Final report for LS19-315
Project Information
Seeds represent the fundamental basis of agricultural productivity and secure food systems. Farmers depend on an array of seed producers to provide the planting materials necessary for meeting the food, fuel, fiber, natural resource conservation and plant-based aesthetics demands of the United States. However, seed production in the U.S. occurs predominantly outside of the Southeastern region. Seed availability is often limited to protected varieties displaying broad adaptability and national or global acceptance. These varieties often require substantial inputs to maintain long-term productivity. Alternatively, a sustainable agricultural system seeks to provide affordable, high-quality, regionally appropriate seeds from diverse crops.
The Southeastern region lacks significant seed production, seed research, and varietal improvement when compared to other regions of the country. Yet significant demand exists in the Southeastern region for increased seed production of regionally adapted varieties and research leading to improved seed production practices. Here, we propose a systems-based research project informed and participated in by Southeastern farmers.
The project addresses principal barriers to entry into seed production markets: 1. Producing and maintaining high quality seeds in hot, humid environments and 2. Decision-making factors that determine whether farmers are likely to adopt novel yet established practices and technologies. Our robust outreach component consisting of farmer managed on-farm trials and field days, networking at farmer-based conferences, and accessible online learning tools will share results and practices throughout the Southeastern region.
We expect our project will enhance Southeastern farmer seed systems by: Enabling small and medium sized farmers to control and improve seed production and storage, identify potential barriers that limit adoption of new seed production technology and practices, improving potential profitability through seed production, educating limited resource farmers throughout the region on new seed production methods, and contributing the ongoing efforts to establish a Southeastern seed network.
Our project can increase sustainability in several ways. First, farmers with knowledge of new seed production practices can apply this to many emerging crop varieties thereby promoting crop diversification. In fact, the most fundamental ability to produce high quality seeds in the Southeast opens itself to a broad range of possibilities for plant breeding, varietal trials, expanded production, and exploration of unique markets and potentially profitable crop, forage, and edible culinary seeds. Second, we promote farmer success by exposing them to prove technologies that maintain high seed quality throughout the seed production chain. Third, by incorporating farmer managed on-farm trials we provide site specific information related to stand establishment and seedling vigor of previously treated seeds. This type of trial structure considers real world variability in production systems, which is of paramount importance given the hot, humid conditions and excessively drained, nutrient-poor, sandy soils of the Southeastern coastal plain. Fourth, farmers can expand use of regionally adapted varieties and, in turn, reduce the need for intensive inputs. Finally, farmers can apply new methods that reduce post-harvest seed losses to a variety of crops in their systems.
Our main objective is to examine the feasibility of applying scalable, cost-conscious seed production technologies that maintain high seed quality.
- Assess relationships between fruit/seed phenology and physiological aspects of seed development to identify harvest timing thresholds for maintenance of seed quality.
- Compare dessicant-based drying technologies that maintain quality of crop seeds produced in warm, humid environments.
- Develop a socio-ecological model of farmer decision-making that accounts for the roles of economic factors, farmer expertise, known and unknown risks, and potential benefits.
- Perform quantitative economic and risk analyses that examine the economic feasibility of new production methods for selected crop seeds.
Cooperators
- - Producer (Educator and Researcher)
- - Producer (Educator and Researcher)
- - Producer (Educator and Researcher)
- - Producer (Educator and Researcher)
Research
Our farmer partners suggested three annual crops (Brassica rapa L. ‘Yukina Savoy’ [Brassicaceae], Cucurbita moschata ‘Bellevue Butternut’ [Cucurbitaceae], and Vigna unguiculata ‘Purple Hull’ [Fabaceae]) and one perennial wildflower Milkweed (Asclepias tuberosa L.) for planting. Annual crops were planted in three farms located in Gainesville (Siembra Farm, The Family Garden, and University of Florida Field & Fork Farm) and the perennial crop was grown at Wildflowers of Florida in Alachua. Farmers participated actively in the project. Soil samples from each farm were sent to UF/IFAS Analytical Services Laboratories in Gainesville, for test on amount of Ca, Cu, Fe, K, Mg, Mn, P, N, Zn, and organic matter, and provided to farmers to make their own decisions based on results. Farmers performed agricultural practices such as soil preparation, irrigation, fertilization, plant disease and insect prevention, and harvesting based on their own criteria.
Objective 1: Assess relationships between fruit/seed phenology and physiological aspects of seed development to identify harvest timing thresholds for maintenance of seed quality.
Experiment 1 entailed tracking changes in fruit color, chlorophyll fluorescence of seeds, seed dry matter reserve accumulation, tissue water content; and seed water potential during development to identify markers of harvest maturity from seeds grown at the different farms. We tagged 50 to 200 randomly selected flowers at anthesis from a minimum of 30 plants for each crop and monitored subsequent fruit development. We then compared color changes during maturation for 10 randomly selected fruits against colorimetric standards (Munsell Color Chart for Plant Tissues) to estimate seed harvest maturity. We also randomly harvested a minimum of 10 fruits at a minimum of four time points after anthesis. The time points for harvest coincided with early, middle, and late stages of fruit development and at fruit dehiscence for dry fruits.
