Post Harvest Handling & Storage for Small Farms

This presentation was given by Chris Callahan from at the Great Lakes Expo in Grand Rapids Michigan in December 2017. He discusses the differences between fruit and vegetable storage needs, finish surfaces for wash/pack areas or coolers as well as temperature and humidity controls.

 

A frequently asked question we get is about vapor barrier usage in coolers. See Chris’ answer below addressing that question. This video shot is pulled from the above presentation and was shared on our Instagram page.

New England Vegetable & Fruit Conference 2017

In addition to attending the Great Lakes Expo, UVM Ag Engineering attended the New England Vegetable & Fruit Conference in Manchester, NH. This conference is very well suited for the small-scale and highly diversified farmers that populate the North East.

This conference is filled with a variety of vendors at the trade show, presentations covering specific details of individual crops and varieties, and even talks on designing your farm with an eye on food safety. Another interesting activity that went on was the farmer to farmer sessions that are not presentations but a lead conversation to discuss what works and what doesn’t on your farm. A lot of tips, tricks, and common complaints are all brought up and shared during this literally circled up conversation.

If you’ve never been here are a few photos from the event, which was very snowy in mid-December.

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Here is a short highlight video from the conference!

 

The presentations that Chris gave at this conference can be seen below. This first one is all about designing your facilities with a food safety mindset. If you’ve never thought about your infrastructure Continue reading New England Vegetable & Fruit Conference 2017

Checking out Vendors at the Great Lakes Expo

In December, UVM Ag Engineering ventured out to Grand Rapids, MI to attend the Great Lakes Expo

This exposition was HUGE and full of a variety of seed companies, equipment suppliers, and machinery on display. There was a lot of technology targeted towards fruit growing which is big in that region which was neat to see.

Photos from the trip can be seen here.

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The following are videos clips taken with vendors explaining some of what they have to offer.

Continue reading Checking out Vendors at the Great Lakes Expo

Innovation in Small Scale Vegetable Washing Equipment

What’s new in Ag tech? Well, one thing that we’ve recently discovered is a rinse conveyor. Specifically designed for the small-scale farm who wants to graduate from hand washing to something a little more automated that can really crank up the pounds of washed vegetables for market.

The AZS Rinse Conveyor

This machine is made by AZS, an equipment manufacturing company in Ephrata, PA. It is available in full stainless steel, with adjustable water pressure and belt speed, available for under $7,000.

Continue reading Innovation in Small Scale Vegetable Washing Equipment

The AZS Rinse Conveyor at Native Son Farm

Native Son farm is a small diversified vegetable farm in Tupelo Mississippi, who had been washing vegetables by hand and started looking at automated wash lines. With zero experience on automated washing, he began first researching the common barrel washer, reading reviews, and watching videos online. Will Reed reached out to Deerfield Supply out Kentucky who distributed AZS equipment. Upon meeting Harvey from AZS, he learned about the rinse conveyor, which is less aggressive on the crops than a barrel washer. It is also designed with cleaning in mind which has a high level of food safety appeal.

Continue reading The AZS Rinse Conveyor at Native Son Farm

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

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.

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.

Finish Surfaces for Produce and Food Areas

This cooler space was finished with Trusscore PVC panels resulting in a smooth, cleanable surface.

Download an updated PDF version of this information here!

Smooth and cleanable surfaces are an important aspect of areas where produce is washed, packed, stored and processed.  Many farms are investing in renovations and expansions of these areas and are seeking materials to meet this “finish surface” need regardless of specific regulation.  Meanwhile, food processing companies are often required to incorporate these materials due to regulation.  This is a summary of some of the finish surface materials that are available, their pros, cons and pricing at this time.

 

Notes:

A properly outfitted cooler results in a clean install both visually, and physically. Note the use of trim pieces to close gaps at corners.
  • These are not necessarily compliant for food contact surfaces; they are meant to be finish materials for areas where food is being washed, packed or stored.  The general guidance is “smooth and cleanable.” Check with the appropriate local and/or state enforcement agency to confirm applicability to your project.
  • The prices listed are material cost only. The products differ in with regard to installation labor.  For example, flexible sheathing like FRP will require some sort of rigid wall material to mount to where as rigid panels such as Trusscore, Extrutech and Utilite can be installed on top of furring strips.  No installation costs have been captured in the prices listed.
  • Links to manufacturer info are included.  Most manufacturers sell via distribution channels.  Check with your local building supply company for availability and current pricing. As with most materials, higher volume purchasing generally results in lower unit costs.
  • The pricing on these materials is quite variable depending on the source, when you obtain a quote, the quantity being ordered and how it is delivered. The listed price is the best information available at the time of writing.  Shop around and obtain quotes from several distributors.
    Several manufacturer’s use panel locking mechanisms such as the tongue and groove system found in Trusscore. This provides for a smooth finish and hides the fasteners.

    Common shapes of available trim options to cover and seal all edges and seams. This keeps water from seeping behind the finish surface and entering the walls which can lead to molds and mildews and structural damage.
  • Most manufacturer webpages include an easy to find, specific, installation guide for their product that will be helpful in guiding installation.
  • FRP panels use H or J channel trim between pieces and corners which are calked in place to ensure a moisture proof seam. Follow the manufactures installation procedures.

    Ribcore 3’ or 9’ rib pattern options for ceilings

 

LED Lights – Status, Cost/Benefit and Pro’s and Cons

I have been receiving several inquiries recently on supplemental lighting for greenhouse production. The most common question is “Should I install LED lights to support growing?”
I have found one report to be the most complete and current on this topic and wanted to share it here.

Economic Analysis of Greenhouse Lighting: Light Emitting Diodes vs. High Intensity Discharge Fixtures by Jacob A. Nelson and Bruce Bugbee. Published: June 6, 2014. DOI: 10.1371/journal.pone.0099010. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0099010. Erik Runkle at Michigan State University also summarizes some of this work in Greenhouse Product News here.

There are some industry responses to this including this one from Inda-Grow. And a recent USDA report is somewhat contradictory in its findings here.

There is a also a nice summary by Robert Morrow in Hort Science (HortScience December 2008 vol. 43 no. 7 1947-1950) available here.

Nelson and Bugbee conclude;

The most efficient HPS and LED fixtures have equal efficiencies, but the initial capital cost per photon delivered from LED fixtures is five to ten times higher than HPS fixtures. The high capital cost means that the five-year cost of LED fixtures is more than double that of HPS fixtures. If widely spaced benches are a necessary part of a production system, LED fixtures can provide precision delivery of photons and our data indicate that they can be a more cost effective option for supplemental greenhouse lighting.

Manufacturers are working to improve all types of lighting technologies and the cost per photon will likely continue to decrease as new technologies, reduced prices, and improved reliability become available.

My take-away from all of this; LED’s have a higher initial cost, can have lower recurring costs, can be more effective for specific physiological benefit, and can support certain production layouts.  But the cost/benefit does not seem to pencil out quite yet.