The problem is most commonly observed on pin oak, azalea and rhododendron. Not all mineral deficiencies are iron-related, however. In these same high soil pH sites, maples may develop manganese deficiency and pecans may show zinc deficiency. Symptoms Chlorosis of younger leaves is the most common distinctive symptom of iron deficiency. As the problem worsens, newest leaves may become nearly white because leaf veins and areas between veins lack any green or yellowish-green coloring.
Affected leaves are generally smaller than normal.
Brown, necrotic areas may develop along leaf margins and between veins in severe cases. These symptoms may be similar to those caused by other nutritional disorders. To positively identify the problem you need to have a soil test and, in many cases, a leaf analysis. When iron deficiency symptoms progress further, some older affected leaves may become tinted reddish brown. Leaf drop, beginning at the terminals, may occur.