parameters namely plant height, dry weight, and concentration of chlorophyll were assessed. The results showed, plant height of red chillies significantly suppressed by kacholam rhizome extract with a concentration of 50% or higher. The dry weight of red chillies was significantly decreased by treatment of kacholam rhizome extract in all level of concentration. However, crude water extract of kacholam plant rhizome showed no significant effects on the concentration of chlorophyll a as well as chlorophyll b. In conclusion, the crude extract kacholam plant rhizomes contains suppressive allelochemicals and, thus Kaempferia galanga is potential to be used as a negative, instead of positive, allelopathic crops.