dormant oil/sulphur versus copper spray on grapes?
I heard a grapevine specialist a while back on radio who recommended spraying either copper or dormant oil/lime sulphur on grapes to prevent some type of early season disease which results in lower fruit production, can't recall specifics, and I dont see dormant oil/lime sulphur in the instructions for whether to use on grapes.
-Was it a lower strength mixture of one of these he was recommending, to be used after buds opened or what do others use?
Here it's lime sulphur/dormant oil spray time of year again, which is said not to prevent against canker on apple trees, ie my transparent yellow. Instead recommmended is copper spray although have heard copper spray can slow down the growth of the plant or its fruit.
-Any thoughts, is this well documented?
-Anyone know the amount of time required between spraying lime sulphur/dormant oil and copper spray on trees?