Crop: Field peas
Downy mildew
Peronospora viciae
Recommended products: Mantle
Downy mildew is one of the most common diseases of peas, causing severe reduction in plant numbers as well as yield losses during cool wet seasons. It is most severe on young plants. Crops generally recover from infection during spring. As downy mildew affects the formation of the protective waxy coating on pea leaves, plants become more vulnerable to herbicide damage when infected.
The disease first appears on the lower leaves of the plant and then progresses upward. The underside of the leaves become covered with a fluffy grey spore mass; the tops of the leaves develop pale yellow-brown blotches directly over the spore masses. In severe infections, plants are a pale-yellowish green color, stunted and distorted. Flowers and pods may also become infected. Infected pods develop yellow-brown patches and may be deformed in appearance.
Life cycle
The downy mildew fungus over-summers in seeds, in the soil and on pea trash. Systemic and leaf infections of seedlings may occur from these sources. The infected seedlings then act as a reservoir of disease for surrounding plants.
Control
- Sow disease free seed
- Treat seed with a systemic seed treatment such as Mantle to protect the crop for up to six weeks
- Destroy all infected pea trash and practice wide rotations
