Organic Apple Production In High Tunnels

Progress report for FNC20-1238

Project Type: Farmer/Rancher
Funds awarded in 2020: $9,000.00
Projected End Date: 01/31/2022
Grant Recipient: Two Onion Farm
Region: North Central
State: Wisconsin
Project Coordinator:
Expand All

Project Information

Description of operation:

My wife Juli and I have operated Two Onion Farm since 2003. From 2003-2017, we raised up to 5 acres of organic mixed vegetables. We have raised organic apples since 2012, and we now have two acres of apples outdoors (not in high tunnels) in addition to one-quarter acre each of currants and gooseberries. We transitioned our farm from vegetables to fruit to meet a strong market demand for local organic fruit and to protect our hillside soils from erosion with perennial crops. We market our apples through a community-supported agriculture (CSA) program, to local grocery stores and chefs, and by processing them into applesauce and apple butter.

We raise trellised dwarf trees in our outdoor apple orchard. We grow disease-resistant varieties which require minimal organic sprays. We use bark mulch under our trees to reduce weed competition, supply nutrients and organic matter, and nourish beneficial soil fungi. We encourage beneficial insects in the orchard, scout daily for pests, monitor weather to predict pest outbreaks, and only spray organic pesticides as a last resort.

We constructed our first high tunnel in 2011 and currently have three high tunnels on our farm. In two previous years we raised nursery apple trees in high tunnels (these were grafts raised for one year in the high tunnel before being dug and transplanted to a permanent location). We were impressed by the vigorous growth and the absence of disease in these high tunnel nurseries; this motivated us to consider growing apples permanently inside tunnels.

Our farm infrastructure includes a packing shed, three walk-in coolers, and two tractors with implements for tillage, cultivation, mowing, spraying, and spreading amendments.

Summary:

Locally produced organic apples are in demand, but most organic apples are produced in desert areas of Washington, where the dry climate reduces infection from fungal diseases such as apple scab.  In the north central U.S., wetter weather favors disease, and most organic apple growers grow disease-resistant varieties and/or spray organic fungicides such as sulfur.  Disease-resistant varieties can be difficult to market if they are not the most flavorful varieties or if they are not familiar to consumers.   Organic fungicide sprays are expensive, require frequent re-application, and can have negative effects on apple trees, beneficial insects, and the environment.  I propose to evaluate the profitability of organic apples grown in unheated polyethylene-covered high tunnels.  Trees in tunnels are protected from rain and should therefore suffer less disease.  Tunnels can also ameliorate severe weather, provide better growing conditions, and thus improve yields.  Although high tunnels are expensive to build, many growers already have tunnels or can construct them at low cost with USDA-NRCS EQIP grants.  I will compare seven apple varieties in our project: high tunnels may be best suited to disease-susceptible varieties which are difficult to grow outdoors but which command a high market price.

Project Objectives:
  1. Measure costs, yields, and profitability of organic apples raised in high tunnels.
  2. Compare yields and profitability of seven apple varieties in high tunnels.
  3. Measure incidence of common apple diseases and insect pests in high tunnels.
  4. Share results with other growers through our website, field days, emails to grower list-serves, articles in grower publications, and a conference poster session.

Research

Materials and methods:

We established the high tunnel plantings in April 2019 and we will collect data through the end of this project in January 2022.  (Some of the activities described here occurred before the start of the grant project period and were not funded by the grant, but we are including them here to give a complete context for the project).

Planting Arrangement.  There are thirteen trees of each variety in each tunnel, along with 1-2 border trees at each end of each row.  (Border trees will not be included in statistical comparisons of varieties).  Within each tunnel, the 91 non-border trees are arranged randomly, with varieties randomly interspersed to permit statistical comparisons of yield.  Trees are planted 3' apart within the row.

Planting high tunnel apples

Varieties.  We selected seven apple varieties for this study: Ashmead’s Kernal, Grimes Golden, Macoun, Hudson’s Golden Gem, and Golden Russet are rare heirloom varieties which command a high price because of their flavor and historical interest.  However, all are susceptible to scab and other diseases and we therefore do not raise them outdoors.  The other two varieties, Winecrisp and Suncrisp, are high-yielding modern varieties popular with local organic growers.  We have raised these varieties outdoors.  We included them as a comparison to the five heirloom varieties because they are reliable standards and because they are heat-tolerant and thus may thrive in warm high tunnels.

