Abstract

Odoi, N. 1976. Index of plant sensitivity to air pollution. Grounds Maintenance 11(2): 68, 70, 72, 74-76.

Pollution injury is difficult to diagnose and is often confused with other causal factors, ranging from nutrient deficiencies to soil moisture extremes or even simple aging. This is especially true of chronic injury which takes place almost imperceptibly over a period of several years. Even if the pollution dose is not lethal, it may interfere with the plant’s physiological processes causing growth rate decline, premature leaf drop or an increased vulnerability to disease and pests. Pollution is not clearly implicated as a cause, but plant and financial losses result. To diagnose pollution injury, first rule out other possible causes of damage. Consider the probability of pollution as a cause in terms of distance from source, weather conditions, wind, etc. Pollutants are not as highly specific as most pests and diseases, so a variety of plants should be affected. Patterns of injury may be apparent. Since pollutants enter the plant through the stomata of the leaves, the main symptoms can be seen on the leaf surface. Damage is most common in late spring and early summer when the leaves have not yet matured and are still quite sensitive.

• © 1977, International Society of Arboriculture. All rights reserved.