Something is rotten in the state of Blue-Merle Country. A greenish, blackish moldy substance, which I might be pleased to see in blue cheese or a penicillin petri dish, is growing on the vines right where the woolly cotton buds are bulging in preparation of sending forth new shoots. I'm wondering if this is good stuff or bad stuff and in the worst case what impact this might have on the grapes and how am I ever going to control it?
It so happened that a county agricultural inspector was out our way and I asked her about it. She said all the rain and moisture we've been having has encouraged fungus to grow (which makes sense because this is the wettest I've seen it in the 3 years since we planted the vines). We've had 13.7" of rain season to date, with more on the way later this month. Her thought was once the weather warmed up the fungus would dry and fade away. (If only it were that easy.)
I took a picture of the growth and sent it to Pete Anderson, a vine expert in San Diego and always willing to offer advice. Here's what he said:
"There are three types of fungi that invade our vines: uncinula necator (powdery mildew); aspergillus niger (black fungus); penicillium (green or blue fungus). I have all three in my small vineyard. Treat it like powdery mildew; use the oil to eradicate."
I wonder if Pete brought us the penicillium during his last visit? Well, now that the county inspector has paid us a visit it's legal for us to purchase and use organic stylet oil to try and control it. I'm also thinking about pumping milk from some neighboring goats to make cheese.