High Tunnels.  Two high tunnels are used in this study; both allow trees to reach heights of 10+′ and are ventilated via rollup sides and endwall doors:

Tunnel Width Length Number of Tree Rows Trees Per Row Total Trees Border Trees1 Experimental Trees2 Year Constructed Initial Construction Cost (Materials Only)
1 34' 102' 3 33 99 8 91 2017 $9,643
2 24' 148' 2 49 98 7 91 2018 $9,955

1Border Trees are at the ends of rows; no data was collected from these trees
2Experimental Trees are the trees from which data was collected

High Tunnel Coverings.  When the trees were planted in April 2019, the tunnels were covered with a single layer of standard greenhouse polyethylene.  We removed the plastic prior to winter (on 10/25/2019 from tunnel 1, and on 12/5/2019 from tunnel 2).  Based on the experience of farmers and researchers with other tree fruits, it is important to not expose trees to the drastic diurnal temperature fluctuations that occur in winter in high tunnels covered with clear greenhouse polyethylene.  On sunny days, temperatures can rise steeply in tunnels covered with clear plastic, but at night the temperatures inside the tunnel are similar to outdoor temperatures.  Trees cannot remain cold-hardy and acclimated under these constant temperature swings and are likely to suffer cold damage at night.  In spring 2020, we covered both tunnels using a single layer of Klerks SunView Cool polyethylene, which lowers tunnel temperatures by approximately 10 degrees compared to the traditional polyethylene covers (tunnel 1 was covered on 5/2/2020, and tunnel 2 on 5/6/2020).  We selected the SunView Cool cover because the trees suffered leaf burn during warm spells in 2019 and because apple fruits are vulnerable to sunburn at air temperatures above 95 degrees.  For the winter of 2020-21, we elected not to uncover the tunnels because of the time required, the stress and difficulty of covering tunnels during windy early spring weather, and the risk of damaging the cover during removal and reinstallation.  Instead, on 11/23/2020 we covered both tunnels with Film-Gard black and white 5 mil silage tarp.  The tarp was installed white side out, and completely covered the south, east, and west sides of each tunnel, preventing winter sunlight from entering the tunnel.  We had heard from other growers who raise stone fruits in high tunnels that the silage tarp keeps the tunnel cool in winter and prevents daytime temperature spikes.  The silage tarp will be removed in spring 2021.

Tunnel 1 covered with silage tarp

For ventilation, rollup sidewalls and endwall doors were regularly left open during the growing season.  Before mid July, we attempted to close the tunnels during rain to minimize the chance that windblown rain would wet foliage and lead to disease.  Later in summer and in fall we no longer closed the tunnels.

Tree Planting.  The trees planted were one year old grafts raised in our on-farm nursery or purchased from Cummins Nursery, Trumansburg, NY. We planted trees on April 12th and 17th, 2019. 

Mulch and Weed Control.  We completely covered the soil surface in both tunnel with hardwood bark purchased from local sawmills after planting.  Tunnel 1 was mulched in May 2019, but Tunnel 2 was not mulched until November 2019 because of time constraints.  Both tunnels were hand weeded as needed during the growing seasons.

Mulched trees, early summer 2020

Irrigation.  Both tunnels were irrigated using drip tape with a flow rate of 0.34 GPM per 100'.  Irrigation sessions were generally for 8-12 hours on 4-7 day intervals, depending on weather.

Training.  In the 2019 growing season, we trained trees on a minimal wire trellis suspended from the high tunnel structure.  Trees were secured to the wires with tree tie tape, and vigorous branches were tied below horizontal using training wires.  Trees are 3′ apart within rows, grafted on dwarfing rootstocks (G. 41 or G.11) and trained using the tall spindle method; these are common practices in outdoor high-density apple orchards.  To encourage branching, we notched the cambium above dormant buds on the leader in both years (4/22-4/29/2019, around green tip; and 5/5-5/8/2020, just before bloom).  In April, 2020 we installed a permanent support stake next to each tree (Best Angle Tree Stake model PA3120 - 10' high angle iron stake 1-1/4" x 1-1/4"); stakes were pounded 2.5' into the ground, with 7.5' above ground.  We secured trees to the stakes with AgLok chain and continued to train vigorous branches below horizontal using training wires.

