Getting Started with a Growth Chamber

We’ve received a number of inquiries about building germination chambers so we have decided to provide some consolidated resources and guidance.

An important first step is to consider what the purpose of the chamber actually is.  There are a number of horticultural practices that benefit from dedicated, environmentally controlled spaces. These include germination, starting, propagation/transplanting, sprouting of tubers and rhizomes, and grafting. These all fall under the category of “growth chambers.”

Continue reading Getting Started with a Growth Chamber

Launching of The Ag Engineering Podcast?!

Hello friends and farmers!

I am excited to share a new idea and am looking for your feedback and support! Today, I am releasing Episode 0 of the UVM Extension Ag Engineering Podcast! This is a short form audio segment on tools, tips, and techniques to improve the sustainability of your farm.

This is a trial episode to introduce the idea, and give you a feel for what to expect. It is 5 minutes in duration, but I expect future episodes will be 10-20 minute interviews with farmers talking about a specific piece of equipment or farming practice that has changed their farm for the better.

Have a listen, and let me know what you think! If you want to hear more or have a topic idea I’d love to hear it. You can either e-mail me at andrew.chamberlin@uvm.edu or enter your comments in this survey.

Thanks!
-Andy

Expanding Your Tunnel Vision, Manchester NH

Andy ventured down to the high tunnel conference hosted in Manchester, NH on December 4th to expand his knowledge on protected culture. This program was co-sponsored by the Universities of Maine, New Hampshire and Vermont and the Maine Organic Farmers’ and Gardeners’ Association, and was supported by Northeast SARE project LNE 15-343. His notes follow.

I wasn’t able to attend day one which was mostly pest and diseases. I did attend the second day which included more practice-specific information. The conference was filled with farmers and detailed information about growing under high tunnels. It was great to see many familiar faces, mostly cheery now that things have mostly slowed down and seed catalogs are arriving in the mail full of hopes and dreams.

The day started off with Vern Grubinger (UVM Extension and VVBGA) talking about the history of high tunnels, followed by every single different type or construction practice he’s seen. The list is long, and it covers everything as simple as a DIY caterpillar tunnel to a fully automated and digitally monitored greenhouse system. It was pretty nice to see many different features and options collated and presented together.

If you’d like to take a peek at the presentations they are posted here: https://extension.unh.edu/blog/2018-high-tunnel-conference-presentations-available

There were quick lightning rounds with short presentations sharing new research projects like saffron, scouting, and soil moisture. A couple takeaways:

  • Using shade cloth in the doorway is a useful curtain to keep birds out
  • Potted plants actually need less water than they probably are provided
  • Wrapping baseboard rigid insulation in roofing flashing makes it durable for rodent pressure or weedwhackers!
  • A presentation on water usage shared that many farms have no idea how much water they use and “pulse irrigation” (shorter more frequent watering) may be better for the plants, the soil, and the systems. This is a take away that I will put into practice, especially having a well with low flow it would be better to water smaller amounts more frequently than flooding hundreds of gallons in the evening that can wash away nutrients and promote diseases while the soil and plants sit saturated overnight.

The afternoon included a grower panel which is always fun. The panel discussed topics like mulch practices and most profitable crops. The top crops were noted as #1 Tomatoes and #2 Winter Greens! If you keep good records of the time you put into the crops, the prices you ask for them, and the number of successions planted you can analyze the highest value crops for your farm.

It’s rare that I go someplace without a camera, so here are a few shots I shot at the conference.

-Andy Continue reading Expanding Your Tunnel Vision, Manchester NH

Upcoming Produce Safety Training (November 6-7, 2017)

The Vermont Agency of Agriculture and UVM Extension are co-sponsoring a VT-Style Produce Safety Alliance (PSA) Grower Training on Tue-Wed, November 7 & 8, 2017 (8:30am – 5:00pm) at the VYCC Monitor Barn in Richmond, VT. This is the official required training for FSMA covered farms (Click here to determine whether your farm may be covered or exempt).


The $30 heavily subsidized training fee includes the massive training manual, multiple meals, ample coffee, and the Association of Food and Drug Official (AFDO) certificate (a $130 value—not including space rental or instructor fees!). The AFDO training certificate satisfies FSMA Produce Safety Rule training requirement.

