Sap amount on 8-10 inch tree

[spud]

I was wondering if there has been any research on the amount of sap a smaller diameter sugar maple will give. One would assume a large maple with a big crown would give more sap then a 8-10 inch maple in the same woods during the same timeframe. Although this might not be accurate. I talked to a guy down the road that taps 6-8 inch trees only in his very young woods. He says that he got 15 gallons per tap last year on the little trees with vac. Does this sound right? Has anyone gotten similar numbers from small trees? Has anyone gotten more? Thanks

Spud

[adk1]

I will be watching this thread as at least half of my trees are in the 8-10 diameter range and are woods trees. Luckily they are all on a S/SE facing slope so should recieve good sun in the morning and for a long timeframe.
Having said that, I was looking at very old pics of a local producers grandfather. Although their maples now are 24"+, back then they were small in the 8-12" range and they had taps in them! You need to tap what you have is my motto. I am using 5/16" taps of course.

[DrTimPerkins]

I was wondering if there has been any research on the amount of sap a smaller diameter sugar maple will give. One would assume a large maple with a big crown would give more sap then a 8-10 inch maple in the same woods during the same timeframe. Although this might not be accurate. I talked to a guy down the road that taps 6-8 inch trees only in his very young woods. He says that he got 15 gallons per tap last year on the little trees with vac. Does this sound right?

Sap yield will depend upon several factors. If on gravity, a tree will produce far less sap than on vacuum, and more still on high vacuum, especially if good taphole/tubing sanitation practices are used. 15 gallons of sap from a 6-8" tree on vacuum is not unbelieveable....the better question.....should you be tapping 6-8" trees? Most tapping guidelines suggest first tapping at 9-10" minimum.

[spud]

Is it safe to say that he will kill those 6-8 inch trees if he keeps doing this every year? Everyone talks about the tap hole healing up fast on those little trees. Although i remember you ( Dr. Tim ) saying it is the internal wound that is the problem on these small trees. I was told the big operations in Canada tap 5 inch trees all day long. Thanks

Spud

[adk1]

Which brings up a good point I hope teh Dr. speask up about. What should the depth of taphole be in an 8" dia tree using 5/16" bit. I have heard mixed reviews. The NAMPM states taht on gravity, the amount of sap increases with depth up to about 2". At first, I was goign to tap up to that 2" mark, but am now thinking, that since a majority of my trees are in the 8-10" range, that I will set the depth to 1.5".

[spud]

I was thinking the same thing. I even was wondering if the 1/4 spout would be better on 8 inch trees?

Spud

[DrTimPerkins]

Is it safe to say that he will kill those 6-8 inch trees if he keeps doing this every year? Everyone talks about the tap hole healing up fast on those little trees. Although i remember you ( Dr. Tim ) saying it is the internal wound that is the problem on these small trees. I was told the big operations in Canada tap 5 inch trees all day long.

Will a taphole kill a healthy, rapidly growing 6-8" tree....no, most likely not. But it'll surely not help a 6-8" suppressed tree that is just hanging in there. In most cases you can do what you want....your land, your trees (unless you lease or are organic-certified). However tapping guidelines were developed for a reason.

