Unhealthy leaf development may be an indication of copper deficiency. The symptoms typically appear at the tips of dicotyledonous plants or in the new shoots -- called tillers -- that spring from the roots of cereal grains. Leaves may become pale or yellowish -- a condition known as chlorosis. They may become curled or twisted, especially at the leaf tips. The upper portion of cereal grain leaves may die and drop off. The leaves of dicotyledons may droop -- beans and apple trees are good examples of dicotyledons.
Stems also show telltale signs of copper deficiency, especially in newly-developing branches. In cereal grains, the stems of new shoots may show the most pronounced effects. The stems become flaccid, and many tillers will die. The stems will not grow as fast as they usually do, and their final length will be shorter than usual. Lacking their usual firmness, the stems may bend and break as the grain head develops.
Copper deficiency may prevent fruit from developing normally. Fruit may abort soon after its development has begun. In cereal grains, the heads will not develop as rapidly as they normally do, and many spikelets will consist of pure chaff without any grain.
Copper deficiency also affects conifer trees. Their branches and even their trunks become distorted. The apparent cause is insufficient hardening of the wood, according to the 1990 study "Copper Deficiency in Coniferous Trees" by N.D. Turvey and B.R. Grant.
Copper deficiency may impart a sickly, stunted appearance to the plant. Dark spots indicating tissue death may appear in various places. Even when pathological symptoms do not appear, copper deficiency will retard plant growth, and fruit or grain production will decline.