ARS | Publication request: Utilization of biological control for managing root-knot nematodes.

Submitted to: Annual Brazilian Nematology Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 15, 2012
Publication Date: June 25, 2012
Citation: Timper, P., Jagdale, G., Davis, R.F., Parajuli, G. 2012. Utilization of biological control for managing root-knot nematodes[abstract]. Annual Brazilian Nematology Congress Proceedings. p. 43-48.

Technical Abstract: Our research goal is to enhance and conserve introduced and naturally occurring antagonists of root-knot nematodes (Meloidogyne spp.) to improve biological control. Towards that end, we have evaluated the effect of crop production practices such as rotation, nematicide application, and cover crops, on the abundance and activity of nematode antagonists. In one study, we found that rotating peanut (Arachis hypogaea) with other hosts for M. arenaria increased abundance of a host-specific parasite, Pasteuria penetrans, compare to rotations with non-hosts. In another study, we examined the effect of nematicides on predatory nematodes and the role of these nematodes in suppressing populations of plant-parasitic nematodes. The nematicide 1,3-dichloropropene (1,3-D) dramatically reduced predatory nematodes; however, their populations recovered by the next spring. The soil at the field site was suppressive to plant-parasitic nematodes; survival of these nematodes was reduced by 47%. Application of 1,3-D disrupted this natural suppression, but the level of suppression recovered by the next spring. In a third study, we determined whether planting a winter cover crop would improve the effectiveness of Paecilomyces lilacinus, a commercially-produced fungal parasite of nematodes. The persistence of this fungus is low in sandy soils. In a greenhouse study, we showed that growing cover crops before planting cotton increased suppression of M. incognita by P. lilacinus in the cotton crop. We speculate that the cover crops reduced water loss in the sandy soil and improved fungal persistence and growth. These studies demonstrate that we can enhance biological control by modifying crop production practices.