Disease and related disorder management

Andrews, N. and B. Baker, 2009. Can I Use This Input on My Organic Farm?. eOrganic article. Available at http://www.extension.org/article/18321.

Funding was used to establish, evaluate, and analyze data from sweet corn field plots established on the Jim Belden farm near Stayton. Twenty hybrids with se or su endosperm were evaluated for resistance to root/crown rot. Ears were also evaluated for processing quality.

Objectives:

• Characterize su and se sweet corn hybrids for reaction to root/crown rot. 

Cooperator: M. Powelson, Botany and Plant Pathology

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.

OBJECTIVES:

The cause(s) of the root/crown rot problem of sweet corn in the Willamette Valley the past 10 years has been a challenge to identify. Root rot is the precursor to crown rot symptoms. Many species of Fusaria and Pythium have been isolated from symptomatic roots and crowns.
Experiments were conducted in the field and greenhouse in 1998 to help pinpoint the pathogenic agent of corn root rot and to evaluate the efficacy of soil treatments on managing this disease.

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 the 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 symptom can be alleviated or the infection inhibited.

OBJECTIVES:

Objectives:

For the past several years a "stalk rot" disease has been afflicting commercial sweet corn fields grown in the Willamette Valley. The disease seems to have a pathogenic basis, but the exact causal agent is unknown.
Eighteen hybrids with se or su endosperm were evaluated for resistance to root/crown rot. Ears were also evaluated for processing quality.

Objectives: Characterize su and se sweet corn hybrids for reaction to root/crown rot.

Cooperator: M. Powelson, Botany and Plant Pathology

Objectives:

The cause of sweet corn root rot has been difficult to determine. Extensive sampling and surveying indicate the fungal pathogens Pythium arrhenomanes and Fusarium oxysporum and solani are consistantly associated with diseased roots.

Experiments were conducted during 1999 to determine: 1) if the cause of root rot of sweet corn is biotic, 2) if the disease is associated with plant nutrition, and 3) the potential role of stress in disease development and 4) the effect of soil treatments on reducing severity of root rot symptoms.

COOPERATOR:

Report to the Oregon Processed Vegetable Commission

Philip Hamm George Clough, and Mike Baune
OSU Hermiston Agricultrual Research and Extension Center

Lindsey du Toit and Lois Carris
Washington State University

Objectives: