Vertical Distribution of Meloidogyne arenaria Juvenile Populations in a Peanut Field

Abstract

The relation between soil depth and population development of Meloidogyne arenaria juveniles was studied for a 15-month period beginning in January 1986 in a peanut field at the Wiregrass substation, Headland, Alabama. The soil was sandy loam with 1.0% (w/w) organic matter and had been in peanut culture for the preceeding 10 years. Juvenile numbers in soil were highest in the top 30-40 cm of the soil profile. A fairly constant but low ( 20 juveniles/100 cm soil) population of juveniles was observed throughout the study at depths below 40 cm. The relationship between numbers of juveniles (J) and soil depth in cm (X) conformed to the equation: J = A ¿cdot B{(l/X)0 ¿cdot X^C, where A, B, and C are constants and X 0. The equation predicted largest numbers of juveniles at ca, 12 cm depth. The greatest fluctuations in juvenile population size occurred in the top 30-40 cm of the profile. Juvenile populations were highest just prior to peanut harvest and lowest in the late-winter-spring p