Final report for FNE18-913
In this project we compared organic plasticulture strawberry systems and traditional organic matted row strawberry systems for June bearing varieties. The goal was to see if plasticulture systems were less expensive due to less weeding and cultivating, compared to matted row. We also wanted to see if we could manipulate the ripening season on the plastic beds to achieve ripening in the 2nd half of June (as our prior experience with plasticulture was that ripening always started earlier and ended earlier than matted row.) We had trials of plasticulture with different colored plastic mulches, different varieties, early removal of row cover, and delayed removal of straw mulch, all to see if we could delay ripening to provide ripe berries during the 2nd half of June and early July. We found that non of the treatments successfully shifted the ripening back to be comparable with matted row plantings. We also found that despite all the cultivating and weeding in the matted row system, the plasticulture system is more expensive to establish per acre. In the end we concluded that for our farm plasticulature plantings only make sense for extending the early ripening end of the strawberry season, and that maintaining significant matted row plantings are the best strategy for achieving the later June harvest window. We did however find several outstanding varieties that we were not previously familiar with that seem to be great yielders and outstanding flavor for the early plasticulture ripening window! We shared results of this research at a twilight meeting in June of 2019, and at well attended presentations at the the 600th New England Vegetable and Berry Growers Association winter meeting, NOFA NY winter conference and the NOFA VT winter conference in the winter of 19/20.
In this project we explored ways to modify the organic strawberry plasticulture system that would allow some of our strawberry acreage to ripen in later June & early July, but still maintain the weed control benefits of plasticulture. We trialed a combination of possibly later to ripen varieties combined with modifications of when row cover is removed, as well as several other strategies for manipulating the ripening timing of June bearing strawberry varieties. If successful, we were hoping this system would allow our farm and other New England & New York organic farms to move away from reliance on the hoe and hand weed intensive matted row strawberry production system. We theorized that this could save significant amounts of labor expense on these farms, but still yield plenty of strawberries in order to satisfy organic strawberry customers for the traditional full strawberry ripening season.
Strawberries are a sought out June sales driver at direct sales farms such as Red Fire Farm. We find that people will come out of their way during the strawberry season to visit our farm for strawberry pick your own, and we also find there is a strong demand for pre picked strawberries at our farmers market booths and farm stores in June, and also that our wholesale customers have a high demand for strawberries. However, we find that producing strawberries using certified organic practices is an expensive and challenging process. The biggest hurdle that makes it difficult and expensive to grow organic strawberries are the challenges with weed control that we routinely experience in our strawberry blocks. On our traditional matted row strawberry plantings we find that in addition to almost weekly cultivation, most blocks require extensive hoe & hand weeding efforts by large crews of farm workers on a 10 days schedule from May planting until Nov, and then we find that due to weed pressure it is only worth renovating and carrying plantings into a 2nd year of yielding less than half of the time. As an alternative, over the last five years we have been informally experimenting with overcoming these challenges by using a plasticulture plug based strawberry growing system on about ½ an acre of space each year. Using the varieties Chandler (& to a lesser extent Sweet Charlie & Camerosa) we have been able to achieve good yields on this plasticulture system using almost no handweeding or cultivation! However, the problem we are experiencing with our current plasticulture system is that it ripens berries starting earlier than the matted row plantings usually starting in the 2nd or 3rd week of May (which is great), but also these plantings wind down by mid June (typically three weeks before the matted row later season varieties typically end.) If we were to put more of our strawberry acreage into this plasticulture system, we would miss out on three weeks of prime strawberry season when our customers are expecting abundant strawberry availability (3rd & 4th weeks of June, and also the first week of July). We would like to find ways to grow organic strawberries (avoiding the fumigation & herbicides that are the crutch of conventional strawberry production), and also avoiding the excessive weeding that is the problem with organic matted row strawberry production, and achieving ripening of berries for the full late May into early July season. In particular we will seek ways to assure plenty of ripe berries in the 3rd & 4th weeks of June and the first week in July (which are the weeks not covered by the standard chandler based plasticulture system.)
What is your projects objectives?
In this project we would like to explore ways to modify the organic strawberry plasticulture system that will allow some of our strawberry acreage to ripen in later June & early July, but still maintain the weed control benefits of plasticulture. We will trial a combination of possibly later to ripen varieties combined with modifications of when row cover is removed, as well as several other strategies for manipulating the ripening timing of June bearing strawberry varieties. If successful, our farm and other New England & New York organic farms will be able to move away from reliance on the hoe and hand weed intensive matted row strawberry production system. This could save significant amounts of labor expense on these farms, but still yield plenty of strawberries in order to satisfy organic strawberry customers for the traditional full strawberry ripening season.
