Disease and related disorder management

Green Bean Breeding and Evaluation

Objective: Breed improved Bush Blue Lake green bean varieties with:

a. White and gray mold resistance
b. Improved plant architecture
c. High economic yield
d. Improved pod quality (including straightness, color, smoothness, texture, flavor and quality retention, and delayed seed size devel-opment)
e. Tolerance to abiotic stresses
Improve seed quality of materials in the breeding program to provide greater re-sistance to mechanical injury and low germination issues.

Management of Fusarium Diseases of Sweet Corn in the PNW: Seed Microflora Influence on Disease and Development of Fusarium-Free Seed

Principal Investigator: Cynthia M. Ocamb, Ext. Specialist & Associate Professor, Botany and Plant Pathology, OSU – Corvallis
Co-investigator: Nathan Miller, Postdoctoral Research Assistant, BPP, OSU
Collaborators: Jim Myers (Dept. of Horticulture, OSU) and Rogers Brand Vegetable Seed


Ascospore Trapping of Sclerotinia sclerotiorum in Snap Bean Fields and Root Rot Management (2010)

Report to the Oregon Processed Vegetable Commission

Cindy Ocamb
OSU Dept of Botany and Plant Pathology

Nathan Miller
Postdoctoral Research Assistant, BPP, OSU

David H. Gent
USDA-ARS, Corvallis

Robert B. McReynolds
OSU North Willamette Research & Ext. Center

Jim Myers
OSU Dept. of Horticulture


Field Evaluation of Carrot Seed Treated With Germicidal Light to Reduce Populations of Seed-Borne Xanthomonas hortorum pv.carotae

Objectives for 2010 and Accomplishments:

Conduct a field trial to evaluate the use of UV seed disinfestation on carrot growth and disease levels

Seed-borne pathogen levels were reduced in one carrot seed line when treated with UV light. That same line had the largest reduction in pathogen levels in healthy leaf tissue but the difference was not strongly significant (P = 0.068). Disease levels were reduced in one seed line but overall Xanthomonas populations and disease in the field were inconsistent.


On-farm Weather Station

 A network of local weather stations may provide the processed vegetable industry with more accurate weather forecasts. Local weather data may enhance our ability to predict crop developmental stages, insect pest population trends, and disease high-risk periods.


  • To establish, maintain, and evaluate an on-farm weather station for use in crop development, disease and insect pest population forecasting.

Green Bean Breeding


  • Breed Bush Blue Lake green bean varieties with high economic yield.
  • Improve pod characteristics including straightness, color, smoothness, texture, flavor and quality retention, and combine with delayed seed size development.
  • Incorporate white mold tolerance, and improve root rot tolerance while maintaining resistance to bean common mosaic virus.
  • Initiate populations to facilitate molecular marker assisted selection of desirable horticultural traits.
  • Evaluate novel genetic traits of potential benefit.

Genetic Transformation of Beans

For bean production in the Willamette Valley, perhaps one of the most obvious objectives is resistance to white mold (Sclerotinia) since this pathogen is difficult to control using chemicals and no native resistance has been found in common bean (Phaseolus vulgaris). It has been shown that the production of oxalic acid by the fungus Sclerotinia is the primary cause of pathogenicity. If the oxalic acid can be degraded rapidly by the plant, the symptoms of infection can be inhibited.