Allelopathy of Native Plant Species

allelochemicals. One of them is the Eucalyptus deglupta, which is unique among eucalyptus. Unlike other members of the genus, rainbow eucalyptus hails from the Philippine Islands; specifically, the island of Mindanao, which is why the tree is also referred to as a Mindanao gum. According to the study of Bughio, Mangrio, Abro, Jahangir and Bux, it has been found that Eucalyptus species release volatile compounds such as benzoic, cinnamic and phenolic acids which inhibit growth of crops and weeds growing near it. Phenolic acids and volatile oils released from the leaves, bark, and roots of certain Eucalyptus spp. have deleterious effects on other plant species. In the study of Bughio et al., using the eucalyptus camaldunlensis as allelopathy agent against Acasia nilotica, The Eucalyptus leaf litter and leaf litter extract also caused significant reduction in seedling vigour index of Acacia nilotica. Based on the results of their study it is concluded that allelopathy is a concentration-dependent phenomenon, as the concentration of the E. camaldulensis treatments increases, its effect increases. The leaf litter and leaf litter extract affected all the parameters as compared to the control. Based on the study of Anwar, Eucalyptus has been known to be able to excrete a substance harmful called allelopathy, to other vegetation. To encourage the establishment of timber estate, it is necessary to examine the effects of allelopathy on other plants, whenever mixed plantation is carried out. Three kind of plant portion (fresh leaf, leaf litter and root) from two Eucalyptus species (Eucalyptus alba and E. deglupta) which are suspected to have allelopathy and five extract concentrations (0%, 5%, 10%, 15% and 20%) were used as treatment for the growth of Shorea palembanica seedlings. The experiment result showed that Eucalyptus was allelopathic against Shorea seedlings. Of the three plant portions, the fresh leaf had the most potential to obstruct the growth of Shorea seedlings.