Disease and related disorder management

Liming and clubroot control in brassicas- handout for 2013 Veg Field Day

Clubroot is becoming an increasing problem on Willamette Valley vegetable farms. Most cultivated brassica crops (broccoli, cauliflower, cabbage, etc.) are highly susceptible to the disease, which is caused by the soilborne fungus Plasmodiophora brassicae. In severe cases it can cause significant crop losses, and heavily infested fields may be taken out of production. Once a field is infected, eliminating the pathogen is difficult if not impossible because its thick walled resting spores have been shown to remain viable in soil for up to 18 years. As a result, once pathogen populations have developed to economically damaging levels, the goal of the farmer is to manage rather than eradicate the disease. One effective control strategy is to raise the soil pH to ≥7.2 through liming.

What is Contans and how can it be used in western Oregon to control white mold?

Contans™ is a biological fungicide registered for post-harvest use on snap beans and other crops and approved for use in organic production systems. Coniothyrium minitans (C. minitans) is the fungal biocontrol agent in the product Contans™ (Coniothyrium minitans strain CON/M/91-08, active ingredient of biocontrol product Contans® WG, SipCamAdvan LLC, Roswell, GA).

Sweet corn diseases and their management in the PNW: Seed treatments and development of Fusarium-free seed

Principal Investigator: Cynthia M. Ocamb, Ext. Specialist & Associate Professor
Botany and Plant Pathology, OSU – Corvallis
e-mail: ocambc@science.oregonstate.edu

Collaborator: James R. Myers, Horticulture, OSU – Corvallis


1. Conduct an evaluation of materials currently registered on sweet corn for control of seed rot and seedling blight.

Gray and White Mold in Snap Beans

A number of growers and agricultural professionals have asked me whether we are seeing resistance to mold in snap beans to our currently registered fungicides. The short answer is, not to my knowledge. In a normal year, the primarily threat to snap beans is white mold (Sclerotinia sclerotiorum). When we have a cool, wet spring, we see both white mold and gray mold (Botrytis cinerea). Gray mold is a game changer. Gray mold control requires a tank mix, early timing, and a two spray program.