Forcing dormancy - removing leaves after harvest?

Hi all,

My orchard is in Z5b in NY. I face the same problem each fall as it relates to getting the dormant fall sprays on.

I have different varieties ( apples, pears, plums, apricots nects etc.) and obviously they all , even within the same fruit, lose their leaves at different times.

My problem is that I can only get to do the spraying on weekends and time and time again I wind up waiting too long for all/most trees to go dormant and then one weekend of bad ( and cold) weather throws everything off.

I am trying to enlarge the window within which to be able to get my spraying done and I was wondering if stripping the leaves manually will act to hasten the trees dormancy. AND if the answer is YES, then when would be a good time to start in Z5b.

Thanx

Mike

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In my opinion I would not strip leaves to force dormancy so that I could do a dormant fall spray. At this point in the season the leaves that are green are photosynthesizing and that energy is going to the roots to jump start the tree next spring.

Once the leaves are brown even if they are hanging on the tree I dont see any reason you couldnt spray then. What do you plan to spray, chemical wise?

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No doubt the right answer. Trees that do drop and you’re able to spray you can flag that they’ve been sprayed. This article tells you everything you need to know about applying dormant oil alone or as a dual fungicide treatment: Dormant Oil & Mixes of Fungicide Temperatures What’s important to glean is that lime sulfur should not be mixed with dormant oil. They should be separate applications at least a week apart. Mixing oils with copper or other fungicides isn’t a problem.

The article also states that oils and fungicides may be sprayed anytime the temps are above freezing and will be for at least 24-hours after. So you have a window that lasts and lasts and lasts… and if you don’t accomplish everything this fall due to weather, you simply wait for any time during winter where temperatures are above freezing.

Dax

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@TurkeyCreekTrees
@Barkslip

I am thinking more of stripping at the end of October to mid-November.

Keep in mind that I only get to the orchard on weekends (130 mile one-way trip). I usually “winterize” two weeks before Christmas and generally I tried spraying the weekend after Thanksgiving. This has proven to be too short a window to avoid weather issues.

I was thinking of stripping sometime at the end of October to mid-November.

Once the place is winterized going up mid-winter is problematic as there is no heat or water and I have removed all the chems to the garage in the permanent residence to keep them from freezing over the winter.

Maybe the question I need to ask is…
How “dormant” do the trees need to be in the fall in order to be “dormant” sprayed?

Mike

I think that’s the correct question, yes.

Dormant oils may be sprayed year long just so the temperatures are under 80 F. Therefore, leave the leaves on and begin spraying.

Dax

Why do you even bother to spray your trees in fall? I never do. Time to take a break, let the trees take care of removing their leaves. .

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@alan

I was under the impression that fall dormant spray is the first half of pear psylla regimen as well as zapping any other insctoids that are still around setting up for the winter .

Mike

I’ve never heard of controlling psyla with a fall app. Only controlling peach leaf curl when early spring isn’t adequate. Even for that, early spring has always worked for me.

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@alan

Alan, I think you just saved me much time and travail.

I am not plagued by leaf curl.

You are close enough to me that what works for you should work for me.

I will, however, be more meticulous and focused on getting the spring sprays done right.

Thanx
Mike

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You can find commercial fruit production guidelines created by Cornell free on-line through U.Mass. This is my primary source for this type of info, combined with my experience. There is quite a bit of info on psyla, but no mentions of fall apps.

I’m still trying to figure out what the cause was of pear defoliation this year. Usually it is psyla, but that usually starts on the growing shoots and then leads to total defoliation when fabracea moves in. This year, leaves remained on growing shoots of defoliated trees.

I like to use Lime-sulfur in the fall to kill aphid/scale eggs. I mix it in oil. Since I started doing this I have not seen an aphid or scale on my stone fruit ever. Before, they were there, not anymore.