In business since 1995, Red Fire Farm is a diversified farm that grows organic vegetables, berries, cut flowers and greenhouse crops for CSA, retail &; wholesale markets. Approximately 100 acres of crops are planted each season on a land base of about 200 acres of crop land. The farm employees over 20 people year round with as many as 80 employees in the summer and fall. The farm has traditionally grown several acres of PYO strawberries for CSA and general public picking, as well as strawberries for wholesale harvesting. This research project was integrated into these plantings for the 2018 and 2019 seasons. The farm provided the equipment, land and general supplies needed to conduct these research trials.
- - Technical Advisor (Educator and Researcher)
In 2018 the blocks of strawberry plantings that are part of this research project were established. These blocks were planted on areas that had been free of strawberries for many years leading up to the experimental plantings, and also had been prepared with cover crops considered to be beneficial for strawberries (sorghum sudan, field peas or buckwheat). There were four plantings that were planted that are considered to be part of this research. In Montague the block called meadow 8 was planted to the matted row system using bare root plants on May 9th. Also planted in Montague was the pond 2&3 plasticulture blocks (with three different planting dates ranging from mid July, late Aug and Early Sept). In Granby the llf acre 13 field was planted to matted row on 5/11/18, and the Granby plasticulture block was planted onto pondside 3 with the same succession dates as the Montague plasticulture. (note, please don't get confused about the field names. Pond 2 & 3 are in Montague and are a completely separate field from pondside 3 in Granby. It is a coincidence that this study happened to rotate onto two fields with similar names.)
Bare root plantings were made of Chandler, Flavorfest, Jewel, and AC Valley Sunset on the Meadow 8 block on May 9th for the matted row trial beds, and in mid July for the bare root plastic beds.
Plug varieties were planted into the plastic beds on 8/24/18 (or early Sept for the plugs sourced from Canada and that arrived late.) The varieties Chandler, Flavorfest, Camino Real & Ruby June were purchased as tips from Goodson Farm (Balimore Farm), and then we rooted the tips under the mist system in our Montague greenhouse, and planted the plugs into the plastic beds in the last week of August. Chandler was planted on both black plastic, as well as silver and white plastic beds. Cleary CIV and Jewel we sourced as finished plugs from Nova Fruit in Canada, and they arrived about one week later than the plugs we grew, so these varieties we transplanted into the plastic beds around Sept 7th, as soon as we could once they arrived. The plug planted field space was able to stay in a summer cover crop of maturing oats and peas for an extra month compared to the mid July planted bare root beds, so this extra cover crop time is a side benefit of the plug planting system.
Beds for both the bare ground matted row block and for the plastic bed blocks were all planted at the same 69” from center to center spacing. The plastic beds are raised about 5”, and the flat top of the bed is approximately 36”. For the plastic beds, two rows per bed was planted with a between row spacing of 15”. In row spacing was 12”. The bare ground beds start with a 50" bed surface, and the bare root plants were planted with 1 row at the center of each bed with 12" in row spacing.
For the plasticulture beds, we installed woven black weed mat held down with ground staples, in order to cover all of the isle space between each plastic bed. This weed mat was installed shortly after the plants were planted, and effectively suppressed all wheel track and edge weeds.
On all plastic bed treatments, runners that the plants made in the summer and fall months were removed every 3 or 4 weeks (using knives or scissors). We also removed flower trusses from each of the bare root mother plants shortly after they formed (for both the matted row and plasticulture plantings). The plug started plants do not try to make any flowers in the first year.
Row cover was installed over all plastic bed plantings on 10/2/18. This row cover stayed in place throughout the fall and winter months. In the spring the cover was removed from half of each bed upon snow melt in the last week of March. On the other half of each bed the row cover stayed on until the plants begin to bloom. Also in early spring, upon removal of the row cover, a 50 foot section of Chandler on black plastic was covered with straw directly over the plants. This straw was be left in place until the 3rd week of April, after which point the straw was removed into the isle space (on top of the weed mat.) The idea was that this straw would keep the plants dormant longer, and thus delay blooming and fruiting.
