Alelopatski potencijal biljnog ekstrakta zelenih plodova oraha (Juglans regia L.)

Abstract

The aim of this study was to test the allelopathic effects of the plant extracts isolated from immature walnut fruits on the germination and early seedling growth of two weed species (Amaranthus retroflexus and Chenopodium album), and its phytotoxic effects on the germination and early seed growth of maize, Zea mays. Additionally, the goals was to also conduct an analysis of the plant extracts and determine its antioxidant properties. Antioxidant activity of the plant extracts were determined via its ability to neutralize DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and by testing their potential for iron reduction using the FRAP method. The inhibition of the measured parameters (total germination and seedling length) decreased proportionally, with the reduction of concentrations of plant extracts isolated from immature walnut fruits. Also, the seedling length parameter has shown greater sensitivity when compared with the parameters of total seed germination in both weed species. Even though the results of both biotests with seeds show a high inhibitory effect on the germination and early growth of the tested weed species, they also point to phytotoxicity in early growth of Z. mays seeds. Future research will be focused on the HPLC analysis of the plant extracts isolated from immature walnut fruits and their allelopathic effects on the early growth of plants of the tested species.