ARS | Publication request: Update on the use of disease-suppressive crops in potato rotations

Submitted to: Northeast Potato Technology Forum
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2010
Publication Date: March 10, 2010
Citation: Larkin, R.P., Honeycutt, C.W., Olanya, O.M., He, Z. 2010. Update on the use of disease-suppressive crops in potato rotations. Northeast Potato Technology Forum. pages 10-11.

Technical Abstract: Numerous soilborne diseases can be persistent, difficult-to-control problems in potato production. The use of disease-suppressive crops, as rotation, cover, or green manure crops, can potentially reduce multiple soilborne potato diseases. Brassica spp. and related plants suppress diseases through multiple mechanisms. The roles and uses of these and other potential disease-suppressive rotation crops in potato production systems have been evaluated in various field trials over the last several years in Maine. In previous trials, canola (as a harvested crop) and rapeseed (as a green manure) in 2-yr rotations with potato consistently reduced black scurf and common scab by 30-60% relative to other 2-yr rotations. Mustard blend (‘Caliente 119’) and sorghum-sudangrass green manures reduced Verticillium wilt (early-dying) by 18-30% in a severely-infected field, reduced other soilborne diseases, and also significantly increased tuber yield. Canola, rapeseed, and mustard rotations, also reduced powdery scab by 15-50% in various on-farm trials. An overview summarizing all field trials involving Brassica rotation crops conducted over the past several years in Maine indicates that, although results vary by field and year, positive effects on yield and disease reduction have been observed in the majority of trials, with yield improvements up to 22% and disease reductions ranging from 20 to 90% for multiple pathogens. This research demonstrated that effective rotations and use of Brassica crops can substantially reduce soilborne disease problems, but cannot completely control them. Good rotation strategies should be used in conjunction with other crop and soil management approaches to achieve more sustainable crop production.