Journal of Nematology (2007) 39, p. 93 (Ingham et al.)

R. Ingham, M. Dillon, N. David and J. Delgado (2007)
Using green manure crops to suppress columbia root-knot nematode (Meloidogyne chitwoodi) in potato in the San Luis Valley
Journal of Nematology 39 (1), 93-93
Abstract - Society of Nematologists 46th Annual Meeting San Diego, California July 28-August 1, 2007
Abstract: Columbia root-knot nematode, CRKN (Meloidogyne chitwoodi), infests potato tubers and causes quality defects that may lead to crop rejection. CRKN is most commonly managed in the San Luis Valley (SLV) of Colorado with nonfumigant nematicides and less so with fumigants. Research in the Pacific Northwest of the US has demonstrated suppression of CRKN with green manure (GM) crops planted in late summer following a grain crop. However, the SLV has a very short growing season that is not long enough for a GM crop to be planted after a grain crop. High nematode control costs, low grain prices and water shortages led to grower interest in growing GM crops during the summer instead of a grain crop to reduce water use, improve soils and reduce nematode control costs. Field trials were conducted in 2004 and 2005 to evaluate GM crops planted in June and incorporated in August. Symptoms of CRKN in tubers were assessed in the following potato crops in 2005 and 2006. Prior to planting GM crops in 2004, CRKN averaged 1,900/250 g soil, but declined by potato planting in 2005 to 460 (radish), 440 (mustard), 170 (canola), 65 (sudangrass cv. Sordan 79) and 65/250 g in wet fallow plots. Initial CRKN averaged 800/250 g soil in 2005 but were reduced to 135 (mustard), 120 (sudangrass cv. Honeysweet), 25 (Sordan 79) and 1/250 g in wet fallow plots prior to planting potato in 2006. Symptoms of CRKN in tubers at harvest were low both years and met industry standards in all plots. However, incubating tubers to detect late season CRKN infection revealed high levels of culls following mustard (62%), radish (61%) and canola (72%) in 2005. Few culls were present after incubation in any treatment in 2006.
Database assignments for author(s): Russell E. Ingham

Research topic(s) for pests/diseases/weeds:
control - general
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Meloidogyne chitwoodi	Potato (Solanum tuberosum)	U.S.A. (SW)