High zinc concentrations in the growing medium contribute to chlorosis in blueberry

An experiment arranged in a randomized complete block design with four replications of two cultivars x six pH levels x four Zn levels was conducted to determine if Zn caused leaf chlorosis in rabbiteye (Vaccinium ashei Reade cv. Climax) and southern highbush (mostly V. corymbosum L. cv. Bladen) blueberry. 'Bladen' accumulated more foliar Mn and Zn than 'Climax', but Fe concentration was similar in the two cultivars. Leaf chlorosis ratings were similar for the two cultivars. Solution pH had no significant effect on Mn, Zn, or Fe leaf concentration or degree of chlorosis. Zinc level in the nutrient solution affected leaf concentration of Mn and Zn brit not of Fe. A significant linear increase in chlorosis resulted from increasing Zn solution concentration from 30 to 120 mg . L(-1). We conclude that high levels of Zn may induce leaf chlorosis in rabbiteye and southern highbush blueberry.