SPECIALTY CROPS PROGRAM GROWER RESEARCH AND EDUCATION GRANT PROJECT REPORT PROJECT TITLE High tunnel strawberry production in suspended versus in-ground beds: can a suspended growing system be a profitable addition to the high tunnel? PROJECT SUMMARY Currently, there is increasing customer demand for and minimal production of fresh, local organically grown produce. Strawberries are a favored fruit throughout the country. Small-scale growers can take advantage of this high demand and low supply of local strawberries, especially in the off-season of late summer and autumn. The use of high tunnels can extend the strawberry growing season and improve yields (Rowley et al. 2010). We assessed the economic and logistic feasibility of increasing overall high tunnel production yields by adding a second level of growing; in other words, in addition to the typical method of growing in ground (i.e., raised bed production) we grew above ground (suspended growing system). Weeds are a major problem for in-ground strawberry production (Guerena and Born 2007); the suspended system was expected to have less weed pressure. Also, to increase yields, we used vermicompost, as recommended by Guerena and Born (2007), and created a small vermicompost in-ground bin, for growing this fertilizer; the vermicompost worms were supported by plant trimmings and bad fruit from the strawberry plants. The in-ground beds functioned as a baseline production rate, to which we compared production of the suspended system. Our hope was that the suspended system would prove profitable even if it yielded less fruit than the ground beds. PROJECT APPROACH Briefly summarize activities and tasks performed during the entire grant period. Whenever possible, describe the work accomplished in both quantitative and qualitative terms. Specifically, discuss the tasks provided in the Work Plan of the approved project proposal. Include the significant results, accomplishments, conclusions and recommendations. Include favorable or unusual developments. If the overall scope of the project benefitted commodities other than specialty crops, indicate how project staff insured that funds were used to solely enhance the competitiveness of specialty crops. Present the significant contributions and role of project partners in the project. 1 P age
On February 12, 2014, we were selected to receive full funding ($10,000) for a 2-year high tunnel strawberry research project. Upon receiving this grant, we immediately began to prepare the high tunnel for planting and growing. Work consisted of turning soil to a depth of 12 inches and shaping ground beds, hand removing well-established bindweed and associated roots (down to 12 inches), adding compost (organic mushroom compost, yard compost, and vermicompost), preparing suspended growing system, plumbing gutters and ground beds, ordering strawberry plants, installing a weed barrier to reduce bindweed pressure in ground beds, transplanting starts, creating datasheets and record keeping methods, and installing an in ground vermicompost system. Labor was provided by Rod Adams, Amy Yackel Adams, and Shauna Leibold. No fossil fueled equipment was used in the high tunnel. We established 4 ground beds (2.5 feet x 40 feet) and 5 lines of white gutters (suspended growing system) running 36 feet of the 48 foot high tunnel. We planted three varieties of day-neutral strawberries: Tribute, Seascape, and Tristar. Ground beds consisted of 1 bed of each of the varieties with the fourth bed being a mix of the 3 varieties in 3 distinct blocks. Similarly, suspended beds consisted of 1 line of each of the three varieties with the remaining 2 gutters being a mix of the 3 varieties in 3 distinct blocks. All plants were at 1 foot spacing. Once the strawberry plants were established, we tended plants biweekly to remove all flowers (first 6 weeks) and runners (throughout the growing season). We used a foliar spray of vermicompost tea on the starts for the first month (once per week). On 26 July 2014, we began a regular harvest of strawberries and maintained records on production in and above ground. Harvest ceased 9 November 2014, due to onset of freezing weather. We had considered using black plastic gutters in addition to white gutters. However, we abandoned the black ones early in the project because they warped from the heat of the sun which shrank the top opening. In place of black gutters, we hung 48 hanging baskets (16 baskets per strawberry variety) and used the opportunity to evaluate how soil volume might affect the overwintering of the plants, since the baskets provided more soil volume per plant than did the gutters. We suspect that the white gutters used in our system will be too shallow for overwintering the plants. Overheating of the high tunnel occurred on sunny days in July, with temperatures often exceeding 100 F within the tunnel. On 26 July, we installed Aluminet shade cloth (50% shading) fully across the top of the high tunnel and extending to about 4 feet above the ground. We also opened up both ends of the high tunnel for ventilation. On average, Aluminet helped reduce temperatures by 10 degrees. The growing substrate in the gutters worked well based on visual inspection of plants. The medium was a mix of ProMix BX, organic mushroom compost, vermicompost, and coconut fiber to enhance water retention. An unexpected problem from the suspended growing system was that the excess water emptied 2 P age
