Boron Deficiency in Agave
The first signs of boron deficiency in agave are yellow spots, most numerous near the tip, on both surfaces of the leaf. These are followed by the formation in the epidermis of ramifying finger-like depressions from the leaf margin, which may later become suberized. In sand culture experiments, symptoms have included hooked leaf tip and leaf spine that is absent or reduced to a white hair.
In cases of severe deficiency, the growing point becomes disorganized and the leaves are short, narrow, twisted, and sometimes split. The plants have a flat-topped appearance.