Project Overview
Commodities
- Fruits: berries (strawberries)
Practices
- Crop Production: high tunnels or hoop houses
- Soil Management: composting
Proposal abstract:
This project is a site-specific evaluation of tabletop hydroponic strawberry production systems as an economically feasible tool for local strawberry production in low-cost high tunnels. We are proposing to install tabletop production systems under the existing caterpillar tunnel at Everoak Farm. Strawberry plants will be grown in troughs which will sit in gutters raised several feet off the ground, about waist height, which is so-called “tabletop.” This system will produce clean fruit that will be harvested quickly and easily. It can be installed on marginal land that would not normally be used for agriculture. Our farm cooperator Mike Garcia is super interested in trialing the high-value tabletop strawberry production system with us as he is new to strawberry production and does not have a large acreage dedicated to strawberry production, while he is trying to meet a high consumer demand for fresh and tasty local strawberries.
In terms of selecting appropriate growth media, we are proposing to use locally produced composts as potential growth substrates for conducting tabletop hydroponic strawberry production at Everoak Farm. Growing media is one of the most important factors that determine the overall development and performance of the strawberry plants. Appropriate growing media should have a good ability to hold water and nutrients while providing good aeration to the root system. The ideal media should also be lightweight and free of harmful organisms and hazardous compounds for plants (Imran et al., 2022). Several important physical and chemical properties including bulk density (BD), total porosity (TP), water holding capacity (WHC), pH, electrical conductivity (EC), organic matter (OM), total carbon (C), nitrogen (N) and other essential nutrients such as potassium (K), magnesium (Mg), iron (Fe), manganese (Mn) and calcium (Ca) should be analyzed before designing the tabletop hydroponic system. After visits to and discussions with local compost and organic mulch facilities in Florida, we were able to identify several potential substrate candidates for evaluation in this project such as green waste compost and composts derived from animal manure and yard wastes, as well as locally available pine bark and palm fiber. There is one unique opportunity for us to test the bagasse and mill mud compost, which is a novel product that is being developed to recycle the organic waste from the sugarcane industry in South Florida.
Based on the results of our preliminary studies (unpublished data) and continued discussions with the farm cooperator, we are proposing to test three different types of potential substrates in this study that involve ingredients of composted yard waste, on-farm compost created by the farm cooperator at Everoak Farm, vermicompost, and bagasse and mill mud compost, including possible mixtures. Testing the on-farm compost produced at Everoak Farm is suggested by our farm cooperator Mike Garcia. Bagasse and mill mud compost may be a beneficial, locally available option as it helps to manage and dispose of organic wastes from the large sugarcane industry in Florida. Available nutrient contents of the compost-based growing media will also be measured over the entire strawberry production season since we want to quantify any contribution to nutrient (especially N, P and K) supply from the compost toward plant uptake. Working with the farm cooperator, the fertilization program will be developed for the on-farm tabletop strawberry production systems.
In terms of identifying appropriate strawberry cultivars, we are proposing to evaluate four strawberry cultivars in this compost-based tabletop production system in caterpillar tunnels. One is ‘Pearl,’ a white strawberry cultivar, which attracts interest from Florida growers due to its unique whiteish color and pineapple aroma. Mike Garcia, the owner of Everoak Farm is very excited to test this cultivar. Another strawberry cultivar we are proposing is ‘Florida Radiance’, which has been reported to perform very well in protected culture and hydroponic systems in Europe as it has pollinated well. ‘Florida Radiance’ is likely to also perform well under caterpillar tunnel systems. Another cultivar we would like to test is ‘Florida Brilliance’, which is a leading cultivar currently used by Florida strawberry growers. It is not as well-tested in protected culture systems as ‘Florida Radiance’, but as it is currently the leading variety in the Florida industry, and further evaluation in alternative strawberry production systems is warranted. Another cultivar we are proposing to evaluate is the newest released ‘Medallion’. It has been reported to perform well for open field strawberry production in Florida and deserves to be tested in the tabletop system. All four cultivars will be grown in the three types of compost substrate treatments in the tabletop production system under caterpillar tunnels.
By helping the grower build the compost-based tabletop strawberry production system in the low-cost caterpillar tunnel onsite in a cost-effective way, we expect to establish a partnership with local growers for technology transfer which allows for a practical assessment of tabletop strawberry cultivation system with respect to its potential for improving long-term sustainability of local strawberry production.
