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-Original Message-
From: apple-crop [mailto:apple-crop-boun...@virtualorchard.com] On Behalf Of
Mark Angermayer
Sent: Sunday, September 10, 2017 11:38 PM
To: Apple-Crop discussion list <apple-crop@virtualorchard.com>
Subject: Re: [Apple-Crop] Timing of foliar nitrogen in peach
Thanks Harold and Jerry. Helpful information on timing.
Jerry, if you have time, could you clarify your comment, "Urea application on
peach in New Jersey have not been observed to be effective in increasing tissue
N in leaves buds and shoots. (Much research on this subject in Fruit Nutrition
by Childers and others)"?
Are you saying all the N absorbed through the leaves is translocated to the
roots, or that N is not absorbed through the leaves at all?I AM NOT REALLY
SURE BUT I THINK IT IS MORE OF THE LATTER. MAYBE IT WAS NOT ABSORBED BECAUSE IT
WAS THE WRONG FORM OF NITROGEN. MAYBE IT WAS BECAUSE THE FORMULATION OF UREA
DID TOO MUCH DAMAGE TO THE LEAVES RENDERING THEM LESS EFFECTIVE IN ABSORPTION.
I DID NOT READ ALL THE PAPERS ON THIS SUBJECT SO THERE MAY BE OTHER VARIABLES.
WHEN I STARTED MY CAREER I HAD THREE EXPERIENCED MENTORS AND ADVISORS. ERNIE
CHRIST, NORMAN F. CHILDERS AND ROY FLANNERY ALL DISTINGQUISHED PROFESSORS WHO
TOLD ME NOT TO WASTE MY TIME APPLYING FOLIAR NITROGEN INCLUDING UREA BECAUSE IT
WAS NOT EFFECTIVE IN SIGNIFICANTLY INCREASIN N LEVELS IN FOLIAGE AND FRUIT ON
PEACH. POSSIBLY TODAY THERE ARE BTTER FORMULATIONS OF N THAT ARE BETTER
ABSORBED IN FOLIAGE AS RPEORTED IN THE CALFORNIA INFORMATION. JERRY FRECON
on in the fall can delay bloom in peach, but can't remember where I read it.
Perhaps an article in a trade magazine. When I googled it, this is all I could
find.
"For example, the application of foliar nitrogen in the autumn delayed the
bloom of peaches compared to untreated controls (Reeder & Bowen, 1981). "
http://www.ccsenet.org/journal/index.php/jps/article/viewFile/52934/28326
Mark
On 9/10/17, Jerry Frecon <je...@acnursery.com> wrote:
> From Roger Duncan, Pomology Farm Advisor, UC Cooperative Extension,
> Stanislaus County "Fall can be an excellent time to apply certain
> nutrients if trees are deficient.
> Nitrogen. Nitrogen utilized by trees and vines for early season shoot
> and fruit growth comes from reserves stored in the roots and other
> woody tissues of the plant. This is why it is important to enter into
> dormancy with adequate nitrogen reserves. UC Extension pomologist
> Scott Johnson has shown that a low biuret urea foliar spray just prior
> to natural leaf senescence is an excellent method of supplying
> nitrogen to peach trees. At least 80% of the nitrogen is absorbed into
> the leaf within 24 hours. The nitrogen is then readily translocated
> out of the leaf and into long-term storage. Trees low in nitrogen
> because of nematodes, a high water table or other root problems should
> certainly benefit from this spray. This is also an excellent way to
> provide nitrogen without risk of ground water contamination.
> Each spray supplies about 50 pounds of actual N per acre. That means
> if a granular formulation of low biuret urea is used (which is almost
> 50% N), you need to apply about 100 pounds of product per acre. If a
> second application is necessary, it should be applied at least two
> weeks after the first application. Within a few days, you should start
> to see some burn along leaf margins and at the tips. Defoliation will
> probably progress a little more quickly than normal."
>
> Urea application on peach in New Jersey have not been observed to be
> effective in increasing tissue N in leaves buds and shoots. (Much research
> on this subject in Fruit Nutrition by Childers and others) If N tissue
> levels were increased as they are with N soil applications then N
> deficient peach trees may be healthier and more winter hardy, I am
> not aware of any research demonstrating a delay in bloom with urea foliar
> applications.
>
> Jerome L "Jerry" Frecon
> Professor Emeritus, Rutgers University And Horticultural Consultant
> for www:jerseypeaches.com www.acnursery.com
>
> -Original Message-
> From: apple-crop [mailto:apple-crop-boun...@virtualorchard.com] On
> Behalf Of Mark Angermayer
> Sent: Sunday, September 10, 2017 1:46 PM
> To: apple-crop@virtualorchard.com
> Subject: [Apple-Crop] Timing of foliar nitrogen in peach
>
> I've read foliar urea in fall can increase hardiness and delay bloom
> on peach.
>
> Can anyone tell me the optimum time to apply foliar urea (100 lbs./ac
> - i.e. 50 lbs. actual N) on peach? I'd like to use regular soil urea (vs.
> the low biuret) because of cost, but understand soil urea will burn
> the foliage.
>
> I don't want t
