Over the past couple weeks there have been many questions on fungal diseases that are impacting the quality of soybean pods and seed. An article came out from Purdue titled, “Fungal Diseases that Can Impact Soybean Pod and Seed Quality,” that did a great job outlining some of these diseases. Here are some beneficial bits from the article that we can use while examining our soybean seed quality this year.
Some of the most common fungal diseases we see are, Phomopsis seed decay, Cercospora purple seed stain, Frogeye leaf spot on seed, Athracnose and Downy mildew.
Characteristics & Management Options for Fungal Diseases
Anthracnose: Pod symptoms include: irregular shaped brown areas and small black fruiting bodies that produce spine-like structures. Seed symptoms include: Irregular gray areas with black specks. The management options available are crop rotation, tillage and foliar fungicides.
Cercospora Blight/ Purple Seed Stain: Pod symptoms: dark lesions. Seed Symptoms: pink to dark purple discoloration of seed coat. Some management practices could include tillage, crop rotation and foliar for the leaf blight stage.
Frogeye: Pod symptoms are circular to oval lesions that are red- brown to black. Seed symptoms include reddish-brown lesions often on the ends of the seed. To mange consider seed treatment and foliar options.
Downy Mildew: There are no external symptoms on the pod, but there is an internal white fluffy mass. The seed symptoms will be smaller and lighter, a crusty fungal growth on the seed and they will be dull and white in appearance. Try crop rotation and tillage for management.
Phomopsis: There will be black fungal specks on the pod and the seed will be shriveled and chalky white in appearance. The earlier in maturity it is, the greater risk for resistance.
Why Prevent These Diseases?
Disease infected seed equals:
- reduced storability
- decreased germination
- loss of seed weight and reduced meal and oil quality
Limit Fungal Growth By…
- Keep seed free from fungi or other pests
- Clean seed without organic or other waste material
- Store in less than 2% moisture
- Cool and uniform storage temp
Use resistant varieties when you can. Use seed treatments that help reduce seed to seedling disease transfer. Foliar fungicides can help reduce risk to the pod. Tillage and crop rotation.
We are hoping everyone continues to have a safe and successful harvest. For more questions on fungal diseases or seed quality, please contact one of our Associate Partners. To read the full article from Purdue, click here. As always, please follow us on social media!