Perennial grower for a large-scale, wholesale nursery here. Not sure if this is the best place to ask, but this one is stumping me. So we grow a variegated Solomon's Seal at my job, planted from bare rhizomes. Every planting, this seems to happen, especially when it's extra rainy, which I know is the root cause. The plants just pop off from the rhizome underneath the soil, usually they overwinter okay though.
Does anyone know what this white mold is? My boss said these have anthracnose, which can apparently also be systemic. Could this be a secondary infection? Also – any suggestions on how to treat it? I did a fungicide drench with Subdue Maxx (MOA 4), Segovis (MOA U15), and Okestra Intrinsic (MOA 7/11), but I'm not sure it will treat sufficiently. I believe I used Segway O (MOA 21) on them last year, which seems to work when non-systemic treatment is needed in the root zone. I'm in a warm, humid climate in Southern Pennsylvania for reference, so there only so much I can do with cultural practices (irrigation, spacing, or overwatering).
by the_porta_party
1 Comment
That seems to be Sclerotinia, white mold and antracnose. The wet and hot climate suggests that this is a favorable environment for this to develop.
If that is confirmed you should destroy the plants and use solarization for the soil, go easy with the water and increase the space between plants.
Don’t forget to rotate different fungicides, different mechanisms of action.
You also could rotate between crops with grasses.