Harvesting Chestnuts, Appropriate Technology

Hi Grant, our chestnuts are getting ready to pop off and I am thinking there has to be a better way to get to the nut than what we've been doing. Are there any affordable commercial chestnut harvesting solutions available in the US or have you come up with any appropriate technology applications to harvesting chestnuts? We only have five mature trees, currently, but have high hopes for a thousand feet of alley plantings.
Additionally, any suggestions on weevil prevention?
I would love to come out to the workshop and I hope I am in the running for a ticket!
Thanks,
Daniel in WNC

Daniel Bowman wrote:Hi Grant, our chestnuts are getting ready to pop off and I am thinking there has to be a better way to get to the nut than what we've been doing. Are there any affordable commercial chestnut harvesting solutions available in the US or have you come up with any appropriate technology applications to harvesting chestnuts? We only have five mature trees, currently, but have high hopes for a thousand feet of alley plantings.
Additionally, any suggestions on weevil prevention?

This is a super important question - and not one most people think of!

There is a very specific function of cost of labor vs harvesting technology. Most chestnut growers in the US - even the ones you assume are super mechanized - end up using $50 nut wizards (hand held golf ball picker-upper tools) for their harvesting with low-cost (sub-$10/hr), child, or volunteer labor. The University of Missouri went as far as doing a time-in-motion study for the different harvesting methodologies, and found that the handheld harvesters did indeed win as long as labor was cheap and available.



There are various mechanical sweepers that have been developed (mostly for golf balls) with varied levels of success.



The newest, coolest, likely best technology for nut harvesting that works is vacuum harvesters. Most of these come from Italy, FACMA being one manufacturer.

The University of Missouri just bought a modest-sized FACMA C300T vacuum harvester, which is detailed here: http://www.centerforagroforestry.org/pubs/action/1312action.pdf





As for weevils, I think diversity and orchard maintenance are preventative factors. Livestock in the understory will help to eliminate the pest cycle (eating larvae). PIGS ARE YOUR YEAR-ROUND FRIENDS!

Chestnut weevils may also be more of a bioregional problem like Japanese beetles. In Iowa, we have essentially no chestnut weevil pressure, out East I hear it is becoming a management consideration.

Woah. I had no idea the "nut wizard" was anything more than a backyard gimmick! I am amazed. I assume, then, that the "cheap labor" approach to removing the husks is thick gloves? Pliers? Roll it off with your boot? Any thoughts on a quicker method that doesn't come in a shipping crate from Italy? Actually, that vacuum one looks pretty great, but does the vacuum hose come out so you can get between trees without having to drive the tractor over the whole harvest area? That would be important for our interplanted alley setup.

Regarding pigs, can they get at a chestnut in the husk? We haven't put ours on pasture, since we are maxed out on sheep and cow grazing space. Instead, we keep our little group of feeder pigs in a forest edge hillside area, predominated by various saplings, blackberries, multiflora rose, vines, poison ivy. They are doing a good job rooting it out and terracing. At some point, we might try to let them graze with the other livestock, but I am hesitant. In the summer they have a strong desire to wallow and will overturn, splash, roll onto their water trough and root up a puddle into a mudpit. We attempted to use an expensive pig waterer but they would just repeatedly splash out that little cup and wallow under it, too. We went back to a 20gal tub with a very heavy flat stone in it, which they can't overturn but when it runs dry they will try and push it all around. Needless to say, we try and move them to a fresh spot every 2-4 weeks. I hate hauling that stone around and might invest in a few 25lb dumbbell weights. After moving them, the old spot gets seeded and mulched and gradually converted to pasture or prepped for terraced berry planting. Next year, for the first time, the folks we get our feeder pigs from will be farrowing out on pasture, so maybe the piglets will learn some better grazing instincts.

Daniel Bowman wrote:WI assume, then, that the "cheap labor" approach to removing the husks is thick gloves? Pliers? Roll it off with your boot? Any thoughts on a quicker method that doesn't come in a shipping crate from Italy? Actually, that vacuum one looks pretty great, but does the vacuum hose come out so you can get between trees without having to drive the tractor over the whole harvest area? That would be important for our interplanted alley setup.

Most properly-filled chestnuts will drop free of the burr, and a little disruption will knock the rest of any grounded and worthy ones free of it. Prying open burrs is usually a time-burglar yielding unfilled nuts.

The vacuum has a "beater bar" rake ahead of it that windrows ahead of the vacuum. Not sure on detachable suction hose, I know some models have it but I don't think its common.

Mizzou found the advantage of the nut wizard is that the operator can visually discern nuts from burrs and the savings in cleaning time is had on the frontside. A vacuum with a 4-8" opening wants to suck up the lighter burrs before it ever gets to the nuts.

"Vacuums suck!" <----I slay myself!

I can vouch for the weevil problems in the East. It makes our nuts very difficult to market. The customer does not want to see one single live squiggling maggot-looking weevil larva.

Harvest has to be a diligent process or the squirrels get the upper hand. We use gloves. I like the look of that nut wizard.

Hmm.. I wonder what the ratio of properly filled to small size nuts usually is. I would say our Chinese chestnuts (50+ y.o. trees) produce heavily but not so many are properly filled. Maybe that is half my problem? Hopefully the next generation of trees will be easier to harvest.

Incidentally, I was just turned on to the pastured pig waterer on farm hack and it looks like just the ticket. Gonna try and make one this weekend!

There are a couple of sources for the rubber finger type harvesters:
https://baganut.com/collections/pick-up-chestnuts
(in Florida)
and
http://www.nutpickerupper.com/
(in California)
The products appear identical, so pick the closer for lower shipping costs.

Freezing the chestnuts immediately after harvest is supposed to reduce weevil problems.