ALLELOPATHIC PROCLIVITIES OF <em>ACACIA</em> <em>NILOTICA</em> (L.) WILLD. EX DEL.

Abstract

Aqueous extracts of bark and leaf of Acacia nilotica (L.) Willd. ex Del. were tested for potential inhibitory effects on eight arable crops. Seed germination of the arables was significantly inhibited by the extracts. To a greater extent, radicle and plumule growth too were affected. The inhibition by bark extract was greater than by leaf extract. It is assumed that the effective substances are phytotoxins, mostly tannin, which are present in the extract. However, the response of the crops was disparate, tomato being the most susceptible and sunflower the least. The poor growth reported in some areas, of crops irrigated from tanks, the foreshores of which have been grown to stands of A. nilotica may be related to tannin leached mostly from bark of the tree in rain wash.