Effects of Aqueous Extracts Obtained from Two Radish Cultivars (Raphanus sativus L. and Raphanus sativus L. var. radikula) Using Liquid Nitrogen Is Germination of Barnyard Grass (Echinochloa crus-galli) and Allelopathic Effect on Seedling Growth

Abstract

This study was conducted to evaluate the allelopathic effects of extracts obtained from different parts (root, stem and mixed) of radish varieties ( Raphanus sativus L. and Raphanus sativus L. var radicula ) on germination and seedling growth of barnyard grass as well as the identification of the phytotoxic chemicals responsible for allelopathic activity. During the extraction process, the plant parts of the radish varieties were frozen with the help of liquid nitrogen and then, crushed and powdered. Aqueous solutions prepared with certain doses of radish powders (0%, 1%, 2%, 4%, 8%, 16%) were applied to weed seeds. The seeds were kept in an incubator at 25 °C for 15 days. At the end of the period, the germination percentage of the weed seeds was determined by measuring the length of the root and stem. The results indicated that the allelopathic potential of radish on barnyard grass varied depending on the varieties, plant parts and extract concentrations tested. Among the test parameters, the highest allelopathic effects were obtained from the root elongation of barnyard grass. Stem extracts of little radish were the most inhibitory for all test parameters. As a result of GC-MS analysis of little radish stem extract, the presence of many bioactive compounds that may be the source of the allelopathic effect has been revealed. Overall, these results suggest that little radish could be used in bioherbicide development. Keywords: liquid nitrogen, allelopathy, turnip, barnyard grass, germination, elongation, DOI: 10.7176/JBAH/12-14-02 Publication date: July 31 st 2022