Effect of Alpha-Naphthalene Acetamide upon the Anatomical Structure of Cocklebur Grown in a Nutrient Medium Deficient in Calcium

Abstract

1. Plants of cocklebur were grown with a complete nutrient culture medium and in one lacking calcium. One-half of these plants were treated with alpha-naphthalene acetamide. 2. Symptoms of calcium deficiency, such as short upper internodes, downward cupping of the leaves, brown areas on the surface of the leaves and darkening of the margins, and drying of the stem tips, soon appeared on plants grown without calcium Treatment with alpha-naphthalene acetamide had only a slight effect on delaying symptoms of calcium deficiency at a temperature of 65⚬ F. At 75⚬ F., on the other hand, treatment of the plants with the acetamide greatly delayed the appearance of symptoms of calcium deficiency. At a temperature of 75⚬ F. plants grown without calcium were dry except for a few of the lower leaves after 46 days. Seventy-four days from the start of the treatment plants grown without calcium but treated with the acetamide first began to show slight symptoms of calcium deficiency. 3. The fourth internode of plants grow...