Young branches trained downward with training wires

Thinning.  In 2019, we removed any developing fruit after bloom.  In 2020, we hand-thinned fruits, aiming for 1-3 (occasionally 4) fruits per branch, depending on branch length, and 1-4 additional fruits on the leader.

Pest Control and Nutrient Sprays.  We scouted each high tunnel weekly for disease and insect pests.  Sprays were applied using a Rears Pakblast 50 tractor mounted airblast sprayer, except for safer soap which was spot-sprayed on aphid-infested foliage.  In addition we installed delta traps baited with pheromone lures for codling moth, red-banded leafroller, and oblique-banded leafroller in tunnel 1.  In general, we made no disease controls sprays.  We sprayed micronutrients on the same schedule as used for outdoor apple plantings.  We sprayed insect control products at several times.  All sprays are shown in the table below.  The high tunnel plantings were certified organic and all sprays were organically approved.

Date Product and rate
05-Apr-20 JMS Organic Stylet Oil 1 Quart per 100 gallons spray per acre
20-Apr-20 Clean Manganese 1 Quart per 50 gallons spray per acre
20-Apr-20 Clean Zinc 1 Quart per 50 gallons spray per acre
20-Apr-20 Clean Iron 2 Cup per 50 gallons spray per acre
20-Apr-20 Clean Symspray 0-0-1 1 Cup per 50 gallons spray per acre
20-Apr-20 Clean Copper 2 Cup per 50 gallons spray per acre
20-Apr-20 Clean Calcium 1 Quart per 50 gallons spray per acre
03-May-20 Dipel 2 Lb per 50 gallons spray per acre
03-May-20 Clean Calcium 2 Quart per 50 gallons spray per acre
03-May-20 Clean Manganese 1 Quart per 50 gallons spray per acre
03-May-20 Clean Symspray 0-0-1 1 Cup per 50 gallons spray per acre
03-May-20 Regalia 4 Cup per 50 gallons spray per acre
07-May-20 Clean Potassium 0-0-6 6 Quart per 50 gallons spray per acre
21-May-20 Regalia 4 Cup per 50 gallons spray per acre
21-May-20 Clean Symspray 0-0-1 2 Cup per 50 gallons spray per acre
21-May-20 Dipel 2 Lb per 50 gallons spray per acre
21-May-20 Lifegard 4 Oz per 50 gallons spray per acre
21-May-20 Clean Calcium 2 Quart per 50 gallons spray per acre
31-May-20 Clean Iron 4 Cup per 50 gallons spray per acre
31-May-20 Clean Manganese 1 Quart per 50 gallons spray per acre
31-May-20 Clean Calcium 2 Quart per 50 gallons spray per acre
31-May-20 Kinetic Nonionic Surfactant and Silicone Surfactant Blend 3 Fl oz per 25 gallons spray per acre
31-May-20 Sil-Matrix 1 Quart per 25 gallons spray per acre
31-May-20 Clean Symspray 0-0-1 1 Cup per 50 gallons spray per acre
03-Jun-20 Citric Acid 12.5 Fl oz per 50 gallons spray per acre
03-Jun-20 Pyganic 15 Cup per 60 gallons spray per acre
06-Jun-20 Citric Acid 4 Fl oz per 100 gallons spray per acre
06-Jun-20 JMS Organic Stylet Oil 4 Quart per 100 gallons spray per acre
06-Jun-20 Clean Calcium 4 Quart per 100 gallons spray per acre
06-Jun-20 Azaguard 2 Cup per 100 gallons spray per acre
08-Jun-20 Pyganic 15 Cup per 50 gallons spray per acre
08-Jun-20 Citric Acid 15 Fl oz per 50 gallons spray per acre
12-Jun-20 Azaguard 2 Cup per 100 gallons spray per acre
12-Jun-20 Citric Acid 4 Fl oz per 100 gallons spray per acre
12-Jun-20 JMS Organic Stylet Oil 4 Quart per 100 gallons spray per acre
14-Jun-20 Clean Calcium 4 Quart per 100 gallons spray per acre
17-Jun-20 Molasses 3.33 Cup per 50 gallons spray per acre
17-Jun-20 Madex 1.25 Fl oz per 50 gallons spray per acre
21-Jun-20 Clean Calcium 4 Quart per 100 gallons spray per acre
