Progress 05/01/23 to 04/30/24
Outputs
Target Audience:The target audiences include urban farmers with strawberry operations and those interested in growing strawberries and using soilless culture systems, organic and transitional organic strawberry growers, producers who are looking into alternative growing systems to overcome crop management issues and improve resource use efficiency in strawberry production and for other high-value specialty crops, small and local growers interested in new methods of growing vegetable crops and strawberries, greenhouse and high tunnel growers, researchers and educators, Extension personnel, service providers, agricultural consultants, composting facilities, industry representatives, master gardeners, and undergraduate and graduate students. Changes/Problems:We encountered a delay in setting up our research trials as the installation of caterpillar tunnels and tabletop structures took much longer than expected. As a result, the first harvest was rather late, and the total strawberry yield was lower compared with a typical season. Despite the challenges, this pilot study provided great opportunities for us to gain first-hand information on exploring substrate options using locally available pine bark and composts, as well as water and nutrient management programs and disease and pest control for tabletop strawberry production. What opportunities for training and professional development has the project provided?Two Ph.D. students joined the project team for their dissertation projects, and several undergraduate students assisted with various research trial activities. Students have been trained and/or gained experience in interdisciplinary research, soilless culture, environmental instrumentation, field experimental design, research data collection, enterprise budget development, and economic analysis. How have the results been disseminated to communities of interest?The USDA-NIFA delegation visiting the University of Florida toured our tabletop organic strawberry production research trials at the Plant Science Research and Education Unit in Citra on January 17, 2024. We also discussed the progress of this project at the integrated organic vegetable production systems field day in Citra in January 2024, which attracted nearly 30 attendees, including urban farmers and local growers, researchers, students, educators, industry representatives, and Extension agents. What do you plan to do during the next reporting period to accomplish the goals?We plan to work with strawberry breeders at the University of Florida and UC Davis to assess a wide range of cultivars for tabletop strawberry production during the next reporting period. Building upon the pilot study on substrate assessment, we will continue to examine the pine bark + compost mixtures with locally sourced materials, together with the application of microbial biostimulants. Partial budget analysis will be used to compare the gain or loss across different cultivar and substrate combinations. Sensitivity analysis will be conducted to determine the impact of strawberry fruit price and substrate and strawberry transplant costs on the net income of tabletop organic strawberry operations in different scenarios. In addition, we plan to conduct the consumer sensory experiment to evaluate the strawberry fruit appearance and flavor attributes and the overall liking of selected strawberry cultivars grown in compost-based substrates. A national online survey will be developed to examine consumers' preferences for fresh produce from urban farms. The survey will estimate consumer willingness-to-pay for strawberries grown in tabletop systems at urban farms. We plan to present research findings at professional conferences and disseminate project results at field days and workshops.
Impacts
What was accomplished under these goals?
Objective 1: Examine major types of composts and other recycled organic waste products for their suitability as growing media in protected tabletop hydroponic strawberry systems. We completed the installation of four caterpillar tunnels (30.48 m × 4.27 m) and the plastic trough-based tabletop structure inside each tunnel on certified organic land at the University of Florida Plant Science Research and Education Unit (Citra, FL) in early December 2023. Three 30 m-long tabletop rows at a height of 1 m were set up in each high tunnel (replication) at a row spacing of 1.07 m, with 30 troughs (1 m × 0.15 m) in each row. All troughs were filled with substrates and covered by white plastic mulch. We focused on examining the mixtures of pine bark and composts as strawberry growing media in comparison with the coco coir control. The four substrate treatments included: 1) pine bark + yard waste-based compost (70:30, v:v); 2). pine bark + yard waste compost (70:30, v:v) with humic substances added; 3). T3: pine bark + bagasse-based compost (70:30, v:v); and 4). pine bark + cow manure-based vermicompost (75:25, v:v). Organic fertilizer (Nature Safe 10-2-8) was also added to each substrate,including the coco coir, prior to strawberry planting. In-season fertigation with liquid fertilizers approved for organic production was applied each day, with application rate and frequency adjusted according to crop stage and nutrient demand. Strawberry planting took place on December 23 and 24, and fruit harvests started in February 2024 and continued through late June. At the end of the growing season, coco coir and the substrate containing vermicompost had the lowest levels of pH and EC. Objective 2: Evaluate strawberry genotypic adaptation to compost-based tabletop hydroponic systems. 