Disease and related disorder management

Green Bean Breeding and Evaluation (2011)

Report to the Oregon Processed Vegetable Commission

Jim Myers and Brian Yorgey

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

Evaluation of carrot seed treated with germicidal light to reduce populations of seed-borne Xanthomonas hortorum pv. carotae

Principal Investigator: Cynthia M. Ocamb, Ext. Specialist & Associate Professor
Botany and Plant Pathology, OSU - Corvallis
Telephone: (541) 737-4020

Co-investigator: Nathan Miller, Postdoctoral Research Assistant, BPP, OSU

Evaluation of carrot seed treated with germicidal light to reduce populations of seed-borne Xanthomonas hortorum pv. carotae

Objectives and Accomplishments for 2011:

1. Conduct a seed evaluation of several fresh carrot seed lots for Xanthomonas contamination levels and test the effects of UV light, hot water, and hydrogen peroxide on seed contamination.

2. Establish a field trial to evaluate the use of UV seed disinfestation on carrot growth and disease levels using fresh seeds.

Management of Fusarium diseases of sweet corn in the PNW: Seed microflora influence on disease and development of Fusarium-free seed

Objectives for 2011 and Accomplishments:

1. Examine the yield and disease levels of sweet corn plants grown from seeds treated with germicidal light.

2. Evaluate biological applications to sweet corn seed parents and subsequent Fusarium presence on silks and seed infection/contamination.


Ascospore Trapping of Sclerotinia sclerotiorum in Snap Bean Fields and Root Rot Management (2011)

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


Root Rot of Sweet Corn in the Willamette Valley

Root rot of sweet corn is an important disease of sweet corn in the Willamette Valley of Oregon, first diagnosed in the 1990's.  Root rot is caused by a disease complex including Pythium arrhenomanes, Phoma terrestris, and Drechslera spp. Severe root rot was shown to reduce yield in Golden Jubilee by as much as 3 T/A and Super Sweet Jubilee by 1.5 T/A. Root rot also impacts crop quality by reducing ear fill and dimpling corn kernels.

Impact of Biological Control on White Mold Sclerotial Survival and Disease Severity in Subsequent Resistant and Susceptible Bean Crops


To evaluate the impact of Contans applications and reduced tillage on:
1) sclerotial survival,
2) sclerotial colonization by Coniothyrium minitans and other fungi,
3) apothecia production in the field in subsequent years, and
4) disease incidence in subsequent susceptible and moderately resistant bean crops.

Cultivar Evaluation for Control of Common Smut in Sweet Corn in the Columbia Basin (2010)

Twenty-two sweet corn cultivars were evaluated for resistance to natural infection by common smut. Four cultivars (Jubilee, Krispy King, Summer Sweet 610, and Supersweet Jubilee) have been included in all 12 years of these evaluations to gauge the relative severity of smut pressure over that time and in each trial season.