EVERYONE is invited: Regardless of scale, annual sales, or market outlets, all produce growers can benefit from learning about integrating practical produce safety practices on a working produce operation. Technical assistance providers, educators, and regulators are also invited and will benefit from this training. Whether you are a covered farm fully subject to Produce Safety Rule (PSR) regulations, or an exempt farm required to keep certain records related to your exemption, all aspects rule compliance will also be covered during this training.

The Training Schedule at a glance:
Day One (November 7, 8:30am–5:00pm) will provide an introduction to the FSMA Produce Safety Rule, employee health, hygiene and training requirements, and information about management of soil amendments as well as domesticated animals and wildlife. Includes on-farm exploration to apply concepts in the field.
Day Two (November 8, 8:30am–5:00pm) will cover agricultural water, postharvest handling and sanitation, and writing produce safety plans. Includes on-farm exploration to apply post-harvest concepts.

View more details and registration visit:  PSA Training Registration via Regonline

Building a Hoop House in One Day!

A fun day of learning during a hoop house install during one single day by Nifty Hoops at Bread & Butter Farm in Shelburne VT.

See photos from the day on our flickr page here: https://flic.kr/s/aHsm4yUQUL

IMG_7404

Like Nifty Hoops on facebook! https://www.facebook.com/NiftyHoops/

Visit Nifty Hoops website: http://niftyhoops.com/

Nifty Hoops has their own YouTube Channel! https://www.youtube.com/channel/UCj0g…

Check Out Bread & Butter Farm! https://www.facebook.com/breadandbutt… http://www.breadandbutterfarm.com/

 

 

Improved Ventilation for High Tunnels

I have received many inquiries about how to improve ventilation of high tunnels from growers with tunnels that have only roll-up sides. The issues they are facing tend to be either high temp, high humidity or both, leading to plant stress or disease. These situations tend to be in less than ideal sites for ventilation and/or temperature control. For example, crowded lots with trees or other significant wind breaks close to the tunnel, high southern exposure (which can be good of course), and/or simply calm sites that provide little ventilation.

Keenan Meier Shutters with flanged seal highlighted.

Roll-up sides alone tend to work for tunnels on sites with generally good air flow. Diffusion between inside and outside does happen, of course, but is slow and unlikely to achieve good ventilation along the center of the tunnel, especially with dense vegetation later in plant maturity. But, I think of a tunnel in this instance a bit like a wood stove. Without a chimney-effect natural draft, you’re really only getting ventilation from the sides and only then if there is a decent breeze. Warmer air and, therefore, humidity will tend to collect in the canopy and peak.

Passive wax cylinder louver actuator. [Photo Credit: http://www.littlegreenhouse.com/accessory/vent2.shtml]
This probably is OK in many sites for most crops. But not always. In many cases gable vents will improve ventilation by acting as outlets for warm humid air in warmer seasons and by allowing for low volume ventilation in colder weather. I recommend a simple 24″x24″ gable vent (for a 30’x96′ tunnel) on each end wall, with a thermostatic wax cylinder actuator like the ones made by J. Orbesen Teknik APS available from LittleGreenhouse.com., FarmTek, and Agricultural Solutions among others  The actuators require no electricity, are relatively inexpensive and are passively controlled by the wax cylinder based on temperature.

At the very least, when building end-walls consider framing in a rough opening to accept a 24″x24″ in the end wall so that a future install is easier. If you want to skip the expense of a louvered, wax cylinder system, you can use a manually-controlled sheet of plywood to open and close the vent. If you go with a louvered vent, seek one that has a flanged seal it closes against. Keenan Meier, and Munters-Euroemme has such flanged, louvered dampers.

Munters Euroemme fan with flanged seal being pointed out.

These have zero daylight when closed which results in a solid seal. Most others on the market that I have seen have no such closure seal.

Fans

Fans in greenhouses and high tunnels generally perform two tasks: (1) circulation / mixing / stirring and (2) ventilation.

  1. Circulation / Mixing / Stirring – Sometimes referred to as horizontal air flow or “HAF” fans, these fans are generally hung from the inside horizontal structural tubing.  They only mix the air.  The benefit of this is consistent, well distributed growing conditions.  It also ensures that your control sensors are seeing the “average” conditions of the space. Remember that HAF fans work to mix the space (circulate the air) but don’t significantly improve ventilation. HAF combined with roll up sides can do the trick, but the site is the key. There needs to be a steady cross breeze for any significant air exchange to occur.
  2. Ventilation – Ventilation, or “exhaust” fans provide air exchange between the inside and outside. This is really important in controlling temperature (cooling) or humidity (drying).  The only way to remove heat or humidity from a standard high tunnel or greenhouse is by actively removing air from the space and bringing in outside air.  Ventilation (cooling) systems are covered very well by Bartok and Aldrich (p. 70).  Basic rules of thumb for ventilation are 8 CFM/ft2 (of growing space) for summer cooling and 2 CFM/ft2 for cooler months.

