You can see this paper "Fungicide Sensitivity and Characterization of Cobweb Disease on a Pleurotus eryngii Mushroom Crop Caused by Cladobotryum mycophilum"
If you don't find a suitable rate, You may apply a scale/rate similar to the disease you work on or try to collaborate with researchers listed in the article, make one from your experience
Also Pls. find the attached files with its references