21-Jun-20 Clean Manganese 1 Quart per 100 gallons spray per acre
21-Jun-20 Clean Zinc 1 Quart per 100 gallons spray per acre
23-Jun-20 Dipel 2 Lb per 100 gallons spray per acre
23-Jun-20 Madex 1.5 Fl oz per 100 gallons spray per acre
23-Jun-20 Molasses 4 Cup per 100 gallons spray per acre
23-Jun-20 Surround 50 Lb per 100 gallons spray per acre
25-Jun-20 JMS Organic Stylet Oil 4 Quart per 100 gallons spray per acre
25-Jun-20 Azaguard 2 Cup per 100 gallons spray per acre
25-Jun-20 Citric Acid 4 Fl oz per 100 gallons spray per acre
28-Jun-20 Clean Calcium 4 Quart per 100 gallons spray per acre
29-Jun-20 Sil-Matrix 4 Quart per 100 gallons spray per acre
29-Jun-20 Madex 1.5 Fl oz per 100 gallons spray per acre
29-Jun-20 Dipel 2 Lb per 100 gallons spray per acre
29-Jun-20 Kinetic Nonionic Surfactant and Silicone Surfactant Blend 8 Fl oz per 100 gallons spray per acre
02-Jul-20 JMS Organic Stylet Oil 4 Quart per 100 gallons spray per acre
02-Jul-20 Azaguard 2 Cup per 100 gallons spray per acre
02-Jul-20 Citric Acid 2 Fl oz per 100 gallons spray per acre
05-Jul-20 Clean Calcium 4 Quart per 100 gallons spray per acre
05-Jul-20 Dipel 2 Lb per 100 gallons spray per acre
08-Jul-20 Madex 1.40625 Fl oz per 50 gallons spray per acre
08-Jul-20 Molasses 3.75 Cup per 50 gallons spray per acre
12-Jul-20 Citric Acid 3 Fl oz per 100 gallons spray per acre
12-Jul-20 JMS Organic Stylet Oil 4 Quart per 100 gallons spray per acre
12-Jul-20 Azaguard 2 Cup per 100 gallons spray per acre
17-Jul-20 JMS Organic Stylet Oil 4 Quart per 100 gallons spray per acre
17-Jul-20 Citric Acid 3 Fl oz per 100 gallons spray per acre
17-Jul-20 Azaguard 2 Cup per 100 gallons spray per acre
20-Jul-20 BeetleGone 2.5 Lb per 100 gallons spray per acre
20-Jul-20 Clean Calcium 4 Quart per 100 gallons spray per acre
20-Jul-20 Dipel 2 Lb per 100 gallons spray per acre
20-Jul-20 Clean Manganese 2 Quart per 100 gallons spray per acre
29-Jul-20 Dipel 2 Lb per 100 gallons spray per acre
29-Jul-20 Azaguard 2 Cup per 100 gallons spray per acre
29-Jul-20 JMS Organic Stylet Oil 4 Quart per 100 gallons spray per acre
29-Jul-20 Citric Acid 3 Fl oz per 100 gallons spray per acre
30-Jul-20 Clean Manganese 2 Quart per 100 gallons spray per acre
30-Jul-20 BeetleGone 2.5 Lb per 100 gallons spray per acre
30-Jul-20 Venerate XC 2 Quart per 100 gallons spray per acre
30-Jul-20 Dipel 2 Lb per 100 gallons spray per acre
30-Jul-20 Clean Calcium 4 Quart per 100 gallons spray per acre
07-Aug-20 Kinetic Nonionic Surfactant and Silicone Surfactant Blend 8 Fl oz per 100 gallons spray per acre
07-Aug-20 Sil-Matrix 4 Quart per 100 gallons spray per acre
09-Aug-20 Clean Calcium 4 Quart per 100 gallons spray per acre
09-Aug-20 Madex 1 Fl oz per 100 gallons spray per acre
09-Aug-20 Venerate XC 2 Quart per 100 gallons spray per acre
09-Aug-20 Dipel 1 Lb per 100 gallons spray per acre
09-Aug-20 BeetleGone 0.9375 Lb per 100 gallons spray per acre
09-Aug-20 Molasses 4 Cup per 100 gallons spray per acre
21-Aug-20 Clean Calcium 4 Quart per 100 gallons spray per acre
21-Aug-20 Venerate XC 2 Quart per 100 gallons spray per acre
21-Aug-20 Madex 1 Fl oz per 100 gallons spray per acre
21-Aug-20 Molasses 4 Cup per 100 gallons spray per acre
30-Aug-20 Madex 1 Fl oz per 100 gallons spray per acre
30-Aug-20 Molasses 4 Cup per 100 gallons spray per acre
30-Aug-20 Venerate XC 2 Quart per 100 gallons spray per acre
30-Aug-20 Clean Calcium 4 Quart per 100 gallons spray per acre
30-Aug-20 Dipel 1 Lb per 100 gallons spray per acre

