I have a question regarding Blackrot in grapes. I have a place in Upstate NY, near Glens Falls, NY. Its zone 5 technically, but we were zone 4 until a few years ago. It gets very cold. I used to get some great grapes from my Concord, and Concord Seedless. However, once Blackrot took over, they never produced again. While not totally against spraying, I would prefer to replant with Blackrot resistant grape cultivars. I have a Mars that should start producing this year, and planted an Everest last year. Trying a Somerset Seedless this year as well. Its my goal to put in many varieties and let them duke it out. From my research, there were some interesting varieties a very long time ago that were created by Munson. He was American and basically saved the french grape industry with his work. That said, he was working with crossing the grape cultivars with the many wild species , in order to develop disease free lines.
Outside of that, Im trying to find varieties that have worked for anyone. Im ordering a Sunbelt in a few weeks and really want to hear if anyone has been able to find a variety that doesnt need any spraying . I really want seedless, but that may be a little pie in the sky.
My experience with blackrot was challenging at first but I will tell you what i did. I grow seedless concord, seeded concord (both have seeds here) mars , catawba. I completed eradicated blackrot many years ago.and it never came back. I sprayed a combination of fungicides alternating every spray between immunox and captain. I trimmed the grapes back re moving all diseased canes. After 2 years of spraying I never saw blackrot again or had any need to spray grapes again. Red Candice and others attract blackrot getting the disease easily.
Hi Clarkinks. I had read your previous post regarding the alternating sprays. I do trim back, open up the plants, and clean up the ground every year. I have done light spray, but that didnt work. I will try what you have done this summer, but will also try to put in hardy resistant varieties. Hoping someone has had success with one. The problem Im having picking a variety is that when I find a Blackrot resistant variety, each supplier lists a different hardiness zone. Im technically in 5a, but many of them are zone 6, unless you go to another website , and they may say 4. So I am going to try the confusing ones as well. Have nothing to lose but a few bucks.
Regular spraying with a fungicide is key to controlling and eliminating blackrot. The other thing is variety, concord and other tried and true varities are fantastic grapes. All the fancy non juice grapes im going to pass on. You can see the issues are gone quickly. Like any disease with blackrot you should spray it and eliminate it then don’t spray unless you need to. Most pears and grapes i grow spray free now and have for years but the second I see a disease I eliminate completely if I can. Some pears such as fireblight susceptible types need a spray of copper every year. Cherries cannot be grown here without a fungicide sprayed a few times a year. .
If you do use captan and immunox i would recommend protective wear eg. eye protection and gloves.
We don’t have Blackrot in the Puget Sound lowlands, but generally
for all fungus problems
good air circulation
not crowding vines
are all important issues.
Perhaps a higher trellis
Plant grapes with a looser cluster.
Where I am in the Northeast, Black Rot is everywhere. Even if I am able to get rid of it, I cant see it staying away for long. There is a lot of work going on to come up with cultivars that dont get it. The trick is to be able to find them and not have to wait 15 years. Its unfortunate that most retailers stick to the old varieties and dont take the time to actually research their products for their customers. Knowing this, it would almost be faster to start hybridizing your own varieties and you would probably still end up ahead.
We do have a lot of botrytis
especially on tight clustered grapes.
our fall weather gets wet too soon.
So I broke down and have sprayed on a schedule with Immunox. The bloom this year was over the top, so I decided I would take a chance and use a fungicide. They look great so Im guessing it will control the Black Rot. Still looking for varieties that resist it, but I am trying the spray route. If it works, there will literally be bushels of grapes. I will post pics if its successful.
I give my grapes one spray of Immunox per year. Usually that controls it but some years I need another spray. I just was looking earlier today and I don’t see any black rot at all at this point so I am holding off on the second spray.