Copper deficiency occurs very seldom. Affected plants show chlorosis on expanding and mature leaves. Heart necrosis might also be caused by Cu undersupply.
Made worse by
Organic soils. Chalky soils. Sandy soils. Reclaimed heathland. High nitrogen applications.
Lignin formation, chlorophyll performance and regulation of superoxide radicals. Necessary for blue pigment plastocyanin, seen in broccoli florets.
Copper deficiency (Photo: Chinese cabbage)