References:

Bartok, J., & Aldrich, R. (1994). Greenhouse Engineering, NRAES – 33. Natural Resource, Agriculture and Engineering Service (NRAES). Retrieved from http://host31.spidergraphics.com/nra/doc/Fair%20Use%20Web%20PDFs/NRAES-33_Web.pdf

Rats (and other rodents)

Download the PDF version of this page here!

When considering storage rooms, wash and pack sheds with growers there is one topic that is sure to strike a nerve: RODENTS.

This document is intended to provide summary information about measures you can take to reduce crop losses from these pests.  It is the result of a review of current literature on the topic and feedback from the Listserv of the Vermont Vegetable and Berry Grower’s Association (VVBGA). This document includes both active measures (traps, rodenticides, FSMA compliant cats and ball pythons, etc.) and passive measures (sealing, doors, packing, hardware cloth, novel construction, accepting the loss, selling everything early). But why are these creatures so challenging?  Here’s some background1:

House Mice Can

  • Enter openings larger than 1/4 inch
  • Jump as high as 18 inches
  • Travel considerable distances crawling upside-down along wire
  • Survive and reproduce at a temperature of 24°F if adequate food and nesting material are available.

Rats Can

  • Crawl through or under any opening higher or wider than 1/2 inch
  • Climb the outside or inside of vertical pipes and conduits up to 3 inches in diameter
  • Jump from a flat surface up to 36 inches vertically and as far as 48 inches horizontally
  • Drop 50 feet without being seriously injured
  • Burrow straight down into the ground for at least 36”
  • Swim as far as 1/2mi in open water, dive through water traps in plumbing, and travel in sewer lines against a substantial water current.

As one grower put it, “To deal with rats, you’ve got to think link a rat!”

Bottom Line

Cleanliness and Sanitation – Keep food sources well contained and sealed up, reduce “harborage” (places they can hide and live including weeds around the edge of a building), minimize available standing water. In short, make it unappealing and uncomfortable for them.

Rodent Deterrent Construction – Keep them out of the building. [References 1-3 provide very detailed guidance and novel, passive and relatively inexpensive construction ideas] Some examples from the references include keeping all wood products like cardboard, roots, or lumber off the ground and away from the building. Installing proper drainage with sand, stone and proper slope away from your building helps reduce moisture which can carry other pests like beetles and termites. Think about your exterior landscaping and its ability to trap moisture against the building. Keeping grass and weeds trimmed won’t leave a place for rodents to hide and travel. Think about all possible points of entry, sills, doors, windows, roofs. Mice can sneak into small holes and cracks so do your best to seal up all possible points of entry.

Population Reduction — Bait, trap, kill.

Using snap traps, sticky pads, poisonous bait are all the most effective ways of dealing with a rodent problem [References 5-7].

Responses from the VVBGA LISTSERV 

The following are responses from Vermont growers. These are some of their challenges and solutions related to rodents on their farms.