The pond 2 & 3 plastic beds suffered some deer damage in Nov in 2018. The deer ripped holes in the row cover and ate leaves through the holes. As soon as this was discovered, we put on a new layer of row cover, and also installed electric deer fence around the perimeter of these blocks. The fence worked to keep the deer out for the rest of the winter, but damage did occur to some areas of the beds before we installed the fence. In the spring I selected areas of each treatment that appeared not to have deer damage, to use for the yield plots.
2019 was a cool spring, so even the earliest varieties with row cover treatments did not start ripening until the first week of June. We flagged 10 bed foot sections for each trial treatment and variety, and harvested each plot twice per week. Berries from each plot were weighed & recorded for each harvest day.
The matted row control block was grown using normal matted row methods. Cultivation, hoeing and handweeding was conducted about every 10 days all summer and into the fall. Mother plants were allowed to grow runners and set daughter plants, and rows were allowed to fill out to about 18" width. Straw mulch was applied on 11/27/18.
On June 20th as part of our Strawberry Soiree event, all berry varieties were entered into our annual strawberry taste test where customers rate flavor. This gave us an idea of customer preferences in terms of taste.
The Pondside 3 block in Granby was our first experience sending PYO customers into plastic covered strawberry fields (with no straw mulch.) We found that customers did not seem to mind as long as the berries were juicy and tasty.
For each of the four plantings all steps of planting and care of the plants were recorded, including the amount of labor spent on each job on each block, as well as the materials & supplies that went into each block. This data has been entered into a spreadsheet detailing the materials and costs spent on each block during the establishment year.
From the labor timing per task measurements, and from an analysis of materials & supplies used in each planting system, as well as assumptions for the time spent on each tractor pass, three enterprise budgets have been created for each of the three planting systems (comparing on a per acre basis). For now these enterprise budgets include only the first year establishment costs, and labor & supplies for harvest will be added after the 2019 harvest season data is collected for each system. These budgets do include assumptions for the labor & tractor work & supplies that will be needed after the crop cycle is over in order to clean up the fields and plant the space to cover crops (assumptions are based on general data for field clean up that we have established at Red Fire Farm over the years.)
The enterprise budgets show:
Matted Row System: 260 hrs of labor ($3905.25), 51.25 hrs of tractor time ($1435), and $3687 of plants and materials per acre, for a total cost of $9027 to do all steps other than harvest and marketing.
Bare Root Plasticulture System: 350 hrs of labor ($5255), 46.25 hrs of tractor time ($1295), and $5806 for plants and materials per acre, for a total cost of $12,356 to do all steps other than harvest and marketing.
Plug Plasticulture System: 302 hrs of labor ($4520), 46.25 hrs of tractor time ($1295), and $9359 for plants and materials per acre, for a total cost of $15,175 to do all steps other than harvest and marketing.
I am somewhat surprised that the significantly reduced weeding and hoeing needed in the plasticulture systems compared to the matted row system is not enough to outweigh the higher plant & supply costs of the plasticulture systems. The higher plant density and the cost per plant of plug plants in particular is the major factor that raises the cost of the plasticulture systems. Although cultivation and weeding on the matted row plantings is nearly constant all summer and into the fall, the time and expense of these activities is not as large as the extra density and more expensive plasticulture plugs. The labor on the plasticulture systems is also higher than the matted row systems due to the time it takes to install weed mat, and also runner removal. Clearly the yields will need to be significantly higher on the plasticulture systems in order to justify the higher per acre establishment costs of these systems. Yield measurements in 2019 will be critical to achieving a full understanding of the economics of each planting system.
Going into winter, all four fields look to be in reasonable condition with the exception of some patches in the pond 2 & 3 plasticulture block. This block suffered significant deer browsing during October and early Nov. The deer chewed through the row cover that was covering the plants at that time, and ate quite a few leaves. We installed electric deer fence around the field once it was discovered how bad the damage was. Not every part of every bed was impacted, but overall I expect some yield reduction in this block due to the deer damage that occurred. I believe that the plants were close to dormant when the damage happened, and for the most part the crowns of the strawberry plants were still intact, so hopefully yields will still be good. In the spring we will try to select the yield trial portions of the beds to measure from parts of each bed that did not have deer damage (provided we can tell which parts are which after the plants overwinter.)