Pollination.  A Koppert Natupol Excel Startup bumblee colony was placed in each tunnel on 5/7/2020 to ensure adequate pollination. 

Research results and discussion:

Trellising and training.  In general, vegetative vigor was high, and we were somewhat concerned that the trees might outgrow their space over time.  Most leaders were close to the roof of the high tunnel by the end of 2020.  Repeated rounds of branch training were required in both 2019 and 2020.  The variety Suncrisp was particularly troublesome because of its propensity to grow strong upright branches.  We were pleased with the success of notching the leader in both years, which resulted in good branch development and little blind wood on the leader.

Spring bloom and pollination.  In 2020, high tunnel trees bloomed synchronously with field-grown trees, with first flowers opening on 5/12-5/13.  (Note, however, that the tunnels were uncovered 5/2-5/6).  Nighttime temperatures in our outdoor orchard reached 28 degrees F on the morning of 5/9, shortly before bloom and when flower buds were very susceptible to cold damage.  We found no damage to flowers in the field orchard from this cold event.  However, king blooms on most high tunnel varieties were killed (pistils were blackened).  In addition most Macoun fruits in the high tunnel which did develop showed blossom end russeting which is commonly associated with frost damage at bloom.  We did not have a thermometer in the tunnels but we suspect that the freeze event was actually more severe in the tunnel than outside.  Other high tunnel growers in our region have noted that nighttime temperatures can actually be lower in tunnels than outdoors. 

Frost damaged flower

We noticed that bumblebee workers from the introduced colonies regularly foraged outside the tunnel, and appeared to actually prefer foraging in the nearby outdoor field orchard.  However, bee activity was high inside the tunnels on rainy days.  Overall, fruitset was high and pollination appears to have been adequate.

Harvest and Yield. The table below shows total yields from both tunnels in 2020:

Grade Total Yield of Saleable Fruit from High Tunnels (Lbs) Average Price Received By Our Farm For Fruits of This Grade Value of High Tunnel Fruit
#1 788 $2.54 $2001
#2 451 $1.09 $492
Total 1239   $2493
Total per tree 6.81   $13.70

Some general trends were noted on fruit of many varieties: 

