The Effects of Crude Extracts from Black Afara Leaves on Plant Growth Inhibition

Abstract

Weeds negatively impact agriculture in both production and quality. They compete for water and essential nutrients for plant growth, leading to reduced yields and making harvesting more difficult and time-consuming. Economically, weeds increase production costs, such as labor wages and herbicide expenses. Furthermore, they serve as hosts for diseases and pests. While most farmers rely on chemical herbicides, continuous and improper use can lead to residues in soil, water, air, crops, and the environment. Currently, there are approaches to reducing chemical use by employing naturally active ingredients that are easily biodegradable and safe for users and consumers. Some plants can release secondary metabolites that inhibit the growth of other plants; a phenomenon known as allelopathy. This research studied the inhibitory effects of crude extracts from fresh and dried Terminalia catappa leaves on experimental plants tested on tissue paper-lined petri dishes. At concentrations of 0, 1,000, 5,000, 1,0000, 15,000, 20,000, 25,000, and 30,000 ppm, the inhibitory effect of fresh and dried Terminalia catappa leaf extracts on the growth of monocotyledonous plants (rice) and dicotous plants (Chinese cabbage and eggplant) was significantly different across all concentrations. Increasing the concentration resulted in greater inhibition of seed germination, stem length, and root length in all three experimental plants. Therefore, Terminalia catappa leaf extract has the potential to control plant growth and represents an alternative for reducing the use of chemical herbicides.