PHYTOTOXIC POTENTIAL OF CELTIS AUSTRALIS L. (FAMILY ULMACEAE) AGAINST FOUR CROP SPECIES

Abstract

Bioassays were conducted to test the phytotoxic potential of Celtis australis against Trifolium alexandrinum, Brassica campestris, Triticum aestivum and Lactuca sativa under laboratory condition. Aqueous extracts from twigs and leaves were obtained by soaking 5 and 10g plant material in 100 ml distilled water for 24 and 48hr durations. Aqueous extracts significantly delayed/retarded the germination and reduced the plumule and radicle growth of all the four test species. Generally, extracts soaked for 48h especially 10 gm/100ml were inhibitory than 24h extracts of 5 or 10gm material. Extracts from twigs were inhibitory to germination of wheat while same extracts inhibited the plumule growth of B. campestris. Radicle growth of T. alexandrinum was inhibited more by twig extracts. Hot water extracts from twigs were less inhibitory than leaf extracts. Litter and mulch also significantly delayed the seed germination and retarded the overall growth of seedlings of all test species. The number and length of seminal roots of T. aestivum was suppressed by all aqueous extracts, added litter and mulch. The inhibitory response depended upon the test species, concentration, soaking duration and physiological parameters. The results suggested that Celtis australis has strong phytotoxic potential.