Study of the allelopathic activity of Garcinia pedunculata Roxb

Abstract

The allelopathic properties of plants can be used as an alternative weed control method to reduce the use of synthetic herbicides. Accordingly, the present study was carried out to determine the allelopathic activity of Garcinia pedunculata. Six different concentrations of aqueous methanol extracts of G. pedunculata fruit were prepared and used to determine their effect on the growth of eight test plants: alfalfa (Medicago sativa L.), cress (Lepidum sativum L.), lettuce (Lactuca sativa L.), rapeseed (Brassica napus L.), barnyard grass (Echinochloa crus-galli (L.) P. Beauv.), foxtail fescue (Vulpia myuros (L.) C.C. Gmel.), Italian ryegrass (Lolium multiflorum Lam.), and timothy (Phleum pratense L.). The test plants were grown in Petri dishes and after 48 h incubation, the length of the roots and shoots of the seedlings was measured and compared with control seedlings. Experiments were carried out in a completely randomized design (CRD). Analysis of variance (ANOVA) of the data was performed using the SPSS statistical package, and the I50 values were measured from a regression equation. The extracts at each concentration significantly inhibited the shoot and root growth of all the test plants, except the concentration of 0.001 g dry weight equivalent extract/mL, compared with control. At a concentration of 0.3 g of dry weight equivalent extract/mL, the shoot and root growth of all the tested plants were completely inhibited, except the shoot growth of barnyard grass. The degree of inhibition increased in line with increased extract concentration. The shoots of alfalfa and the roots of barnyard grass were determined to be the most susceptible to the G. pedunculata extract based on the concentration of extract resulting in 50% (I50) growth inhibition of the test plants. These results suggest that G. pedunculata may have allelopathic potential and may possess allelochemicals. From our study, we can conclude that G. pedunculata could be developed as an eco-friendly weed control option.