Estimation of DMC in the root samples was based on the oven dry method. Briefly, collected roots were washed, peeled and chopped into 1 cm thick pieces to a total weight of 200 g (fresh weight). Samples were dried to constant weight in an oven that was maintained at 72°C. Upon attainment of constant weight (48 h), samples were immediately weighed (dry weight). Percentage DMC was computed by dividing the dry weight by the fresh weight and multiplying by 100.