  • Most fruit were exceptionally sweet - sweeter than would be expected on same varieties grown in field. In some cases, this was accompanied by an aldehyde-type flavor which some eaters found unpleasant.  This off-flavor diminished in storage to some extent.
  • Watercore was common on some varieties
  • Some varieties showed symptoms of sunburn. 
  • In general, red skin color was less than would be expected in field-grown apples. 
Variety Harvest Dates Yield Per Tree High Tunnel 1 (Lbs) Yield Per Tree High Tunnel 2 (Lbs) Percent of fruits which were #1 grade Notes
Ashmead's Kernal 9/22 0.3 1.0 n/a Heavy russeting, bitter pit developed in storage.  Sun=exposed fruits sometimes had black rotting areas on exposed side of fruit.  Exceptional flavor, high sugar, moderate acid.
Golden Russet 9/22 6.1 9.2 93% Little or no russeting.  Sunburn and underlying soft flesh common on sun-exposed fruits.  Watercore common.  Otherwise quality good.  High sugar, moderate acid.
Grimes Golden 10/9 5.5 15.2 66% Large size, excellent appearance.  Sunburn and underlying soft flesh common on sun-exposed fruits.  Generally soft flesh.  High sugar, low acid.  Unpopular with consumers because of soft flesh.  Most #2 grade fruits were overripe and/or had sunburn.
Hudson's Golden Gem 10/7-10/8 0 3.2 n/a Set many fruit, but most dropped in June.  Moderate russeting.  Some watercore, but otherwise fruit quality, texture, and flavor exceptional.  High sugar, low acid.
Macoun 10/7-10/8 1.6 7.2 0% Very soft texture (unsaleable), pale green color.  Blossom end russeting from frost damage before bloom.  Tart.
Suncrisp 10/7-10/8 18.6 17.5 61% Large size, excellent appearance.  Slight watercore.  Strong tropical or banana flavor.  High sugar, moderate acid.  Popular with consumers and grocery store buyers.  Most #2 grade fruits had sunburn or evident watercore.
Winecrisp 10/7-10/8 3.3 6.6 74% Large size, excellent appearance.  High sugar.  Most #2 grade fruits had sunburn or evident watercore.

 

Hudson's Golden Gem with russeting

Disease.  Virtually no signs of plant disease were noted in the tunnels. A few cedar apple rust lesions occurred on early spur leaves of Golden Russet and Hudson's Golden Gem; it is likely that these infections may have occurred shortly before the tunnels were covered in early May. Fireblight, scab, alternaria blotch, sooty blotch and flyspeck were all absent or extremely rare.  The virtually pristine foliage, even in mid to late autumn, was remarkable.

Insect Damage.  In general, low to moderate insect damage was observed in the tunnels. 

Rosy apple aphid infestation
  • Rosy apple aphid infestation occurred in both tunnels in late May and June.  These aphids rarely if ever cause significant damage in our outdoor orchard.  The infestations were controlled by localized spraying of Safer soap (1 tsp/1 cup water) with a hand spray bottle.  In several cases, the aphid infestation grew to significant size before we noticed it and multiple time-consuming sprays were needed to eradicate the aphids, showing the importance of timely scouting for this pest.
  • Plum curculio oviposition damage was found in tunnel #2 on June 9th, at which time it was estimated to be about one week old.  Approximately 10 damaged fruits were found.  This is a low level of damage; no further damage was seen.  Note that Pyganic was sprayed in both tunnels on June 3rd and 8th to kill this insect.  This insect is regular in our field orchard, where low-moderate levels of damage are seen every year and we spray Surround kaolin clay for control.  We opted not to spray Surround in the tunnels out of concern that the residue would not wash off before harvest without rainfall.
  • No Japanese Beetle damage was noted, although this insect is fairly common in our outdoor orchard.  Note that we did spray AzaGuard in July several times, which has moderate deterrent effect on this insect, and we sprayed beetleGONE once on 7/30; this bacterial insecticide is extremely deadly to the insect.  Nevertheless, the low level of Japanese Beetle damage was notable given that we see damage in our field orchard every year even when these products are sprayed more frequently.
  • Starting on June 10th, spider mite damage to foliage was evident in tunnel 1.  Because our previous experience had showed that this insect can severely damage high tunnel nursery apples, we sprayed JMS Stylet Oil (horticultural oil) regularly during the remainder of the growing season.  Low levels of damage continued throughout the summer in the same area.  Spider mites are not a pest in our outdoor orchard, and they are presumably favored by the dry conditions within the high tunnel.
  • In pheromone-baited traps within tunnel 1, we trapped red-banded leafroller (RBLR) regularly during summer flights and we also trapped 4 oblique-banded leafrollers from June 12-20.  Because our previous experience had showed that leafrollers and other caterpillars can significantly damage high tunnel nursery apples, we sprayed Dipel (Bacillus thuringiensis) during the growing season.  Occasional but not significant damage to shoot terminals from leafrollers was seen.  These insects are consistent pests in our outdoor orchard.
  • No codling moths were caught in the pheromone-baited traps within tunnel 1.  Codling moth is a major pest in our outdoor orchard, although we are able to achieve good control there with a combination of mating disruption and granulosis virus sprays.  Because this pest is so devastating, we did spray Madex (granulosis virus) in the high tunnels during first and second generation egg hatch, as predicted by trap counts from our outdoor orchard.  No damage was seen in the high tunnels.

