Dry beans are poor competitors and herbicide options are limited. Start with a field with low perennial weed pressure. Maximize crop competitiveness by untilizing narrower row width,s adequate seeding rates and appropriate fertility. Layer herbicides, using a pre-emergent option with residual activity and timely post-emergent applications to target weeds when small.
Dry beans are susceptible to the root rot complex, including Fusarium spp., Rhizoctonia solani and Pythium spp.. Fungicide seed treatment can offer protection against these diseases for up to three weeks after planting. Fusarium root rot is the most common seedling disease in Manitoba. Severity of root rot infection typically reflects soil moisture conditions of a given year.
Scout for foliar and stem diseases from July to early September. The most common dry bean foliar disease in Manitoba is the bacterial blight complex (common bacterial blight and halo blight) which often infects plants following damage from hail, strong storms or mechanical damage. Severity levels of bacterial blight are often low and not expected to be yield limiting. Plant disease-free seed. Foliar products are available, however, their effectiveness has been variable to-date.
The main yield-limiting disease of concern controlled by fungicides in dry beans is white mould (Sclerotinia sclerotium). Fungicides for this disease are purely preventative. Use the Fungicide Decision Worksheet for Managing White Mould in Dry Beans to determine if a fungicide application may protect yield in your field.
Soybean cyst nematode has been reported in central Manitoba at low population levels. Dry beans are susceptible to this pest.
- Foliar fungicide decision making in dry beans
- White mould fungicide efficacy research in dry beans – Michal Harding, Alberta Agriculture
Monitor for wireworms, seedcorn maggot and cutworms from May to June. Most insecticide seed treatments protect against wireworms and seedcorn maggot only. There is one seed treatment option for cutworm management in dry beans – Lumivia CPL (chlorantraniliprole). Assess the need for protection on a field-by-field basis.
Scout for leaf and pod feeding insects such as grasshoppers, green cloverworm and potato leafhopper from June to August. Western bean cutworm has not yet been detected in MB.
Potato leafhoppers do not overwinter in Manitoba. In some years, populations from the south arrive at levels that can be of concern in dry beans.