how long can maple be "dormant" without changes to chemical make-up of sap?

[bowtie]

curious as to if there are is a general rule or any evidence of prolonged dormancy of sap production will cause a chemical change in the sap once production resumes. will these periods of extended dormancy "trick" or fool trees into metabolic changes in the sap. as alot of you are experiencing, i have not had a run on most of my trees in over 2 weeks and worry that it will have an affect on the quality or viablity of the sap to produce quality or sellable maple product:ie low sugar content or metabolic flavor. would like some input from the experts in particular dr.tim.

[DrTimPerkins]

What you are referring to as "dormancy" is not what is considered true dormancy by tree physiologists. What we have had recently with the cold weather is simply stasis. Not much happening during that time. Sap chemistry doesn't really change. There is very little metabolic activity in the tree, and only slight microbial activity in tapholes.

[bowtie]

thank you dr.perkins. i am always trying to learn more about about the science of maple syrup production, and appreciate the info from you and fellow mapletraders.

[happy thoughts]

Thanks Dr Tim. Stasis is going to be my new 4 letter word! I'm still hoping to salvage this season and ran across the following in an old copy of the Maple Producer's Manual. It gave me some hope, lol, now that the trees are finally running during what would normally be almost the end of the season here.


The greatest yield of sap may be produced in a single run that occurs at the beginning of the period, at any time during the period, or at the
end of the period. In 1960 almost all the sap crop was collected in a 24- to 48-hour period and the Brix value of the sap was much higher than
2.2°. Many producers reported sap of 5° Brix and higher.

Have you heard of this? If so, any idea what made 1960 sap flow so unusual? Were the trees also in prolonged stasis or did this occur earlier in the season? Thanks

[DrTimPerkins]

If so, any idea what made 1960 sap flow so unusual?

You'll have to ask someone a bit older than I am about that particular year. However a good portion of the entire production for a season can occur in just a few good sap runs. A complete season may be only 5-15 runs in total, and perhaps only a handful of those will be really good (especially on gravity systems).

[PerryW]

for some anecdotal evidence....

I made 29 gallons of Fancy before the freeze-up. I let the contents of the pans freeze solid and they sat there for 14 days until I finally got enough sap to start boiling last monday. There was never any drop of grade when i resumed boiling. I'm up to 57 gallons now and the syrup is as light as I've ever seen it.

[unc23win]

We are making very light syrup and have been all year. It has only darkened slightly since the very first boil, so light you have to look VERY close to see the change. In a normal season for us the syrup will be light and get a lot darker towards the end. If thats the case the end is not that close yet. The 10 day forecast is all freezing nights.