When to tap

[spud]

I was reading a few of PMRC studies this morning. The one study was on vacuum. A test was done using tree's that averaged 7.5 inch. In that test these trees were producing 22+GPT on high vacuum (25 inch). My question is would these trees continue to put out these kinds of numbers year after year? Some people are saying no but others are saying yes they will. Has research been done on this.

I also read that the difference between using a 5/16 spout and a 7/16 inch spout is almost twice the size of the wound. Although the amount of stain from a 5/16 spout is about 80% of what a 7/16 spout makes. With that said how much harm would really be done to a tree that is 6 inches or bigger? I know every tap hole causes dead wood in a tree so the smaller the tree the more dead wood verse good wood there would be. If I was to tap a six inch tree every year would I eventually run out of good wood to tap? Would the tree grow quick enough to keep up with my tapping?

The study on (when to tap) suggest that if a person was to tap their woods in early January they would stand to make more GPT. The study was done in 2006 and then again in 2007. Both years produced 6.5-6.8 GPT more sap then people waiting until February to tap. It also showed that the early tapped trees did slow down later in the spring (but not much ). All in all I see no reason to wait until February to tap ( If )I stand to possibly make 6.8 more gallons per tap. That would be 44,000 more gallons of sap per year in my woods alone. I am seeing the pro's to tapping early but what are the con's?

I am wondering if PMRC has continued to tap early since 2007 and do they have sap amounts charted?

Spud

[ericjeeper]

I personally would never tap a six inch tree.

[spencer11]

My absolute minimum is 8" and I only have a couple of those

[DrTimPerkins]

First off.....it is CRITICALLY important to keep in mind that we are not encouraging people to tap such small trees. We do this on occasion for a couple of reasons....the primary one being that we CUT these trees down at some point to measure the internal staining. Since we don't want to cut down all our large trees, and because they are a lot easier to deal with, we will sometimes use small trees. . It also sometimes happens when we need a sizeable number of trees within a fairly tight diameter range. Since most of our trees > 10-12" dbh are already tapped, we sometimes need to go a bit lower for these studies. This is not an endorsement of the practice of tapping small trees

Secondly, while it is sometimes possible to get high yields with such small trees, it occurs partially due to the fact that they are growing well (not suppressed....many of the trees in that study were open-grown), and partly because we are using very high vacuum in some cases.

In our production/demonstration sugaring operation, we tap dominant or co-dominant trees that are 10" and above. This is a recent change. Before last year we only tapped trees 12" and above, and only 1 tap per tree regardless of size. We now put 2 taps in trees 18" and above if they are in good health.

To the question of whether they would continue to put out that kind of yield for a long time period.....it depends. The major factor is growth rate, but it also varies depending upon dropline length, tapping depth, etc. It all comes down to how much non-functional wood you produce in a tree by tapping (and the creation of the internal wound...the stain....the zone in which sap does not move through). If you build up too much staining, you reduce the ability of the tree (and the maple producer) to move sap through the stem. In essence, a large part of the stem becomes compartmentalized. When this happens, production drops.

We (mostly Dr. Abby van den Berg) are actually working on a model to allow these types of calculations to be made, and will be presenting this work at the upcoming maple meetings starting in January. After that, and based upon the feedback we receive, we will likely put some version of this tool online so that producers can use it to determine the tapping sustainability on their own.

As far as tapping early....we have shifted our own tapping (on vacuum) somewhat earlier, but this is primarily a response to changing climatic conditions. One other factor is that it takes us a bit longer than typical to tap, since we are also setting up our experiments at the same time.

Finally, no....that particular study ended in 2007. While I agree that to continue it might have been interesting, there are too many things to do just because they are interesting. Because of limited resources (mainly funding and personnel), we can only do a certain amount of work each year. In many cases, the work we do is dependent upon the funding we receive.

[Benson]

Hi everyone i just found this site yesterday. I have been around sugaring my entire life and love it. I just moved to southern NH and is looking for some one that is in need of a young hard working guy to help them do every thing there is to do with sugaring. Please write me.

[Sunday Rock Maple]

We used to have a 4 week window with buckets and metal spouts before the majority of them were drying up. What do you folks with experience think that is with high vacuum and CV's --- 8 weeks?

In regard to tree diameter, I will tap a soft maple that is 2" less in diameter than a hard maple (all other things being equal) because of the faster growth rate of the soft.

[steam maker]

jees benson i wish u lived in my town!!!!! but im sure someone within a stones throw will scoop u up!!!!!!!!!

[spud]

Thank you Dr. Tim for your response. You mentioned that a smaller tree could produce a good amount of sap if the growth rate of the tree was good. What would be considered a good growth rate for a maple that is now 6 inch's? I thought someone at one time said 1/4 inch per year is normal.

You also mentioned two other factors and one being drop line length. The other being tapping depth. I don't understand how drop line length could be a factor (could you please explain?). How deep of a tap hole should a person go if they were to tap a 6-8 inch tree?

You also said that you shifted your tapping to a somewhat earlier time due in part to climatic conditions. So when do you tap your trees at PMRC?

Spud

[DrTimPerkins]

You also mentioned two other factors and one being drop line length. The other being tapping depth. I don't understand how drop line length could be a factor (could you please explain?). How deep of a tap hole should a person go if they were to tap a 6-8 inch tree?

You also said that you shifted your tapping to a somewhat earlier time due in part to climatic conditions. So when do you tap your trees at PMRC?

Minimum growth rates would be 1/4" diameter each year and decent crown exposure. I've said this before, but if you have a lot of small, slow-growing trees, you're better off thinning to release some of the small trees than to tap them.

Drop length, taphole size, taphole depth, and other factors affect how much of the tapping band is wounded (internally) by tapping, and thus how much wood in a certain area is made non-functional (not able to transport water or sap). Too much compartmentalization in one area will reduce the ability of the tree to move water, which is necessary for photosynthesis and thus carbon acquisition. This is all part of the presentations we'll be doing this winter and will be the focus of a publication within the next 6 months.

IF you do tap smaller trees (not recommended), then you should use a very shallow taphole if possible. 1-1.5" maximum depth.

We now tap around mid-February, but this varies somewhat based upon what experiments we are doing and the weather. Again, takes us longer than usual to tap because we are both setting up research and tapping at the same time. We have about 3,000 taps in our production/demonstration operation, plus a few hundred others on more intensive research projects that are typically tapped on a different schedule.

[adk1]

Last year I was tapped on valentines Day because of the weather. All the other locals around me were as well. being my first year I was going off what they do. I wont do that again. When they were tapping their trees were running. When I tapped my trees were still frozen solid. My estimate is that my bush started running a week later than everyone elses around me. Having said that, I should be good on typical years to be tapped on the 1st of march. I will tap a few trees on sacks around the house to keep tabs on runs.

[sapman]

[QUOTE=DrTimPerkins;196839] We now put 2 taps in trees 18" and above if they are in good health.

Tapping this way, are you finding the second tap gives more than only a 50% increase, which was evidenced by prior research? I know the recommendation was only 1 no matter what size a few years ago. Just wondering if you're now finding the second tap more worthwhile than thought.

Thanks