Effects of Vesicular-Arbuscular Mycorrhizal Fungi on Infection of Tamarillo (Cyphomandra betacea) by Meloidogyne incognita in Fumigated Soil. Karen M. Cooper, Division of Horticulture and Processing, Department of Scientific and Industrial Research, Auckland, New Zealand. Gordon S. Grandison, Entomology Division, Department of Scientific and Industrial Research, Auckland, New Zealand. Plant Dis. 71:1101-1106. Accepted for publication 5 May 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-1101.

The effects of vesicular-arbuscular mycorrhizal (VAM) fungi on infection of tamarillo (Cyphomandra betacea) plants by root-knot nematodes (Meloidogyne incognita) were studied in fumigated soils with and without supplementary phosphate fertilizer. Nematodes severely reduced plant growth. In dually-inoculated plants, mycorrhizal infection improved plant growth and suppressed nematode reproduction and development in roots. Nematode infection and development were less in plants preinfected with mycorrhizal fungi than in plants inoculated simultaneously with both organisms. The benefit achieved by mycorrhizal inoculation could not be duplicated by adding phosphate fertilizer and was not therefore due merely to improved phosphorus nutrition of the host.