So take that 5" diameter tree in Canada (or anywhere). You put in a taphole that is 2" deep. That is 2/5 (or more if you discount the bark) of the total diameter of the functional wood of the tree. The next year, you put another in on the opposite side. Now the tapholes you drilled (or the staining column) are 1" apart in the center of the tree. Keep doing that and eventually the ENTIRE center of the tree is stained, with all the staining columns having coalesced into one central column, and this zone is now completely NON-FUNCTIONAL for sap movement or sugar/starch storage any longer. So you have 10-20 yrs later, a 6-7" tree with 5-6" of the inside of the tree being non-functional from a standpoint of sap movement or sugar storage. So basically you've converted that tree from a 5" healthy tree that'll yield a reasonable amount of sap (for a period of time at least), into a 2-4" FUNCTIONAL diameter tree. You're headed in the wrong direction as far as the health and function of the tree goes. Now if you wait until that tree is the proper size to tap (9-10"), then you won't have that same problem UNLESS the tree is growing very slowly, but that is less likely due to its size (it's probably reached canopy status by then). This is why in some areas where small trees are tapped, the sap yield goes DOWN a LOT as time goes by. Eventually, your sap yield will be very low from these trees. Studies in Canada have pointed this out, and tapping guidelines were developed to prevent it. It has been recommended in Canada to not tap smaller trees, and suggested that it would be a good idea to cut back on tapping intensities (when you put in a second tap) to avoid widescale drops in sap yield. Politically not very acceptable at the moment though.

A lot of the equation though is driven by growth rates. If your trees are growing very fast (you've thinned the stand recently), they'll take more abuse (tapping when small). If not, due to climate (too cold up north), poor soils, or suppressed trees, then tapping these small trees or overtapping large trees isn't helping either the tree or the producer in the long-run. I hear quite frequently about people "thinning with a tapping bit." While this might be OK in theory, the better practice in a young stand is to first select what will be your eventual crop trees (leave spares), then thin the woods, tap the residual trees (even if small), but not your planned crop trees, and plan on thinning the residual trees you tap the next time you retube the woods. That way, your crop trees don't get the internal damage, but do get room to grow, while the trees you do plan to eventually thin (10-15 yrs later), can produce some sap for a while, but are then culled out to allow your crop trees to grow even more.

[adk1]

thanks for the information. So, on gravity tapping to a depth of 2" is the best bet for sap flow, but going down to only tapping to a depth of 1.5" will decrease sap flow slightly but will be better for the tree? (8-10" dia)

[DrTimPerkins]

Diameter isn't the biggest factor affecting internal damage (there is only 1/16" difference between 1/4" and 5/16" spouts)....taphole depth would be more important. If you do tap small trees, use shallower tapholes. Under good vacuum this won't impact yield too much. If you're using buckets, bags, or gravity tubing, it will definitely negatively impact your production.

Height, which is related to diameter (usually) is important to gravity flow....essentially, how long a "pipe" do you have from the taphole to the top of the tree for sap to run out of. For vacuum, height or diameter is somewhat important as well (up to about 12-15" in diameter), but is less so given that you can pull sap laterally and vertically, so that you're not just relying on sap coming from above the taphole.

[Goggleeye]

I've got fairly large quantities of sap from those 7-10 inch trees, 12-15 gallons and sometimes more, all on gravity. The trees down here in Missouri seem to grow very fast. Seems like a lot of the younger trees that are not under heavy competition that I've tapped still add about 1/2 inch to 1 inch in diameter of growth every year.

Dr Tim, I guess my question for you would be, in a rapidly growing tree with a long growing season and very good soil, how long will it be before the non-functional wood becomes functional (OK to tap) again. Can a person assume that if the tap wound is covered with healthy wood the first year, and the tree is averaging 3/8 inch per year new growth, that the tree will have 2 or more inches of functional wood over the old tap wound in 5-7 years?

Mark

[DrTimPerkins]

I've got fairly large quantities of sap from those 7-10 inch trees, 12-15 gallons and sometimes more, all on gravity. The trees down here in Missouri seem to grow very fast. Seems like a lot of the younger trees that are not under heavy competition that I've tapped still add about 1/2 inch to 1 inch in diameter of growth every year.

Dr Tim, I guess my question for you would be, in a rapidly growing tree with a long growing season and very good soil, how long will it be before the non-functional wood becomes functional (OK to tap) again. Can a person assume that if the tap wound is covered with healthy wood the first year, and the tree is averaging 3/8 inch per year new growth, that the tree will have 2 or more inches of functional wood over the old tap wound in 5-7 years?

