changing drops

[Howard]

I have 15000 drops that need to be changed, Instead of putting in a lot of man hours. how about just putting on a leader check valve?

[Ultimatetreehugger]

If your drops are long enough to provide an adequate tapping range than have at. I think you will be surprised by the yield increase.

[maple flats]

How old are the existing drops? While CV taps will help quite a bit, the drops should still be changed every 3-4 years and the first season on new drops you can use a seasonal tap, switch to CV in years 2,3 and 4 if you go that long.
Personally I change after 3 years.

[jrgagne99]

I think there is a recent study from UVM indicating that Check Valves are very effective when used on old drop lines. Not quite as good as a brand new drop, but pretty close. For me, the article cast some doubt on the wisdom of replacing drops every 3-5 years, since permanent stubbies and seasonal CV-adapters can get you within 90-95% yield vs. brand new drops. Perhaps Dr. Tim will chime in here.

[Howard]

The drops are 6 years old. Instead of replacing drop I was going to put check vale on at tapping time.

[tcross]

while i only have 350 taps, i do what you are suggesting. i only replace drops that look like hell, or get too short. with the idea of the cv not letting any back flow through the check valve it seems logical! i know my yields have been pretty darn consistent using this method. Some of my drops are 6-7 years old and are still flowing quite well after my sap turns on me and i call it a year!

[DrTimPerkins]

I have 15000 drops that need to be changed, Instead of putting in a lot of man hours. how about just putting on a leader check valve?

This is normally what we do. Too busy right now for long explanation. Will come back to this tomorrow.

[DrTimPerkins]

There has been a great deal of research done and written on this subject. You can find a lot of it by going to https://mapleresearch.org/ and searching for "sanitation" or check valves" or "Perkins". That'll get you a lot of info.

There is also a video of spout/tubing sanitation at https://www.youtube.com/watch?v=z35z6oZDz4A&list=PLZP4fDl-nB9-4aZkQyDR070QpxcAr02q5&index=5&t=12s in the "Keys to High Sap Yield" Playlist https://www.youtube.com/playlist?list=PLZP4fDl-nB9-4aZkQyDR070QpxcAr02q5

Note that all this applies to 5/16" tubing. 3/16" tubing responds a bit differently.

In short, as others have mentioned, CV spouts or adapters will not produce quite as much sap as replacing drops and spouts, but the cost and labor involved in using CVs is so much less that the net profit tends to be higher. Replacing spouts only, without replacing drops periodically (every 3 yrs is the recommended interval if NOT using CVs), will not produce decent sap yields, and even though the cost is lower, will not produce among the highest net profits.

Use of chlorine-based sanitizers will produce similar, if done correctly (proper concentration, long-contact time, with rinsing), can produce slightly higher net profits, but also risks the problem of attracting squirrels and other animals to attack the tubing system, reducing profits.

As I stated, we use CVs for most of our production bush at UVM PMRC unless there is a specific study using other types of spouts where we need to reset the system to get a common level of sanitation and we're not able to use CVs across all treatments. In some sections of the woods we haven't replaced drops for a long time. In this case we replace drops only when the lateral line or fittings start to fail.

[fred]

i think the original question needs to be addressed. howard said they need to be changed. tell me more about that ,not about a CV spout making it last longer. whats going on that "they need to be changed"

[Howard]

Fred, Im at the 5th year of using drop. I change out spouts yearly. Im trying to increase my yield, and trying to limit labor.

[tcross]

i believe what he was saying is, he's at his normal time period with his drops where he normally replaces them and he's asking if he uses the cv spouts, will he be able to avoid replacing them and not loose production.

[jrgagne99]

he's asking if he uses the cv spouts, will he be able to avoid replacing [the drops] and not loose production.

The answer is a qualified "yes".

UVM's research suggests that CV's can be used instead of replacing drops and have pretty close to the same effect. One exception is if the drops are deteriorating to the point of failure (i.e. tees are breaking and/or really nasty stuff has formed in the "U" of the drop).

[fred]

if you look at the results from cornell and steve childs work over the past 10 years on this specifically. even with CV after so much time he had issues with production. it absoutely pays to replace at the point your at. first year could be any spout after that CV have more value.

[DrTimPerkins]

On the contrary, Steve Childs typically showed better results for the CV than UVM studies. Our work usually brought the average of studies on CVs lower, Cornell’s pushed it up. That is likely because he frequently used older tubing material than we do. Older/dirtier tubing provides more room for improvement.

[fred]

i dont have the chart. while that is true tim, at 5 years it pays to replace the drop.