VIEW ARTICLE

Effect of Phosphate Fertilization on Yield of Mycorrhizal and Nonmycorrhizal Soybeans. J. P. Ross, Plant Pathologist, Plant Science Research Division, ARS, USDA, P. O. Box 5397, Raleigh, North Carolina 27607; Phytopathology 61:1400-1403. Accepted for publication 6 July 1971. DOI: 10.1094/Phyto-61-1400.

Yields from soybeans grown in fumigated soil were not related to phosphate fertilization levels when plants were infected by the mycorrhizal fungus, Endogone; yields from nonmycorrhizal soybeans similarly fertilized were directly related to phosphate applications. At low, medium, and high phosphate, yield increases due to Endogone mycorrhizae were 122, 67, and 12%, respectively. Concentrations of N, P, Ca, and Cu in foliage of mycorrhizal plants were greater than those from non-mycorrhizal plants at the various phosphate levels. Phosphorus concentration in foliage of mycorrhizal plants at the lowest phosphate level was greater than that in nonmycorrhizal plants at the highest phosphate level. Nonmycorrhizal soybean roots appear to be inefficient phosphate-absorbing organs, and mycorrhiza may aid plants in functions other than phosphate uptake.