Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Plants, Soils, and Climate


D.W. Thorne


Chlorosis, the yellowing of plant leaves, results from reduced synthesis of chlorophyll. It is caused by a deficiency or an unbalance of essential nutrient elements. The amount and pattern of yellowing varies with the cause and severity of the disturbance. Chlorosis results in reduced vigor of the affected plants and a corresponding loss in quantity and quality of the product grown. In severe cases chlorosis may lead to the eventual death of the plant.

Lime-induced chlorosis refers to a chlorosis occurring on high lime soils. It affects principally horticultural plants. The disease is found in about 23 percent of Utah orchards.

Lime-induced chlorosis is characteristically accompanied by high potasseium in the affected leaves. The hypothesis had been offered that this high potassium is a cause of lime-induced chlorosis. The object of this study is to investigate the validity of this hypothesis.