Labor Time.  The following table shows labor time (hours) per year for various work tasks for the 182 experimental trees.  The most time-consuming task was to trellis and train the trees, which primarily reflects the time needed to construct the trellis and perform regular branch training.

Work Task 2019 2020
Plant fruits 43.9 0.0
Irrigation (apply and set up) 5.4 6.1
Mulch with hardwood bark 10.4 0.0
Seasonal covering/uncovering 11.6 19.0
Install rodent guards 2.2 0.0
Spray pesticide 7.4 16.0
Trellis and train trees 60.3 90.2
Weed 23.1 10.9
Thin fruits 0.0 14.4
Pick up fruit drops 0.0 3.4
Harvest 0.0 7.3
Wash fruit 0.0 4.0
Total 164.1 171.4
Total per tree 1.69 1.77

Expenses. The following table shows costs per experimental tree incurred in 2019 and 2020.  Cost of constructing the high tunnel structure are not included.  As of the end of the second season, a total cost per tree of $99.21 has been incurred.  This includes labor priced at $15 per hour, and labor accounts for approximately half the total cost..  The value of fruit harvested per tree has been $13.71. 

Item 2019 2020 Notes
Mulch $4.81   $13.13 per yard
Trellis stakes   $7.16 $7.16 each
Trellis and training supplies $0.77 $0.77 Close estimate of materials used: $0.32 for AgLok chain, $0.93 for 24" wire ties, $0.29 for 12.5 ga high tensile wire for trellis)
Trees $19.84   Average price per tree of trees purchased from commercial nursery in 2019
Sprays   $2.04  
Labor $25.35 $26.55 $15 per hour
Bumblebee colonies   $1.61  
Klerks koolite plastic   $6.56 Plastic should last for three-four growing seasons
Silage tarp   $3.76 We expect that tarp will last for several growing seasons
Total cost per tree $50.77 $48.44  

 

Participation Summary
1 Farmer participating in research

Educational & Outreach Activities

1 Curricula, factsheets or educational tools
1 Workshop field days

Participation Summary:

20 Farmers
1 Ag professionals participated
Education/outreach description:

Outreach completed as of 12/2/2020:

We hosted a field day at our farm, sponsored by CRAFT Angelic Learning Center, on July 14, 2020.  There were 18 attendees.  Although it was early in this project, we used the opportunity to speak about the progress of this project and distributed a handout describing our experiment and results to date: Field Day Handout July 2020.  Ten attendees provided their email addresses and asked to receive a final summary of the project.

Additional outreach is planned for December 2020- February 2021:

July 2021 At a fruit production field day at our farm, distribute handout describing research methods and results to date and tour high tunnel plantings.  Collect contact information from attendees.  Expect 30+ attendees at each field day. 
November 2021 Analyze data and write summary of project results.  Post summary on farm website and distribute at subsequent outreach activities.
December 2021 Email summary of results to attendees at previous field days and relevant email list-serves: Apple-Crop (over 500 participants), Fairshare Google Group (over 300 participants), and Organic Fruit Growers (over 350 participants).
December 2021 Submit articles summarizing project for publication in Just Picked, the newsletter of the Organic Fruit Growers Association (over 425 readers), and Wisconsin Fruit News (approximately 1000 readers).  Publication is not certain, but I have previously authored articles for both publications.
December 2021 Apply to present results in research poster session at the December 2021 Great Lakes Fruit, Vegetable, and Farm Market EXPO in Grand Rapids, MI (over 4000 attendees).  If accepted, present results there and collect contact information from interested poster viewers. 
January 2022 Submit press releases summarizing research results to national fruit grower periodicals: Good Fruit Grower, Fruit Growers News, and American Fruit Grower.  Publication is not certain, but these magazines have previously printed articles describing other on-farm research projects.  All three magazines are widely read by commercial fruit growers.
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.