  • I have had over 20% of my sweet potatoes damage by voles.  Usually the largest sweet potatoes are the ones half eaten.  The next year I put five “yard windmills” in the sweet potato bed, 100 ft. long, along with a half stick of gum under the black plastic by each plant – cheap gum from the discount food store.  Both were done after I removed the row covers and before the vines spread. That reduced the damage to less than 5%. Very anecdotal and empirical data but worth exploring.  Supposedly the voles do not like vibration of the windmill and eating the gum gives them a bellyache, if fatal I do not know.  Bigger windmills, four inches in diameter and larger, with metal post seem to work better.  How much gum is actually needed I do not know. A SARE  grant in your future.
  • Not the cheapest retrofit, but have had the best luck with making all walls tin or concrete, and having rat traps permanently set at every overhead door jamb, since the seal is not 100%.  Ventilate with in-wall intake and exhaust fans instead of opening doors.
  • I recently tried the tin cats and was happy. Baited them by putting small amount of oats in the trap and tilting it so the grain slid to the end where the screen was. After the mice got a few seed through the screen, they were drawn into the trap to get the remainder. Two mice in the same trap on the first night. The downside is that you have to clean out all the grain each time so it doesn’t hamper the trap mechanism. Have used Contract waxy block in bait stations for at least 4 years. Switching to a different bait because I think they are starting to get a resistance.
  • I’ve been using that old root cellar all winter for 3 years now without any rodent problems. The process of having someone cement hardware cloth over every crack and crevice was time-consuming but really seems to have worked. I think I finally got rid of the rats in my toolshed through a combination of trapping and disturbing their nesting spots. I’m curious about rodent solutions that apply to the field and high tunnel. I’ve tried to keep cats but the fishers get them.
  • I have not had a single animal in the new barn that I built with the 12” concrete knee wall. I partly contribute the success to the fact that I do not set the bins on the ground. They are filled on the trailer and go directly from the trailer to the barn. This reduces the chance that a hitchhiker will take a ride into the barn.

  • We are a very small pumpkin farm and don’t have the storage needs for food, but I use lots of snap traps and dump those little, dead vermin bodies while wearing a happy smile!
  • We have only killed rats by accidentally moving a pallet onto one. Can’t bait them. They are very intelligent.
  • “We have a great barn cat and a Jack Russell terrier for our farm.”
  • Mice – kernel of corn wedged into mousetrap trigger covered in peanut butter. Rats – same as above but do not the set the trap for several nights and remove all other food sources (in chicken hutch empty all food containers) then set the trap.  Putting a milk crate over the trap prevents chickens, cats, dogs from getting caught.  Also works with chipmunks, and occasionally with red squirrels. Voles – hard to trap, run them down and stomp.

REFERENCES

  1. Baker R., Bodman G. and Timm, R. 1994. Rodent-Proof Construction and Exclusion Methods. The Handbook: Prevention and Control of Wildlife Damage. Paper 27.  http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1025&context=icwdmhandbook
  2. Hoddenbach, G., Johnson, J., Disalvo, C. 1997. Rodent Exclusion Techniques. A Training Guide for National Park Service Employees. National Park Service. http://www.ehs.ucsb.edu/files/docs/e
    h/ihrodentexclusion.pdf
  3. Simmons, S. 2005. Pest Prevention Construction Guidelines and Practices. CASBO Journal. http://www.cdpr.ca.gov/docs/pestmgt/pubs/casbo_article.pdf
  4. UMass Extension. 2008. Rodent Control on Farms. Fact Sheet – https://ag.umass.edu/sites/ag.umass.edu/files/fact-sheets/pdf/RodentControl08-44.pdf
  5. University of Maryland Extension. 2014. Rodent Control on Small Poultry Farms. Fact Sheet. https://extension.umd.edu/sites/default/files/_docs/publications/FS-
  6. 985%20Rodent%20control%20on%20small%20poultry%20farms.pdf
  7. Pierce, R. 1982. Bait Stations for Controlling Rats and Mice. Fact Sheet G-9444. University of Missouri Extension. http://extension.missouri.edu/p/G9444
  8. Vantassel, S. M., Hygnstrom S. E. and Ferraro, D. M. 2012. Bait Stations for Controlling Rats and Mice. Fact Sheet G1646. https://wildlife.unl.edu/pdfs/bait-stations-controlling-rats-mice.pdf.

Pumps and Pipes

A Taco 007
A Taco 007, shaken not stirred.

“Will the 007 be enough?”  is a common question in early spring as greenhouses around the region fire up and we do our best to keep seed trays and their cargo warm on the still-cool nights.  My mind instantly goes to “which movie?” And then I crash back to earth and realize this is a question about pumps and I am not Q. Continue reading Pumps and Pipes

Thermostats for Agriculture

I am often asked by growers and processors to recommend a thermostat for a greenhouse, cooler, or postharvest process use.  There are many to choose from and their specifications can be confusing. It is important to remember just what a thermostat does. It is essentially no different from the light switch on the wall with one very significant exception.  Instead of depending on a person to switch it from ON to OFF, we use a temperature measurement.  The accuracy of both the temperature setpoint (what you set) and the actual temperature (what the actual condition is) can be critical for production quality and energy efficiency. Continue reading Thermostats for Agriculture