Influence of excess copper on sugarcane metabolism and nutrient composition

Single bud setts of sugarcane (Saccharum Officinarum hybrid, CoLk 8102) planted in polyethylene pots filled with refined sand in complete nutrient solution at three levels of copper, viz. 0.065 (control), 65.0 and 130 (excess) ppm as copper sulphate. Results obtained showed a decrease in area and length of leaf, plant height, root number and length, fresh and dry weight of different plant parts due to excess Cu supply. Excess Cu decreased chlorophyll a, b and carotenoids contents and catalase activity, while peroxidase activity was increased. A significant reduction in calcium uptake was observed under excess Cu. Cu concentration increased significantly in different plant parts with an increase in Cu supply. High levels of Cu depressed the uptake of Fe and Zn in leaf and shoot. Above findings suggested that excess copper adversely affected growth characteristics, availability of essential nutrients and concentration of chlorophyll and carotenoids pigments which may reduce the net photosynthetic rate and ultimately resulting in low biomass of sugarcane plant.