Hi Mark,

First, non-functional wood will never become functional again. The taphole wound and stain must be covered by newly formed (functional) wood before that general area is useful again for producing sap.

Those growth rates are not normally seen here in the cold, dark north. Very different circumstances. However, once a tree grows enough wood to cover the taphole to a depth greater than the taphole depth used, it is fine to tap there again. Even better if you don't have to (meaning if you have plenty of other tree circumferance to tap). It becomes a matter of probabilities of whether or not you tap into stained wood. If you find you're doing that a fair amount when tapping, you should lighten up on your tapping regime to allow more wood to form.

[Amber Gold]

Good information from Dr. Perkins.

Goggleeye, once the wood is non-functional, it will always be non-functional. Am I correct, the wood is basically dead?

[DrTimPerkins]

Goggleeye, once the wood is non-functional, it will always be non-functional. Am I correct, the wood is basically dead?

In general that is correct....the majority of the tissues in wood itself are dead, but they are still functional for water/sap transport even when dead. It is only when the tree is wounded, and staining occurs (or heartwood forms), that the vessels are plugged up and that area is no longer functional in terms of sap/water transport. Even at that point, the stained wood is still functional from a structural perspective.

[Goggleeye]

Thanks for the response, Dr. Tim. I guess I may have been a bit unclear in part of my question. I understand once non-functional, always non-functional from a sap-flow transport perspective. I meant to imply when does the non-functional area become functional again because of new growth over the top of the wound, which you answered. By the way, which month does the sun finally appear in your southern sky in the cold, dark north?:)

[DrTimPerkins]

By the way, which month does the sun finally appear in your southern sky in the cold, dark north?:)

July I think. :D

[morningstarfarm]

ok..I have a small grove of red maples that are 4-6"..many of these are marked to be culled..have tapped those cull trees for 4 years now..trying to kill them..they heal every year to the point where i have a hard time finding any scars, and look just as healthy as the little ones next to them that i am planning to keep..would I put them on vacuum?..no..but on gravity I wouldnt hesitate to tap them if there is no other alternative.

[DrTimPerkins]

ok..I have a small grove of red maples that are 4-6"..many of these are marked to be culled..have tapped those cull trees for 4 years now..trying to kill them..they heal every year to the point where i have a hard time finding any scars, and look just as healthy as the little ones next to them that i am planning to keep..would I put them on vacuum?..no..but on gravity I wouldnt hesitate to tap them if there is no other alternative.

And you are completely within your rights to do that, and if the stand has been thinned so you have rapid growth, it might not be such a bad thing. However, somebody who isn't going to cull them or thin the woods might wonder 20 yrs later why they have very poor production....that is what I was trying to explain.

Oh....one more thing that sometimes people don't understand....vacuum doesn't cause any additional internal staining within trees compared to gravity. The two mechanisms (sapflow and staining) are different and not related.

[bowtie]

how long can a tree be tapped for? i 've heard people say they are tapping the same trees that their fathers or grandfathers had tapped. it seems you would eventually run out of"good" tapping area. i think that we should as "producers" of a natural product be thinking about the long term, maybe if you are tapping smaller trees you should be planting new ones. i've found a place that sells 3yr old 3-5 ft sugar maples for a couple bucks apiece. i plan on planting at least 50 a yr. i might not get to ever tap some of these trees but hopefully my children will. i believe in trying to put more back than i take out, i know it's not always possible but if we keep that in mind we will all be further ahead.
on a different note what is everyones take on soft maples, specifically silver maples, i have quite a few of these around and just came off the hill from marking my maples and i planned on tapping these. good idea or not?? would really appreiciate advice.

[DrTimPerkins]

how long can a tree be tapped for?

If conservative tapping guidelines are practiced (trees allowed to reach minimum size before tapping, no-overtapping), then sap collection can be done as long as the tree is alive and healthy.

