Copper toxicity in young mango plants.
Kotzé J. M.
Author Affiliation: University of Pretoria, Pretoria 0002, South Africa.
: 71-72
Abstract : An experiment was conducted to study the effects of copper on potted mango cv. Keitt and on bean and maize sown in the pots previously planted with mangoes. Copper oxychloride was applied at 3, 88, 263 and 1043 ppm. Keitt showed normal growth at 3 and 88 ppm copper oxychloride, however, root stunting and stubby roots were observed at 88 ppm. At 263 ppm, the leaves appeared to be smaller and the growth was slightly stunted. Root stunting and stubby roots occurred. At 1043 ppm, high leaf fall, very short internodes on new growth and small malformed leaves (spoon-shaped) were observed. The leaves turned chlorotic after 8 weeks. Root growth was low and less stubby roots were observed than at 88 and 263 ppm. Similar results were obtained with maize and bean seeds. Both showed stubby roots at 88 and 263 ppm. At 1043 ppm, most seeds rotted in the soil and the few plants that managed to emerge were severely stunted with almost no roots.