[Apple-Crop] Jonagold

[David Doud]

Thank you for this, Glen - it is new information to me - I have been twiddling my thumbs waiting for color here, not only on Jonagold, but on all the later varieties - tonight will be the first night of the season in the lower 40’s/upper30’s - hope that we’ll see some color development soon - 
David Doud IN


> On Oct 13, 2016, at 12:10 AM, Glen Koehler <glen.koehler at maine.edu> wrote:
> 
> Hi Art
>     A contributing factor to problems with fruit color this fall has been late arrival of minimum temperatures below 42F,   A "rule of thumb" from a Cornell bulletin is that optimum coloring conditions require two days with low temperature below 42F, followed by a day with high temperature over 68F AND over 80% sunlight on that day.  
> 
>      The Ag-Radar estimate for Sanford 9 miles away from you (far enough that I wish we had closer data site, working on that) shows that the two days below 42F requirement was not met until September 26, and Sept. 27 had a high temperature over 68F.  But the requirement for a day with high temperature over 68F AND over 80% sunshine was not met until October 6.
> 
>     I don't see this formula as a powerful predictor, esp. since I've seen some good color improvement while checking traps and doing fall scab index over the past few weeks.   And even if it was a robust predictor, it wasn't based on Jonagold.  Still it gives some numbers to possibly help explain late coloring conditions this fall.
> 
>     Easy to suspect the drought as a contributing factor.  I'm also wondering if you used ReTain on these Jonagold.  If so, do you think that had any effect on coloring?
> 
> - Glen
> 
> Glen Koehler
> University of Maine Cooperative Extension
> Pest Management Office
> Voice:  Office 207-581-3882,   Cell  207-485-0918
> 491 College Avenue, Orono, ME  04473
> UMaine Apple IPM <https://extension.umaine.edu/ipm/programs/apple/>
> Ag-Radar <https://extension.umaine.edu/ipm/ag-radar-apple-sites/>
> On Wed, Oct 12, 2016 at 2:19 PM, kellyorchards <kellyorchards at gmail.com <mailto:kellyorchards at gmail.com>> wrote:
> Why are my Jonagolds not coloring?  Can this be an issue if they have a heavy crop?
> 
> 
> 
> Art Kelly
> Kelly Orchards
> Acton, Maine
> 
> _______________________________________________
> apple-crop mailing list
> apple-crop at virtualorchard.com <mailto:apple-crop at virtualorchard.com>
> http://virtualorchard.com/mailman/listinfo/apple-crop <http://virtualorchard.com/mailman/listinfo/apple-crop>
> 
> 
> _______________________________________________
> apple-crop mailing list
> apple-crop at virtualorchard.com
> http://virtualorchard.com/mailman/listinfo/apple-crop

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://virtualorchard.com/pipermail/apple-crop/attachments/20161013/f33597ed/attachment.html>