Dormant oil spraying - timing, etc

bhouston

Senior Member
Thread starter #1
So, its about time for dormant oil application in Johnson county. I have 50 or 60 apples, pears crabapples and persimmons. Because of the wierd weather my trees are blooming since mid february.

Does it hurt the tree by spraying dormant oil and getting it on the blooms..?? Should I spray and be sure to avoid getting it on the blooms...?Or, skip it altogether..?? Any thoughts are much appreciated.
 
#4
Depends on the oil. More modern "lighter" oils can be sprayed, even in the summer.

Know this isn't want to hear, but read the label.

I have been late and sprayed just as the leaves were coming out and got some minor leaf burn that didn't seem to have any permanent effect. Temp has a lot to do with it. Used the newer products later with no problem. One they begin to bloom I don't use anything but fungicide and sulfur until the fruit has set.
 
#6
I guess my question would be, having missed the window when “dormant spraying” would be of benefit, why do you want to?

Do you have a lot of problems with scale, or other pathogens dormant oil gets?

If not, skip it. As Doomtrpr said, sun + oil is a recipe for scorch. Down here, my pears popped with the week of fake spring, but the apples (other than native crabs) are just budding.

I would not do the dormant oil, but instead get my rig ready for streptomycin for fire blight; last year was the worst I can recall; so if we get rain there will be plenty of inoculum this year too. Next year plan to do your dormant spray the first week of Feb if you get a demonstrable benefit from it.
 

bhouston

Senior Member
Thread starter #7
Thinking I will skip this year.....

Thanks for the thoughts - not worth the risk.

Next question, when do I spray for fire blight..?? That was my biggest problem last year - lost 5 trees to fire blight. As usual - this is my "go to" place for real advice and info.
 
#8
Thanks for the thoughts - not worth the risk.

Next question, when do I spray for fire blight..?? That was my biggest problem last year - lost 5 trees to fire blight. As usual - this is my "go to" place for real advice and info.
All the time.

I gave up on non--blight resistant varieties. I know you are supposed to be able to control it but the effort was not worth the results.

IMO the typical humid summer conditions in GA make it virtually impossible to control. The problem is that once you "control" it, the trees are constantly getting re-infected.
 
#10
but instead get my rig ready for streptomycin for fire blight; last year was the worst I can recall; so if we get rain there will be plenty of inoculum this year too.

Do you have a good source for the streptomycin?
The last I bought I think I got from Johnson's Nursery, which has since gone out of business.

Look on the net for Ferti-lome Fire Blight spray:

https://www.starkbros.com/products/...disease-controls/ferti-lome-fire-blight-spray

or Agri-mycin:

https://www.agriculturesolutions.com/agri-mycin-17-streptomycin-for-fire-blight-2-lb

As to the question above (when to spray); your first spray is when trees begin to have flower buds (called 1st pink); then weekly, until they finish flowering. I never have time for that for deer orchard trees; for them using "resistant" varieties & pruning in winter generally is about the best option. But if you have time to spray, the most important time is during bloom, as the disease is primarily spread tree to tree by bees. Once the tree is infected, sprays do not help.

https://extension.psu.edu/disease-update-the-fire-blight-saga-continues

http://msue.anr.msu.edu/news/three_antibiotics_available_for_fire_blight_management_during_bloom
 
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