Spreadsheet of data: SARE-Strawberry-project-yield-data
Enterprise budgets: strawb-enterprise-budgets-based-on-2018-actuals
In this project we learned a lot about what works and what doesn't when it comes to growing strawberries on our farm. In particular the detailed enterprise budget data that we collected on the three growing systems indicate that using a matted row system may actually be more ecenomical despite the amount of weeding work required. This was opposite of what I believed we would find prior to doing these trials. The extra expenses for plasticulture systems (more plants due to higher density, plastic mulch, ground cover, and runner removal) all add up to a more expensive establishment cost.
Additionally, in the end we did not successfully find a plasticulture based system that successfully shifted ripening of berries to the 2nd half of June. Even the later ripening varieties, silver and white mulch and delayed straw removal on the plastic beds did not result in the later season quantity and quality of ripe berries that compares with matted row quality and quantity for the 2nd half of June.
We did find that for the early half of the season (late May and Early June) the plasticulture varieties surpassed the early yield & quality of matted row berries for these weeks. We found several new stand out varieties that have excellent yields, quality & flavor (Cleary CIV & Camino Real in particular), and also were surprised at how well Jewel performed in plastic beds.
After doing this study we are going to continue to grow about 1/4 -1/3 of our strawberry acreage each season with the plasticulture system with a focus on early varieties and row cover to push the ripening season as early as possible. We are also taking measures to reduce costs in the plasticulture system (in particular cultivating out runners instead of hand cutting, and using hay mulch for weed control in isles instead of weed mat.) The rest of the acreage will continue to be matted row plantings with straw mulch. Before starting this research we were considering moving to only doing plasticulture strawberry plantings, but the research proved that this would not bring the benefits that we had hoped, and would in fact leave us short on berries to sell in later June and early July.
Education & Outreach Activities and Participation Summary
In June when strawberries were ripening that were part of this study a twilight meeting was held. This event did not draw a large crowd, but the approximately 15 people who attended did find this to be a useful tour, discussion and tasting of the different varieties. A brief handout explaining the project was made and distributed to attendees of this tour.
A power point presentation summarizing the findings of the research project was developed in Dec. I presented the first presentation to the 600th New England Vegetable and Berry Growers Association meeting on Jan 3rd 2020 in Hadley MA. This meeting was well attended with approximately 100 attendees, and the growers and extension people who saw the presentation seemed interested in the topic and project.
Two additional presentations were made based on the power point presentation in early 2020. One was at the NOFA NY winter conference on 1/19/20, and the second was at the NOFA VT conference on 2/15/20. Each presentation had about 25 farmers attend, and the presentations received good reviews from those in attendance.
-organic strawberry growing systems
-enterprise budgets for strawberries
-strawberry variety selection
-mulching options for strawberries
This project has not yet spun off into additional grants or research tangents, although this could happen in the future.
I have a much improved understanding of the economics of growing strawberries in both the matted row and plasticulture system. We are making some changes in how we manage the plasticulture patches in the future that should improve the economic equation.
We also discovered one standout variety that we had never before grown or heard of prior to this project (AC Cleary). We also trialed and now have experience and data with several other varieties that we had never before grown, and they are good enough that we are continuing plantings of those also in the future.
We did not succeed in extending the season of plasticulture ripening to match that of mid/late and late season matted row varieties. My final conclusion is that plasticulture may be a good solution for early and mid season strawberry production, but that including matted row patches in our yearly rotation will remain an important strategy for achieving main and late season harvest windows on our farm.
We learned that using silver and white mulch for strawberries does not seem worthwhile in our climate, as these treatments clearly reduced plant health & size, berry quality, and yield.
I believe that I have had success conveying the horticultural findings of this research to interested growers at the first presentation, and believe the upcoming organic conference presentations will also be effective to get this info out to additional interested strawberry growers.
I think that overall this study was effective and did answer questions that I set out to investigate about organic strawberry growing systems. The hardest part of the study was collecting the harvest data for the 29 different plots, as the staff assigned to this found it tedious.
I do plan to continue to promote annual plasticulture strawberry production as one option for organic strawberry growers to consider when choosing a system to use to produce berries. I now understand the pros and cons of the plasticulture vs matted row systems better than I did before embarking on this SARE project.
I believe that additional replicated variety trials of some of the varieties we looked at would be useful information for Northeastern growers. Although our trial was good, it only represented one season.
I think any strawberry growers in the Northeastern states could probably gain knowledgeable information by studying the results of this project, particularly those planing to use organic production methods.