Hackberry Decline, Herbicide Drift, Celtis occidentalis
For several years a decline of hackberry (Celtis occidentalis L.) leading to eventual tree mortality has been evident in northwest Iowa. A search for the cause of the decline in trees in and near Odebolt, in Sac County, Iowa, has included investigation of soil abnormalities, nutrient deficiencies, pathological or viral vectors, entomological agents, climatological extremes, and physiological or environmental factors. The decline could not be attributed to any disease or insect problem. Recurring symptoms were those of herbicide damage. Indications of herbicide damage included cupped, chlorotic leaves, lack of apical dominance, enlarged bud size, and epinastic twigs. In addition, increased soil nitrate levels may indicate abnormal plant nitrite levels caused by herbicidal action.
Proceedings of the Iowa Academy of Science
©1976 Iowa Academy of Science, Inc.
Hibbs, Robert H.
"Decline of Hackberry Attributed to Ambient Herbicide Drift,"
Proceedings of the Iowa Academy of Science, 82(3-4), 187-190.
Available at: https://scholarworks.uni.edu/pias/vol82/iss3/13