Cadmium Distribution in Field‐Grown Fruit Trees

Abstract

AbstractThe effect of soil applied Cd on Cd distribution in and growth of five species of fruit trees was investigated. Cadmium was applied at three rates (0, 5, and 10 mg kg−1 soil) as CdSO4 to orchard plots established at two pH levels, low (5.5) and high (6.5). Five fruit tree types were planted: ‘Gala’ apple (Malus domestica Borkh.) budded on M.26 (dwarfing) or MM.111 (semistandard) rootstocks, ‘Redskin’ peach (Prunus persica L.) on Lovell rootstock, ‘Stanley’ plum (Prunus domestica L.) on Myrobalon rootstock, and ‘Seckel’ pear (Pyrus communis L.) on seedling rootstock. The trees were grown for 6 yr, 7 yr in the case of pear, and leaf, bark, wood, fruit, and root Cd concentrations were monitored. Gala apple on both rootstocks accumulated very small concentrations of Cd, usually 0.1 mg kg−1 dry wt. in all tissues tested. Peach and plum were intermediate in Cd accumulation, but both still relatively low. Seckel pear had high Cd concentrations in all tissues including fruit flesh and peel. Pear leaf Cd concentrations were 2.0 mg kg−1 from the 10 mg kg−1 soil Cd application after 5 yr. Pear fruit peel and flesh showed elevated, although nonsignificant, Cd concentrations with increased Cd applied. There was little difference between bark and wood tissue Cd concentrations independent of tree type. Root Cd concentrations were highest for pear followed by peach and plum, and lowest in apple.