Ecology, Environment and Conservation Paper

EDTA HINDERS THE PROTECTION OF GROWTH OF AMARANTHUS CRUENTUS CV. NHAC-3, BY SALICYLIC ACID DURING COPPER TOXICITY

C.E. Umebese and O. T. Omoloba

Abstract

A study was carried out to investigate the protective action of salicylic acid on the growth of Amaranthus cruentus cv. NHAC-3 in Cu toxic soil (0.25 g kg-1) chelated with 1g kg-1 EDTA (ethylenediamine tetraacetic acid). Amaranth seedlings were treated with 3 mM salicylic acid (SA) by foliar application. Plants subjected to Cu toxicity only, had marked inhibition of growth (plant height, stem girth, dry biomass of root, shoot and inflorescence) compared with unstressed plants (control) and leaves were chlorotic and later necrotic and some abscised. Chelated Cu toxic soil caused further reduction (up to 50%) in the growth of plants. SA had protective impact on plant growth in Cu toxic soil inducing similar levels of growth as the control but this impact was markedly reduced in chelated Cu toxic soil. Results signify that SA can be used to alleviate the negative effect of Cu on growth in Cu toxic soils but this protective action is inhibited when Cu is chelated.