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BEAN BACTERIAL DISEASE(s) - BACTERICIDE DECISION STRATEGY
See Bean Pesticide Summary for pesticide details
[Halo Blight, Bacterial Brown Spot &/or Common Bacterial Blight]
Colorado State University Integrated Pest Management Program
CHECKLIST FOR APPLICATION  Your Score
Current Season Rainfall, Dew, Humidity from Planting to V - 4 Stage   
Above Normal: 2  Normal: 1 Below Normal: 0
Current Season Temperature from Planting to V - 4 Stage   
Below Normal: 2  Normal: 1 Above Normal: 0
Forecasted Rainfall, Dew, Humidity Between V - 4 and R - 4 Stages   
Above Normal: 2  Normal: 1 Below Normal: 0
Forecasted Temperature Between V - 4 and R - 4 Stages   
Below Normal: 2  Normal: 1 Above Normal: 0
Bean Rotation less than 3 years and/or Volunteer Beans Within 2 miles from Field   
Yes: 4  Unknown: 2 No: 0
Variety Reaction to Bacterial Disease(s)   
Susceptible: 4  Unknown: 2 Resistant: 0
Initial Bacterial Lesions Confirmed on Numerous Plants Prior to R1 (Early Flower)   
Yes: 4  No: 0
Initial Bacterial Lesions Confirmed on Numerous Plants Prior to R3 (Early Pod Set)   
Yes: 2  No: 0
Total Score:  

ENVIRONMENTAL THRESHOLDS (weekly) for Disease Forecast:
Temperature: Normal = average high temperature of 86 F
Moisture: Normal = 0.25 inches of rainfall
DISEASE RISK SUMMARY - If the Total Score was:

more than 15 = High Risk 10 - 15 = Moderate Risk less than 10 = Low Risk
If the variety is susceptible and the total score was 10 or higher, treatment with a labeled copper-based bactericide such as Champ, Kocide, Nordox, Cuprofix, or TopCop as a protectant should be considered during the rapid vegetative (V3) to the early seed fill (R5) growth stages. Follow a 7 to 10 day interval between sprays, depending upon disease pressure until the R5 growth stage is reached.
Note: As with any pesticide, always read and follow instructions and precautions. Refer to the Dry Bean Growth Stage Chart, and incorporate other Integrated Pest Management approaches such as crop rotation, sanitation, certified seed, plant resistance, tillage, moderate irrigation and fertility, and timely scouting.
[Checklist adapted for Colorado and surrounding region by Dr. H. F. Schwartz, M. S. McMillan, and K. L. Otto, 6/98]

Bacterial Disease - IPM STATEGY for Edible Bean (dry, snap, seed):

  • Rotate to exclude susceptible host crops (i.e., sunflower, soybean, canola, pea) for 3 + years; examples of non-host crops are small grains and corn
  • avoid planting in fields with a history of disease during the last 3 - 5 years
  • plant resistant or less susceptible varieties if available
  • follow recommended plant population - row & plant spacing
  • soil test and use a moderate fertility program; e.g., not to exceed 75 - 100 lb N/A
  • incorporate fall and/or spring tillage to eliminate carryover seed and volunteer beans in last year's bean fields, promote root health and moisture drainage in this year's bean fields
  • monitor irrigation scheduling to avoid flowering-period deficiency but late-season saturation
  • utilize timely scouting, disease forecasting, and weather monitoring services
  • when justified, use timely applications of recommended bactericides at 30 - 45 days post- emergence; maintain protection throughout flowering and early pod set