DOI: https://doi.org/10.55373/mjchem.v27i1.122

Keywords: Baeckea frutescens; Cucumis melo var. Inodorus cv. Manis Terengganu 1; GCMS; Quninic acid

Abstract

The study investigates the effects of Baeckea frutescens methanolic leaf extract on the growth and disease incidence of Melon Manis Terengganu (Cucumis melo var. Inodorus cv. Manis Terengganu 1), alongside its chemical profile through GCMS analysis. A 1 mg/mL of extract was applied under field condition using two methods: injected near the root (TI1), and foliar spray (TS1), twice a week following a Randomized, Completely Blocked Design (RCBD). The results revealed significant improvements in plant growth with increases in plant height (TI1;26.49%, TS1;14.72%), leaf number (TI1;9.79%, TS1;4.22%), ovary length (TI1;14.83%, TS1;13.58%), and fruit weight (TI1;19.91%, TS1;10.39%). Disease incidence was also notably reduced, with control plants (TS0 and TI0) exhibiting over 50% disease occurrence at 60 days, while treated plants (TS1 and TI1) showed only 10.4% and 35.4% disease incidence, respectively. GCMS analysis identified quininic acid as the most abundant compound (11.49%), followed by d-fructose (11.23%), d-mannose (10.40%), d-glucose (8.75%), sucrose (8.61%), muco-inositol (7.20%), and gallic acid (4.14%). In conclusion, the extract of B. frutescens has a significantly positive impact on enhancing growth performance and decreasing disease incidence compared to the control. This could be due to the chemical constituent of quininic acid, which is the most abundant.