[JoeJ]

I have 1/3 of my 978 taps (314 on this section, South aspect) on a piece of old farm land that is now forested with about 95% smaller size sugar maples. The trees this year average 10.5" in diameter ( I measured them). I tap trees once they are 8" DBH. I use vacuum that ran at 24" during 2008, 2009, 2010 and 26" in 2011. I measure the volume of the sap from these trees every day ( separate tank). The sap volume results were 22.5 gal per tap in 2008, 32.1 gal per tap in 2009, 31.2 gal per tap in 2010, and 28.3 gal per tap in 2011

The results from another separate section of 282 taps (East aspect) with a slightly larger average diameter were 23.2 gpt in 2008, 33.4 gpt in 2009, 29.2 gpt in 2010 and 29.1 gpt in 2011. From my experience, it is very possible to get good volumes of sap from 8" to 12" diameter trees and make a 1/2 of syrup per tap like I have for the past three years.

[Greenwich Maple Man]

What kind of vacuum pumps do you run? Must be a really tight system.

[DrTimPerkins]

....The trees this year average 10.5" in diameter ( I measured them). I tap trees once they are 8" DBH. I use vacuum that ran at 24" during 2008, 2009, 2010 and 26" in 2011. I measure the volume of the sap from these trees every day ( separate tank). The sap volume results were 22.5 gal per tap in 2008, 32.1 gal per tap in 2009, 31.2 gal per tap in 2010, and 28.3 gal per tap in 2011

Matches the results of one of our research areas with trees that size very closely. Good vacuum, good taphole sanitation practices = excellent results.

A tree that is 5" in diameter has a cross-sectional area of 19.6 in^2
A tree that is 8" in diameter has a cross-sectional area of 50.3 in^2, or more than double that 5" tree
A tree that is 10" in diameter has a cross-sectional area of 78.5 in^2, or four times that of a 5" tree

[danno]

Sap yield will depend upon several factors. If on gravity, a tree will produce far less sap than on vacuum, and more still on high vacuum, especially if good taphole/tubing sanitation practices are used. 15 gallons of sap from a 6-8" tree on vacuum is not unbelieveable....the better question.....should you be tapping 6-8" trees? Most tapping guidelines suggest first tapping at 9-10" minimum.

Dr. Tim - I believe one of your presentations in Verona was on "good taphole/tubing sanitation". I did not make that one, but I did attend your vacuum research presentation. Excellent as usual. I was surprised by your earlier findings that running mainline right to the taps was not increasing sap yield. Maybe once you're able to better find a way to discover vac leaks in 1/2" line you'll begin to see results.

Anyway, can you give us an abridged version on what you've discovered regarding taphole/tubing sanitation and best practices. I've got lats/drops ranging from 1-5 years old, new CV's.

[JoeJ]

I purchased a Sihi 2 stage oil cooled vacuum pump for the 2011 season. Besides a good vacuum pump, I have lots of main line, short lateral Lapierre semi-rigid lines, no more than three taps per lateral, check valve spouts ( as of 2010 season) and no red squirrels. (They all died of lead poisoning)

[spud]

JoeJ,

That is outstanding production. I bought a new Kinney 2 stage oil cooled pump that is 10hp. I have on average 4 taps per lateral. I would love to get 32 gallons of sap per tap. I think the high vac with the check valves are the key to your operation. Although your short laterals and many mainlines with few leaks are a big factor. I am in Essex often and would love to see your set-up some time.

Spud

[DrTimPerkins]

...can you give us an abridged version on what you've discovered regarding taphole/tubing sanitation and best practices. I've got lats/drops ranging from 1-5 years old, new CV's.

Don't want to hijack this thread.....that conversation is going on at http://mapletrader.com/community/showthread.php?14682-Leader-Check-Valve-Spout-Adapter&p=170927#post170927

[rookie]

thank you dr. perkins for your vast knowledge, i feel like iam educating my self just reading you posts