Pratylenchus penetrans is a major nematode pest of vegetable crops in Japan. We investigated
P. penetrans population dynamics and cabbage growth under the year-round application of sawdust cattle manure compost for continuous cabbage cropping (2002-2009) at Tsukuba, Japan. Cabbages were cultivated twice a year, during spring and autumn. Chemical fertilizer (CF), manure compost (MC) + 1/5CF, CF + 3/5MC + crop residue (CR), a triple amount of MC + 1/5CF, and 3MC + CR were applied to the field before transplanting the cabbages. Both the initial population (
Pi) and final population (
Pf) of
P. penetrans were significantly high in CF, low in 3MC + 1/5CF and 3MC + CR, and average in MC + 1/5CF and CF + 3/5MC + CR in 2003-2005 and 2008-2009. Both
Pf/
Pi during cultivation and the decreased rate of
Pi/
Pf after cultivation showed no clear tendencies among compost treatments. In this study, host plant growth did not appear to be markedly restricted by the high densities of
P. penetrans. By applying Seinhorst’s formula on the
Pi and
Pf of
P. penetrans, we obtained 2 curves for CF and 3MC + CR, with 16.45 and 4.54 representing“ equilibrium density”, respectively. Pot experiment results supported the field experiment results, whereby the number of
P. penetrans decreased as the quantity of MC increased (from 0 to 3%w/v). On the basis of these results, we concluded that manure compost application could have a suppressive effect on
P. penetrans population dynamics.
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