appleman said:
Bill I didn't do a dormant spray this year. I really didn't have much disease last year, just a few spots. I probably should go with a dormant oil, but haven't used it to date. I mention disease because it is ever present in the environment. Without diligent preventative sprays it is likely that we get disease manifesting in one form or another. The rains compound the problem because each inch of rain you get, the spray residue is halved. This reduces the effectiveness of the spray in disease prevention.
Tuesday we had visitors at the Willsboro Farm. A bunch of the personel from the Hort Department were visiting area orchards and farms. We were on their stops. Many interesting folks were there and they all were looking for any pests they could find- be it insect or disease. They all had their little magnifying glasses and using them. I had the pleasure of meeting Dr. Julie Carroll from Cornell. She is a plant pathology specialist. We talked a bit about spraying with all the rain pressure we have had. We all hid out in the greenhouse for a while- during a downpour, then went over to the vineyard. After they all left at about 6:30 PM, I went back to work and sprayed the grapes. It remained fairly dry overnight to give the spray a chance to dry on.
How are your vines doing? Did the goo ever go away?
Rich - Thanks for asking.
It is interesting that I did two dormant sprays, one at Thanksgiving and the other in early April, using a mix of a commercial lime-sulfur product with one percent Stylet Oil added per Gregorio's recommendation on the other forum. I applied the April spray just after the initial long pruning. If I understood Greg correctly, the combination seems to knock down overwintering very PM well for him, so I gave it a try since I ended up with some wicked PM on my Foch and Frontenac by the end of the season last year. This spring I have sprayed twice with SO at two week intervals.
As I wrote earlier on this forum, the pruning cuts on my vines kept running sap endlessly and the orange goo quickly developed wherever the sap ran. At this point in the growing season I am dismayed to see that almost none of the vines were doing well, except two and a half of my three St. Pepins.
Looking at this objectively, whatever got the dormant spray mixture followed by the two SO applications appears to be struggling. The two vigorous St. Pepins were not sprayed with SO once green growth started. The third had one cordon arm sprayed while the other arm was not sprayed. The arm I sprayed is adjacent to the Foch and I wondered if the proximity might argue for some spray protection, although I have never seen evidence of PM on the St. Pepins over the last two years. That arm has nowhere near as vigorous growth as the unsprayed arm.
I am left to wonder whether the dormant spray application was harmful in and of itself on the cold hardy varieties, in some way short circuiting the vines ability to heal pruning cuts. I also have to question the safety of Stylet Oil (mixed at about 1.5 percent) for green growth, based upon the reaction of the third St. Pepin vine and of course all the other varieties.
One other consideration would be my sprayer itself. Although I try to clean it out thoroughly after using it, there might have been a trace of lime-sulfur left when I mixed the SO solution for my first two sprays of the season. This is an unknown, and I could buy a second sprayer so I don't have the possibility of crossover mixing.
It is very disheartening to see most of my vines set back so badly. In the case of the 5 Landot Noir, there is barely any growth at all, mostly barren nodes and what small growth there is is shriveled from the orange goo.
So, maybe it is too early to declare this a learning experience since I have no answers to these phenomena. If you or anyone else has any insight or similar experience I'd sure like to hear about it. I am letting new growth come up from the ground where it is happening at many of the vines, and will replace whole trunks and cordons where necessary.
