VIEW ARTICLE

Increased Endomycorrhizae of Cotton Roots in Soil Treated With Nematicides. G. W. Bird, Department of Plant Pathology and Plant Genetics, University of Georgia, Athens 30602; J. R. Rich(2), and Sue U. Glover(3). (2)(3)Department of Plant Pathology and Plant Genetics, University of Georgia, Athens 30602. Phytopathology 64:48-51. Accepted for publication 12 April 1973. DOI: 10.1094/Phyto-64-48.

Fumigation of nematode-infested field soil with nematicidally active rates of 1,2-dibromo-3-chloropropane (DBCP) or 1,3-dichloropropene and related C₃ hydrocarbons, resulted in significant increases in endomycorrhizal infection of cotton roots. While the mycorrhizal potentials of soils with different cotton productivity records were similar, the increases resulting from chemical treatments were expressed in different ways. Cotton roots grown in a DBCP-treated soil with a history of excellent cotton productivity, had significant increases in arbuscule, vesicle, and spore production by unidentified mycorrhizal fungi. In contrast, plants grown in DBCP-treated soil with a poor record of cotton productivity, had no significant increase in arbuscule production. The increase in vesicle production by the endomycorrhizal fungus, however, was significantly greater than in roots grown in the soil having the better productivity history. No endomycorrhizae were observed in cotton roots grown in methyl bromide-treated soils.