Combine fungicide with fert.
 

When I fert. I use rain water in a sprayer. Can I combine a fungicide or pesticide with fert.

Giving your post a bump up. I have read that you can and that not to . I don't want to tell you wrong as I don't combine .. interested to see what others say ..:)

I do it whenever it's convenient - i.e. if I need both fertilizer and fungicide and I've never had a problem. I don't store rainwater though.

With stored rainwater, depending on the storage conditions, it might even be advantageous. If it's collected from a roof where nutrient buildup could be added to the water, you could theoretically have a little fungal bloom in your storage tank.