Organic mulches and irrigation affect Mesocriconema xenoplax and Pratylenchus penetrans under cherry.

Mesocriconema xenoplax and Pratylenchus penetrans are important plant parasitic nematodes of cherry trees, but little is known of how soil and water management practices affect the buildup of either species in cherry orchards. A split-plot field experiment was initiated in 2014 to compare five soil treatments (untreated control, preplant fumigated, compost, bark chip mulch, compost+bark chip mulch) under drip and microsprinkler irrigation. Plant-parasitic nematode populations were monitored through 2023. The population of M. xenoplax was initially detected in only 3% of the 60 plots whereas P. penetrans was initially present in all plots. By 2023, M. xenoplax were detected in 70% of plots with maximum population density among plots of 834 M. xenoplax 100 cm-1 soil. Mesocriconema xenoplax became more abundant in compost plots and fumigated plots than in untreated plots, and more abundant under drip than microsprinkler irrigation. In contrast, P. penetrans were least abundant in compost plots and less abundant under drip than microsprinkler irrigation. The opposing responses of these two nematode species illustrate tradeoffs in pest pressures that can occur with changes in orchard soil and water management practices, obscuring effects of either species on tree growth.