Project objectives from proposal:
The objectives of this study are to: 1) determine and evaluate three different types of compost-based growth substrates that are locally available for tabletop strawberry production; 2) evaluate the performance of four strawberry cultivars including ‘Pearl’, ‘Florida Radiance’, ‘Florida Brilliance’, and ‘Medallion’ grown in compost-based tabletop systems in caterpillar tunnels; 3) assess fruit yield and quality as affected by different growth substrates and cultivars; and 4) analyze the costs and returns of establishing tabletop strawberry production to determine its economic feasibility.
This on-farm research project will be conducted at the Everoak Farm located in Orlando, FL. Development of this project is largely driven by grower’s interest and their active participation in brainstorming and collaboration. Mike Garcia at Everoak Farm suggested to test their on-farm compost for this research project, as they have a desire to recycle their on-farm crop residue and waste and to minimize expenses associated with sourcing external substrates for growing strawberries. Other types of composts will be provided by local composting facilities in Florida.
Dr. Zhao will work with our farm cooperator to successfully install the tabletop hydroponic strawberry production system under their caterpillar tunnels. After the strawberry plants are established, our farm cooperator will actively manage strawberry plants in terms of daily irrigation, fertilization, pest and disease control, etc. under Dr. Zhao’s guidance. Dr. Zhao will help develop the fertilization program based on the on-farm conditions and management practices.
Experimental design of tabletop strawberry study: There will be 12 combinations of treatments consisting of four strawberry cultivars and three compost-based substrate treatments. Strawberry plants will be transplanted in the tabletop production system under caterpillar tunnels during September or October 2023 and 2024. The experiment will be arranged in a randomized complete block design with 4 replications. Each experimental unit will consist of 16 strawberry plants grown in a staggered pattern in each trough.
Compost testing: To determine and evaluate the feasibility of three types of composts as growth media for strawberry production, compost testing will be performed. Physical and chemical properties of the composts including BD, TP, WHC, pH, EC, OM, total C, N and other essential nutrients such as K, Mg, Fe, Mn and Ca will be analyzed before designing the tabletop strawberry system. Available nutrient contents (NH4-N, NO3-N, P and K) will be determined throughout the growing season at: 1) transplanting; 2) first harvest; 3) mid-season; and 4) final harvest. Fertilizer supply will be adjusted based on the nutrient supply provided by the composts.
Plant tissue analysis: To evaluate the performance of strawberry plants, representative strawberry plants will be sampled in each experimental unit at early, mid and final harvest for measuring biomass accumulation, crown number, and plant macro- and micronutrient uptake.
Disease resistance assessment: Disease assessment is another aspect we would consider in terms of evaluating the performance of strawberry cultivars grown in different types of compost-based growing media. Both disease incidence and severity will be assessed as appropriate. Plant samples will be sent to the University of Florida Plant Diagnostic Center for disease identification and confirmation. A 0-5 rating scale (0 = no symptoms and 5 = plants dead) will be used to evaluate the disease severity. Procedures for monitoring and assessing other diseases will be developed as the experiment progresses and symptoms are observed. Assessment of pest pressure will also be conducted as problems emerge.
Fruit yield and quality: To assess the fruit yield and quality, strawberry fruit will be harvested twice a week with marketable fruit number and weight yield recorded. Fruit quality attributes such as soluble solids content (SSC) and titratable acidity (TA) will be measured during early, mid, and late harvest.
Economic analysis: Cost-return analysis will be conducted to evaluate the profitability tabletop hydroponic strawberry production in the caterpillar tunnels. In addition to the estimated transplant costs, other variable and fixed costs of crop production will be estimated for a partial budget analysis. The revenue per unit production area will be calculated as revenue = yield × price, and the profit will be calculated as profit = revenue – (variable cost + fixed cost). Additionally, a sensitivity analysis will be performed to capture the variation of net returns as influenced by market price of strawberry fruit, fruit size, and harvest period in order to offer growers a more comprehensive assessment of economic feasibility.
Data analysis: Data will be transformed if necessary to ensure adherence to the assumptions of linear mixed models. Analysis of variance will be performed using the MIXED procedure of SAS. Multiple comparisons between treatments will be conducted using Tukey’s test at the 5% level of significance.