Observations on the distribution of Meloidogyne spp. in a vineyard soil.

In an investigation on nematode dist r ibut ion in a vineyard (1), difficulty arose in determining tile Meloidogyne spp. present. Chromosomal analysis indicated the presence of at least six populations, representing four species (2). T h e objective of this study was to determine any differences among the Meloidogyne populat ions in their distr ibution in the soil and between vines. T o m a t o seedlings (c.v. 'Pearson') were planted in seventy 500-cm :~ soil samples [from different regions of the root zone of six vines (1)] and grown in a greenhouse for 6 weeks. Perineal patterns were cut from Meloidogyne females removed from tile root systems of these plants. A minim u m of six patterns was obta ined from each plant. T h e patterns were of the M. incognita and M. arenaria types. None of the patterns resembled M. hapla or M. javanica, which were observed in the original study (2). T h e percentage of M. incognita patterns was greater than that of M. arenaria (Fig. 1) when data were analyzed after arcsin t ransformat ion (3). T h e rat io of M. incognita to M. arenaria patterns throughout the vine root zone did not vary with depth (Fig. 1). T h e percentage of M. incognita in patterns taken from soil samples from each of the six vines did not differ (range 60-