'Albion' (day neutral; bare-root plants) and Sweet Sensation 'Florida127' (short day; containerized transplants) were the two strawberry cultivars assessed in this pilot study, focusing on plant growth and health and fruit yield. The first harvest occurred on February 14 and 26, 2024 for 'Florida127' and 'Albion', respectively, with the last harvest on June 27 for both cultivars. Overall, the whole-season marketable and total fruit yields were higher in 'Florida127' vs. 'Albion', although 'Florida127' exhibited a greater incidence and severity of Phytophthora crown and root rot. Moreover, the marketable fruit yield of 'Florida127' did not vary with substrate treatments, whereas 'Albion' showed significantly higher marketable fruit yields in the substrate containing yard waste compost and humic substances and the substrate containing vermicompost, in contrast to the coco coir and the substrate with bagasse compost, primarily driven by the increase in marketable fruit number. The total yield and fruit number of 'Albion' were also significantly higher in the substrate containing vermicompost relative to other substrates, except for the substrate containing yard waste compost and humic substances. No significant difference among substrates was observed for the total yield of 'Florida127'. Objective 3: Determine the effectiveness of applying arbuscular mycorrhizal fungi (AMF) for enhancing production efficiency of tabletop strawberry systems. Trichoderma (RootShield PLUS Granules) and AMF (MycoApply Endo) products, including the control with no microbial biostimulant, were also incorporated into the four substrate treatments and the coco coir control to assess their potential benefits. Interestingly, no significant responses were found in 'Albion' in terms of fruit yield components, whereas some trending effects were observed in 'Florida127'. Nevertheless, no evident impact of Trichoderma and AMF on tabletop strawberry yield performance was found in this pilot study with a late planting date. Objective 4: Identify economically feasible compost-based hydroponic systems and market opportunities for urban farms. We constructed data sheets for conducting cost-benefit analyses using data collected from the substrate and microbial biostimulant trials with the two strawberry cultivars. The total cost of substrate-based tabletop strawberry production in caterpillar tunnels was divided into four major components: preplant, production, harvesting, and fixed costs. In the preplant cost category, we calculated the costs of different substrates (e.g., coco coir and pine bark + compost substrates) together with the application of Trichoderma and AMF products, strawberry transplants, and labor for transplanting. In the production cost category, we calculated the cost of organic fertilizers, irrigation water, disease and pest control measures, and labor for crop management. The harvesting cost primarily consisted of labor. The fixed costs included material and installation costs of the caterpillar tunnels and the tabletop systemas well as the irrigation and fertigation system. The lifespan of the caterpillar tunnel and the base structure of the tabletop system were estimated at ten years, with troughs of the tabletop system estimated at four years. We estimated the total revenue of tabletop organic strawberry production using the strawberry retail price from the USDA-AMS, with different shipping points, for the period from February 1 to June 30, 2024. The organic strawberry prices with the shipping point of Central Florida were used, while the prices from California were applied when the prices were unavailable for Florida. Due to the significant fluctuations in strawberry yield performance and market price during the harvest season, our calculation used weekly average prices and yields instead of average values throughout the entire harvest period. The estimated costs and gross returns of tabletop strawberry production were then used to calculate and compare net returns for different strawberry cultivars and substrate treatments. Objective 5: Develop integrated Extension programs and assessment approaches to improve project performance and outcomes for advancing sustainable urban production systems. We introduced this tabletop strawberry production project at the integrated organic vegetable production systems field day in Citra, FL on January 23, 2024. In addition to a 15-minute interactive presentation, we also showed the participants our ongoing research trials during the research field tour. The feedback we received is highly positive, and the Q&A session offered insights into organizing a field day dedicated to this project in Spring 2025. Objective 6: Establish experiential-learning opportunities for engaging students in urban agriculture research and outreach. The high tunnel tabletop organic strawberry production demonstration trials comparing coco coir and pine bark + compost substrates and different cultivars were set up at the Horticultural Sciences Department Teaching Farm on the University of Florida campus in Gainesville. The trough-based tabletop strawberry system has been used as an effective teaching tool to discuss the development of innovative growing systems and technologies for promoting water conservation and nutrient cycling,and the use of soilless culture for organic production. Students in the organic and sustainable crop production courses were engaged in managing the tabletop strawberry demonstration trials. Undergraduate student interns were also trained to help with data collection during the production season.
Publications
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