Chris
I sprayed 3 times last year at 100PPM and had a huge outbreak of FB which just about wiped out my entire orchard. I was really worried about a carry over from all the bacteria last year. I cut out all the disease I could find and even dug out and burned the most infected trees. Also sprayed copper as late as possible which I believe helped.
100 PPM works for commercial folks spraying 400 GPA, but I had to up the rate slightly within the label guidelines to get the results I need. I also added Apogee to one of the strep sprays. According to a presentation I attended last fall, some growers add adjuvants like Regulaid or LI-700 which increase uptake of the strep buy 2 fold. I also learned that some marginal leaf chlorosis is a good indication of an effective dose. I’m concerned about possible resistance, but I’m a lot more concerned about FB killing my trees! The report was called "Fireblight Management Strategies in the Southeast, by K Yoder from VPI, but I can not locate the report on the Internet
Just went out and found more fireblight. Occurred in 23 hours time. Cut out 13 more strikes from the same tree. I have a feeling this may not end well. Hot weather and 60% chance of rain every day for the next week I think.
No other trees showing any effects at all including my very fireblight susceptible Red Bartlett.
Always something.
This is the first year I’ve experienced FB. It hit my Granny Smith tree - all on blossom tips. It continues as of today. I have Fuji, Red D, Jonagold that show no signs.
I’ve never spray for anything other than Codling Moths - guess next year I’ll spray copper during the dormant season.
Question: if there are no ling blossoms on the tree, does it do any good to spray streptomycin?
Thanks
FWIW letski, I never sprayed any copper or anything dormant at all before and this is the first year ever that I’ve had a FB strike. Now I’m definitely not saying they don’t work, I think they do, but they don’t guarantee anything.
This year I dormant sprayed heavily with copper, sulfur and chlorothalonil w/ oil late fall - early winter and again early spring.
I’ve never used it but based on it’s mode of action I’d suspect, and have read, that Strep is probably the best defense for preventing FB. It’s expensive though and as an antibiotic there are some issues at play and because of those things I’m avoiding it unless things here prove there is no way forward without it. I don’t think that will happen though, so no matter this year, next year I’ll do the same and go from there.
From the pros here and everything I’ve ever read it seems FB is kinda random about it’s appearance and even to some degree the varieties it seems to infect. As Scott said the other day though, eventually a pattern unfolds as to varietal infection rates. Next year you may have no issues or perhaps the granny is ok and the Fuji gets popped. That’s how I understand it anyway. Obviously avoiding susceptible varieties, or better yet choosing those which are resistant, is probably the best defense altogether, but again, no guarantees it seems.
Allow the pros to answer (don’t take my word for it), but there is conflicting information concerning this, but from what I gather, no, it seems it needs to be preemptively sprayed. I don’t know why that is though, being an antibiotic. It could be that it does work, but that spraying an active full blown infection could result in immediate resistance development for any that survive and mutate for resistance. I don’t really know, that’s just a guess on my part.
Appleseed - thank you for the response.
@Appleseed70, you are right that it needs to be preemptively sprayed, but you can get big fireblight problems well after the blossoms are all gone. This year the “big hit” period was completely post-bloom for me. I had about 100 tip strikes total which is more than the last 3-4 years combined.
yep…still getting strikes. Some, or maybe even most at this point are simply extensions of earlier strikes that I may not have cut back far enough to remove all infected tissue.
At this point I’m whacking anything that looks even remotely suspect since the tree has far too much foliage to begin with. As much as I’ve cut away though, looking at the tree you cannot even tell it.
Love this tree, it’s such a warrior, and a loyal heavy producing one at that.
My apples are starting to bloom. I had some fireblight last year, and pruned all that I saw out (including proximal portions of branch to ensure I got most out).
Is this early fireblight? Photo from my Hudson’s Golden Gem.
