In the final stages of the disease, the shoots die back from the tips. Usually the die-back is confined to the current year's growth, but it sometimes extends to older, larger branches. The zinc level is usually adequate in New Mexico soils. This condition is usually more severe in sandy soils and soils with high phosphorus levels. Zinc deficiency also can be severe when trees are planted in old barnyards and corral sites, because zinc availability is low in soil with high organic content.
Branch die-back is typical in trees deficient in zinc.
Small, yellow leaves appear when zinc levels are low. The leaves on the left are healthy. Note how an abnormal number of branches have developed in a limited area. Controlling Zinc Deficiency Zinc deficiency may be corrected and controlled by applying zinc fertilizers. Foliar sprays with various zinc compounds are generally the most successful means of correcting zinc deficiency in trees.