Yesterday, I whacked the weeds under and around the grape vines, for air circulation – and to prevent the weeds from competing with the grape vines for resources.
And then this morning, Jerie pruned the vines, removing ones with the black rot, pruning excess leaves, and making sure the growing clusters of grapes weren’t touching anything.
After that, I sprayed them all sides wet with Serenade. Which contains QST 713 strain of Bacillus subtilis.
This was for the black rot. Where the grapes get black dots, which quickly grow to consume the whole grape, leaving ugly black dried out dead grape in its place. Very contagious too. Vines with bad grapes get black streaks in them, I noticed today while spraying.
I think we got this early enough, this time. Most grape clusters are unaffected. The few infected clusters are at the stage where a few grapes have black dots.