onto the ground beds below creating a nutrient uptake problem in those ground beds. Plants in those beds appeared to have iron chlorosis. This likely reduced overall production in the two beds directly beneath the gutters (Tristar and Seascape). On 11 October, we hosted an open house for students and the public. This event was sparsely attended. We have been contacted by several people that would like to attend the 2015 open house. This research was briefly mentioned in a news article by Libby James in the North Forty News this summer (21June2014) http://www.northfortynews.com/firefly-holistic-orchard-nurtured-to-life/ GOALS AND OUTCOMES ACHIEVED Describe the activities that were completed in order to achieve the performance goals and measurable outcomes identified in the approved project proposal or subsequent amendments. If outcome measures were long term, summarize the progress that has been made towards achievement. Provide a comparison of actual accomplishments with the goals established for the reporting period. Clearly convey completion of achieving outcomes by illustrating baseline data that has been gathered to date and showing the progress toward achieving set targets. Highlight the major successful outcomes of the project in quantifiable terms. All harvested berries from 26 July 2014 to 9 November 2014 were weighed, with weights recorded by variety and growing location to quantify production from ground and suspended beds for each of the 3 varieties (Table 1). We found that Seascape was the lead producing strawberry variety followed by Tribute, then Tristar. Yields from ground beds varied greatly, whereas suspended beds were more consistent in their output. Unexpectedly, per plant yields from the suspended growing system slightly exceeded that of ground beds for Tribute and Tristar (Table 2). Such a finding may be due to the reduced production of the ground beds directly beneath the gutters; the watering of the gutters caused excessive watering of the beds below. Overall, production of suspended beds (1.13) rivaled that of ground bed (1.23) production. Table 1. Total harvest weights for each strawberry variety (Tribute, Seascape, and Tristar) grown in ground and suspended beds at 1 foot spacing. Strawberry Variety Totals pounds Growing location Tribute Seascape Tristar Ground (n =111/variety ) 41.23 62.00 30.14 133.37 Suspended (n = 36.73 32.92 29.92 99.57 88/variety ) Totals 77.96 94.92 60.06 232.94 3 P age
Table 2. Overall yields (pounds per plant) for each strawberry variety (Tribute, Seascape, and Tristar) grown in ground and suspended beds at 1 foot spacing. Boldface indicates that overall yield per plant in a suspended system exceeds yields of ground production. Strawberry Variety Total pounds/plant Growing location Tribute Seascape Tristar Ground 0.37 0.59 0.27 1.23 Suspended 0.42 0.37 0.34 1.13 We conducted blind taste tests to evaluate flavor based on growing location. Participants were asked to provide a preference (if any) for three pairs of berries. Based on two separate trials (n trial 1 = 17 participants and n trial 2 = 10 participants) we found a slight overall preference for the taste of berries grown in the ground vs suspended (Table 3). This result was more pronounced during the second trial, possibly due to time in season. However, these differences were mostly subtle according to participants, and when asked in trial 1 if this would influence purchase, participants responded that it would not. Table 3. Blind taste test results for 3 varieties of strawberries grown in ground and suspended. Strawberry Variety Taste Preference Trial # 1 Totals 02 September 2014 Growing location Tribute Seascape Tristar Ground 7 9 7 23 Suspended 9 4 6 19 Equal 1 1 4 6 Total participants 17 14 17 Strawberry Variety Taste Preference Trial #2 Totals 11 October 2014 Growing location Tribute Seascape Tristar Ground 7 5 6 18 Suspended 0 4 3 7 Equal 3 1 1 5 Total participants 10 10 10 We conducted a blind test to evaluate appearance based on growing location. Based on one trial (n trial 1 = 13 participants) we found that participants showed a preference for Tribute (Table 4). This was affirmed during Trial 2. Participants associated the large beautiful berries of seascapes with the insipid berries found in grocery stores (berries that are grown for appearance that lack flavor [hard white middle]), even though the Seascapes had fully red, supple centers 4 P age
