NOTES ON THE NUTRIENT REQUIREMENTS AND THE HISTOLOGY OF THE CRANBERRY (VACCINIUM MACROCARPON AIT.) WITH SPECIAL REFERENCE TO MYCORRHIZA

Abstract

The nutrition of the cranberry, as well as of various other members of the Ericaceae, is complicated by the fact that under ordinary cultural conditions the green plant exists in close association with a fungus. Although an association of a fungus with the roots of a higher plant is called a mycorrhiza, the literal definition of the word must be extended somewhat to include the condition that exists in the Ericaceae, for in this family the fungus is not confined to the roots, but is coextensive with the growth of the plant, occurring in practically every organ. The fungi associated with the Ericaceae were named by Ternetz (14) in 1907 as strains of Phoma radicis, and have since been isolated by Rayner (9) and other workers. The most complete summary of the work that was done on mycorrhiza by various workers prior to 1927 is to be found in a monograph by Rayner (10). Field experiments by various workers (1, 12, 15) have led to conflicting reports in regard to the value of various nitrogenous fertilizers. It is possible that the presence of the endophytic fungus may make available forms of nitrogen that could not otherwise be utilized by the green plant. The present project was undertaken in an attempt to contribute to our knowledge of the fertilizer requirements of the cranberry, and of the structural and nutritional relationships between the cranberry and its endophyte. This paper represents only a preliminary report ; it is hoped that a continuation of the work will yield further results.