Fall precipitation and sap production question.

[SDdave]

I was wondering how influential fall precipitation is to sap production, both quantity and sugar content. I suppose they are both linked, qty. and % sugar. But does a drought in the fall mean less sap production in the spring? And vice versa with extremly wet condtions in the fall? Really curious about it. We're a little dry around here, having only an inch or so of precip. since October.

SDdave

[SDdave]

Edit...less than 2" of precip. since June 22nd. Dr. Tim please answer...no one else dares.:)

[DrTimPerkins]

I was wondering how influential fall precipitation is to sap production, both quantity and sugar content. I suppose they are both linked, qty. and % sugar. But does a drought in the fall mean less sap production in the spring? And vice versa with extremly wet condtions in the fall? Really curious about it. We're a little dry around here, having only an inch or so of precip. since October.

Probably not a lot of influence in the short-term until it begins to impact tree health. As long as there was adequate rain during the growing season, the trees produced sugar. In terms of moisture, the important time is the spring. If there isn't good soil moisture, trees can't take up water during the freeze cycle, meaning there won't be much coming out during the thaw (exudation) period.

[flooder]

its not that no one else dares,it's that people get sick of answering the same questions over and over again

[SDdave]

First thank you Dr. Perkins for that information, it answered my question perfectly.



its not that no one else dares,it's that people get sick of answering the same questions over and over again
Secondly, where on this site is there another ? about drought and sap production without the terms "I think". I do a search each time before I post a new thread. Yes I agree with you there are a lot of same ? over and over again, but not for this subject, alot ( and I mean alot) with the inverse. I am sorry I posted this thread now. I was going to have to gather data from various parts of the country, cross reference annual rainfall and sap production.

Nothing personal Flooder, not only did I wake up on the wrong side of the bed, but I don't feel the need for a reply like that.

SDdave

[FameFlower]

[QUOTE=DrTimPerkins;170975]....until it begins to impact tree health.[QUOTE]

How do you know when it begins to impact tree health? ... what are they signs of sugarbush drought stress?... say there were drought stress, how much do you reduce tapping?

Where I am in East-Central Minnesota we had very little precipitation since the end of the summer. (Signs of it being so dry, we irrigated our veggies into October, I fed my bees (I HATE doing that) into December because the plants just were putting out nectar and have still had high mortality from not enough winter stores, I can break up the frozen soil in my sugarbush there is so little moisture in it, I'm dehydrated).

[DrTimPerkins]

Go outside in your sugarbush in the spring when the sap is (or should be) running. Sit down on the ground for 5 minutes. If your backside is wet when you stand up, there is ample moisture in the soil. The technical term for that is the "butt test" :lol:

Drought impacts tree health by reducing radial growth. In very severe instances, leaves may be somewhat stunted. If you get a severe drought, or 2-3 years of moderate drought, you can start seeing branch dieback. At that point, stop tapping those trees. Oftentimes people will notice that they have a hard time finding nice white wood when they tap, especially if they're still using 7/16" spouts. That's a good indicator of slow growth and/or overtapping. Let up for a bit, cut back on the number of taps, and if you can, don't tap the trees in that section for a few years then try again and see if it's gotten any better.

[SDdave]

Go outside in your sugarbush in the spring when the sap is (or should be) running. Sit down on the ground for 5 minutes. If your backside is wet when you stand up, there is ample moisture in the soil. The technical term for that is the "butt test" :lol:

Drought impacts tree health by reducing radial growth. In very severe instances, leaves may be somewhat stunted. If you get a severe drought, or 2-3 years of moderate drought, you can start seeing branch dieback. At that point, stop tapping those trees. Oftentimes people will notice that they have a hard time finding nice white wood when they tap, especially if they're still using 7/16" spouts. That's a good indicator of slow growth and/or overtapping. Let up for a bit, cut back on the number of taps, and if you can, don't tap the trees in that section for a few years then try again and see if it's gotten any better.

Dr. Perkins,

How long do you wait to start retapping these trees? We are definitely in our 2nd year of moderate drought (a little over 7" below normal this year), I have not noticed any branch die back yet, nor stunted leaves. But, the ground is definetly dry 4 to 5 foot down. I plan on taking this season off as of know, unless we get back to normal (highly unlikely).

Just curious,

SDdave

[red maples]

I thin my woods slowly basically as I need firewood for the house etc. and every year the canape fills back in reguardless of how heavy I thin (sounds funny) so even though we are behind in precip. the trees are still growing. We have had heavy rains here as of late but not soaking rains like we need mostly heavy stuff runs right off. just have to wait until you tap see what the weather brings and see what happens!!!

[DrTimPerkins]

How long do you wait to start retapping these trees?

There is not a lot of good science on this topic. Just wait and see what things look like in the spring.