Table 4. Strawberry appearance results from Trial #1. Strawberry Variety Growing location Tribute Seascape Tristar Ground 4 3 2 Suspended 3 1 0 Totals 7 4 2 Weed pressure in the suspended growing system was absent. This resulted in a large saving of weeding labor. The ground beds needed weekly attention to suppress the bindweed. Hand pulling of bindweed was intense, at first requiring 2-3 hours/ week during March-July. Hand pulling was minimal after July. One of the main goals of the grant was achieved by quantifying production by weight. This research is ongoing. We will overwinter the plants and evaluate survival of plants in the two growing locations and will resume growing and harvesting strawberries in spring 2015. BENEFICIARIES Provide a description of the groups and other operations that benefited from the completion of this project s accomplishments. Clearly state the number of beneficiaries affected by the project s accomplishments and/or the potential economic impact of the project. This research is ongoing (year 1 of a two year project). Groups anticipated to benefit from these findings will be local growers, as it will help them know if it is profitable to grow in the unused space of a strawberry high tunnel. They will also benefit from learning of the problems we encountered and the success of our responses to those problems. Growers will also benefit from knowing that we sold 1 pound boxes of berries at $4.50 to our CSA members from July to November, and demand consistently outstripped supply throughout the season. LESSONS LEARNED Offer insights into the lessons learned by the project staff as a result of completing this project. This section is meant to illustrate the positive and negative results and conclusions for the project. Describe unexpected outcomes or results that were an effect of implementing this project. If goals or outcome measures were not achieved, identify and share the lessons learned to help others expedite problem-solving. 5 P age
Lessons learned should draw on positive experiences (i.e., good ideas that improve project efficiency or save money) and negative experiences (i.e., lessons learned about what did not go well and what needs to be changed). The gutter system needs a water catchment apparatus (tray to catch the water and send it down the lane to a water holding tank). Gutter style is important as the tops of our gutters bend inward making berry harvest cumbersome and reducing sunlight to berries growing on the soil surface. Gutters need to be on a pulley system so that they can be dropped to a lower level to facilitate harvest and then pulled up and out of the way after harvest. CONTACT PERSON Name the contact person for the Project (Telephone number and Email address) Rod Adams and Amy Yackel Adams at sunspot.urbanfarm@gmail.com ADDITIONAL INFORMATION Provide additional information available (i.e. publications, websites, photographs) that is not applicable to any of the prior sections. A photo journal of the Strawberry High Tunnel Research is provided below. 6 P age
Hand turning the rock-hard soil in the tunnel. Shauna Leibold hand-digging bindweed. This was a weekly task all summer long. 7 P age
Adding the compost to the ground beds. Close up of organic Hazel Dell Compost amendment. And yet another flush of bindweed. 8 P age
The native soil (soil clump to left) and the newly worked beds. Chickens assist with preparing the beds. 9 P age
Rod and Shauna prepare the mix for the suspended growing system the white gutters. The suspended growing system in place. 10 P age
Rod Adams cutting holes in the weed barrier for ground bed strawberries. A newly transplanted bed of Tribute strawberries. 11 P age
Shauna planting Seascape strawberries in the suspended growing system. A newly planted gutter of Tristar strawberries. 12 P age
s. Baskets used to replace black gutters (that warped from the sun at start of project). Vermicompost tea was applied the first several weeks as a foliar spray to young plants. 13 P age
We removed all flowers for the first 7 weeks after planting. The baskets with established plants. 14 P age
Ground and suspended growing system with established plants. Some of the first berries of the season. 15 P age
. Shauna harvesting berries. In the peak of the season this occurred 3 times per week. Berries were picked into labeled containers (by location and variety) and weighed. 16 P age
A 2 pound box of freshly picked Seascape strawberries ready for market. Overall view of the Strawberry High Tunnel. 17 P age