Management Problem Gallery

Zinc Deficiency
Image courtesy of Becky Carroll, Oklahoma State University

Zinc Limb Dieback
Image courtesy of Becky Carroll, Oklahoma State University

Management Problem

Name: Zinc Deficency

Secondary Name: Rosette

Source: Zinc deficiencies often become visible when leaf Zn is less than 40 ppm. Zinc availability is reduced on alkaline soils. Even under ideal conditions, uptake of zinc is slow, thus foliar zinc sprays are the fastest method of supplying zinc to the tree. Leaf absorption of zinc is not efficient after leaves harden off. Properly timed sprays are required to eliminate any deficiency problems.

Description: Rosette begins as chlorosis and curling or twisting of young leaflets. The condition is first visible in the the terminal leaflets. As the problem progresses, further chlorosis and wavy leaf margins develop including narrowing leaflets, interveinal necrosis, and terminal dieback. Affected trees may appear rusty brown or yellow-green, especially near the tops of the trees.