.250"dia. Taps on Gravity

[English River Maple]

Hello, we are currently in process of installing approximately 500 drop lines on gravity pipeline. I am curious if anyone has had the experience of using .250"dia. taps on a gravity pipline system? Will we see much at all in decreased sap volume overall? We intend to have this in place for the 2012 maple season. We have between 10 and 20 taps per lateral line with good down-ward grade. Vacuum is in the plans for 2013 (depending on profits of 2012).

Thanks for any info you can share.

[DrTimPerkins]

Hello, we are currently in process of installing approximately 500 drop lines on gravity pipeline. I am curious if anyone has had the experience of using .250"dia. taps on a gravity pipline system? Will we see much at all in decreased sap volume overall? We intend to have this in place for the 2012 maple season.

There has been almost no research on 1/4" spouts. They were put on the market several years ago (when syrup supplies were very low) with the intent of allowing people to tap in the fall, and then ream out the holes to 5/16" and put in a new spout in the spring. This didn't prove to be an effective strategy (based upon research and user experience).

Small spouts (5/16" or 19/64") on gravity will generally produce near what a 7/16" spout will, somewhat less in some years. Going down another 1/16" in diameter probably continues this trend. There is less of an effect on yield loss under vacuum.

The real question is....why bother with the 1/4"....especially on gravity?

[red maples]

I don't know that much about the 1/4" spouts but I remember reading there is a decrease in sap from them especially for gravity. I would say if you plan on vaccuum for the 2013 season make sure that you set up your lateral line system for vacuum you might get a little less sap as you wanna try to have a max number of tap set at 5 per lateral. There are less taps per lateral but it will save you many hours of labor and money re-running laterals(I made that mistake) and I would go right in with leader stubbies and seasonal straight adapter for gravity you can go CV's if you like but with vacuum many will say go with CV's in 2013 then that will save from having to redo all your drops for the 2013 season as well.

You can do what you like but I cursed at my self a few times for not doing it right the first time!!!

What ever you decide to do I would go with a seasonal spout you will spend a little more for the spout but it will pay for itself a few times over in the long run.

[English River Maple]

Thanks for the advice. Basically, we did one small bush of 300taps with 5-10 (plans for vacuum in this bush as soon as funds permit) taps per lateral. We intend to make adjustments to the laterals during the installation of the vacuum system to have no more than 5taps per lateral line. We will, once again, be covering ground we already covered, but we'll have to take the pain and just do it. We just installed another 140 in another small bush with 15-20 per lateral. This is 2nd in priority for a vacuum system...and yes, once again, when we convert to vac, we will have to take the pain of reducing taps and running more line. It's not 5,000 taps, so shouldn't be too bad.

One last question of advice; Is it a wise decision to never use a tap smaller than 5/16"dia to reduce damage to the tree? There is only 1/16" difference obviously with 1/4", I can't imagine that 5/16" is "hurting" the tree much more.

Thanks

[DrTimPerkins]

One last question of advice; Is it a wise decision to never use a tap smaller than 5/16"dia to reduce damage to the tree? There is only 1/16" difference obviously with 1/4", I can't imagine that 5/16" is "hurting" the tree much more.

There is a trade-off between taphole size and wounding. In brief, under vacuum and under gravity, as you increase tap size, the wound increases in size and the yield increases. However with vacuum, yield levels off at about 5/16". Above that, you don't see any increase in sap yield. Below that, there is a gradual drop off in yield. With gravity, yield will increase "slightly" above 5/16", but generally by a fairly negligible amount in most seasons. The reason there is a difference between gravity and vacuum response is the difference in the "flow regime."

Microspouts (~3/16") are only for vacuum use and produce considerably less sap than a 5/16" spout (50-60%), although they do produce a very small wound as well.

There is very little difference in wounding between a 1/4" (4/16") and a 5/16" spout.

Since you're on gravity now, I wouldn't use 1/4" spouts. On vacuum, the yield loss is probably less than it would be on gravity. Personally, I've not heard a "good" argument for using 1/4" spouts. As I said, they were designed for a certain purpose (to allow fall tapping with spring reaming of the same hole to a slightly larger diameter). This just didn't pan out based upon research evidence and operational experience. I wonder why they even bother selling them -- except they've paid for the injection mold to be made and want to recoup their investment.

[English River Maple]

Dr. Perkins, thanks again for sharing your opinions and experience. Great information and advice.

We will be installing 200 buckets in 2012 in addition to our 500 gravity taps. For the gravity taps, I think our direction in tap size is now more clear. As for our bucket spouts for 2012, 100 taps are 5/16, the other 100+ are the old heavy 7/16" (boat anchors) leader spouts with the casted hook attached. I am excited to see the difference in production (if any) between these 2 different style spouts. Fun activities.

Jon