grape vine dry mold
have a couple vines that are very healthy and get very good sun throughout the summer here in no cal. they are around 10 years old and are trimmed back every year to the standard T type stock with the bases around 2.5". the 1st couple years with grape production they were a very good table grape. about 6 years ago i started to experience a dry type black mold on the fruit and new growth stocks every year. ive had to throw out 30-40 lbs of grapes every year!
i have tried spraying with copper & sulfur based products in an effort to get a handle on it. would spray a few times during winter, then every week or so as the growth started in the spring to no avail. this year a nursey staffer suggested to put in the soil and water in. i have done so with about a 1/4 cup of sulfur in the drip zone of each vine twice since march. a couple other facts-- they are near lawn and a juniper. other suggestions would be appreciated. thank you in advance juan.