This long-standing tenet is all about
russeting for which there are many riffs. I'm glad you brought this concern to the fore, Joanne, as it would be good to hear a range of actual experience in this thread.
Way back, it was noted that a petroleum-based dormant oil followed by sulfur within 30 days increased russeting. That set an impossible stage for a fledgling grower like myself in the early 90s . . . and soon I would come to question many aspects of
conventional organics. Truth is sulfur alone can cause russeting. Same for fixed copper (which incidentally is applied with oil to help spread mineral particles) when used much beyond green tip. Same for copper soaps if conditions go awry. Same for "biological fats" in a straight up holistic program, primarily neem oil. Much depends on the cultivar and temperature. One thing worth pondering is how bad is a degree of russeting of fruit skin in order to check disease pressure? John Bunker of Fedco Trees has told me about studies showing that fruit brix goes up under russeting . . . thereby flipping this conversation entirely on its head.
Transition scenarios and drawn out cloudy weather can call for a mix of thoughtful approaches. Playing the sulfur card for big wetting events while at the same time keeping up plant immune function and competitive colonization with holistic sprays is a reasonable course of action in my opinion. Those health-focused apps are timed ideally to boost phytochemistry while the sun still shines (a day if not two before grayer weather moves in). Now say a rainy period begins. Are you trying to use sulfur proactively as well, before the leaves get wet? Or are you timing the allopathic app to acidify moisture puddles on the leaf midway? Who's done what? And most importantly, how was the
fruit finish come harvest?
Lost Nation OrchardZone 4b in New Hampshire
Edited 1 time(s). Last edit at 04/05/2017 11:43PM by Michael Phillips.