Good News for Almond Growers Whose Trees May be Subjected to Bacterial Blast
“Bacterial blast is a bacterial disease caused by the ubiquitous epiphytic bacteria growing over the surface of the trees,” said Adaskaveg. “The main pathogen is pseudomonas syringae. There's other pathavars, but they're minor compared to that particular one that we find on almond trees all over California.”
Because its living on the tree. It takes advantage when the tree is under stress. And when you get frost conditions during bloom, this is a very stressful condition cause you can get injury from the frost and then these bacteria are just hanging out there, they become aggressive and move into that injured tissue causing what we call blast, which is wilt of the flower and diseased and blackening of the flower parts. And then it keep growing and gets right into the loses.
Again, a solution may be available soon. Ask your PCA about a preventive pre-frost spray of Kasugamycin.