We measured changes in seed chlorophyll fluorescence non-destructively with a portable seed chlorophyll meter on a sample of 100 seeds per developmental time point.We used the same samples to measure absorbance and reflectance at different light wavelengths to determine physical characteristics of developing seeds using a multi-spectral machine vision system. Subsequently, we submitted developing seeds to standard germination tests in the lab. We also measured seed water potential using a dewpoint potentiometer and changes in seed fresh mass, dry mass, and water content on a dry mass basis throughout development on separate seed samples.
Experiment 2 involved controlled deterioration studies relating harvest maturity to important physiological seed quality parameters including germination/seedling emergence percentage, germination rate and seedling vigor. We exposed seeds to conditions of high temperature (45 °C) and humidity (65%) for up to 150 days. We removed seeds from experimental conditions at predetermined intervals then measured germination in the lab at 25 °C.
Objective 2: Compare desiccant-based drying technologies that maintain quality of crop seeds produced in warm, humid environments.
Experiment 1 consisted of examining seed deterioration in non-climate-controlled storage. We stored seeds from selected crops in closed paper bags within a barn. We monitored relative humidity and temperature at seed level with data loggers. We then collected random lots of 100 seeds after 1, 3, 6, 9, 12, 15, 18, 21 and 24 months then subjected these to standard germination tests at 25°C to assess viability loss over time.
Experiment 2 used lab-based germination tests to compare the efficacy of different desiccant based drying systems and maintenance of seed viability under dry conditions. Treatments consisted of two types of desiccants (silica gel or zeolite drying beads); two storage equilibrium relative humidity values (35 and 15% RH); two storage temperatures (25 and 5°C); and up to three storage durations.
Experiment 3 made use of the same treatments described above but incorporated field establishment rather than lab-based germination tests. Seed harvest and planting times vary for spring seed crops (i.e. brassicas) and summer seed crops (i.e. cowpea, cucurbits, milkweed). Therefore, we adjusted storage times for these crops.
Experiment 4 assessed the field establishment of Yukina Savoy plants grown from seeds raised at local farms compared to seeds from an initial lot grown in Italy. Seeds from the initial lot were tested for germination upon receipt and samples were distributed to partner farmers. The remaining seeds were stored in a refrigerator until the next growing season. Farmers cultivated Yukina Savoy plants from the provided seeds according to their farm management plans and allowed plants to go to seed. Mature seeds were harvested from each farm. Seeds from the initial lot and those grown on local farms were then tested for germination. Seed samples from each lot were then propagated in a greenhouse and transplants were grown within an on-campus farm plot. Yukina Savoy plants were harvested after 28 days. Biomass and plant quality data were compared across the different seed sources.
Objective 3: Develop a socio-ecological model of farmer decision-making that accounts for the roles of economic factors, farmer expertise, known and unknown risks, and potential benefits.
Sampling and Data Collection. This study employed a purposive sampling strategy to recruit both current seed producers and non-seed producers (i.e., growers not currently engaged in seed production but who expressed interest in this practice) (Braun & Clarke, 2006). The call for research participants was posted and shared with organizations in the Southeastern US, including the UF/IFAS Center for Sustainable and Organic Food Systems, Florida Farm Bureau, National Women in Agriculture Association-Florida Chapter, Citrus Grower Association Florida, Florida Black Farmers and Agriculturalists Association, Florida Organic Farmers, Farmworker Association of Florida chapters, and Organic Seed Alliance. Data were collected via semi-structured Participants consented to record interviews, which were subsequently anonymized and transcribed. Interviews were stored on a password-protected (encrypted) computer. The estimated total time for each interview ranged between 30 and 40 minutes. This study was approved by the UF Institutional Review Board (IRB study # 201802239). Participants provided written informed consent. Participants were free to withdraw from the study at any time. Each participant received a compensation of $50 for the time and expertise.
Sample and participants. The sample for this study included twenty-one growers with farms located in Florida, Georgia, South Carolina, North Carolina, Virginia, and West Virginia. 11 of the growers indicated being seed producers, and 11 were non-seed producers. All participants were 18 years of age. The majority of farmers in our sample (68.18%) indicated having farms of less than five acres. The sample was comprised of ten female farmers and twelve male farmers. Over three-fourths of the participants had a college degree or higher educational attainment.
Data analysis. This study employed thematic analysis to investigate the drivers and barriers faced by growers in the seed production industry and those who wish to enter this market. Specially, we employed a two-step approach to analyze interview transcripts (Braun and Clarke, 2006). Each interview was professionally transcribed and reviewed by an experienced qualitative researcher for accuracy. First, we engaged in the open coding phase to identify salient themes. Two members of the team completed this step. Each researcher independently reviewed interview transcripts and applied conceptual-level codes developed during the open coding phase. In the second step, researchers met to compare coding and salient themes. Discrepancies in coding and the selection of themes were discussed to ensure inter-coder reliability. Data were analyzed using a grounded theory approach to identify themes (Clarke, Braun & Hayfield, 2015).
References
- Braun, V., and Clarke, V. (2006). Using thematic analysis in psychology. Qual. Res. Psychol. 3, 77–101. doi: 10.1191/1478088706qp063oa
- Clarke, V., Braun, V., & Hayfield, N. (2015). Thematic analysis. Qualitative psychology: A practical guide to research methods, 222(2015), 248.
Objective 4: Perform quantitative economic and risk analyses that examine the economic feasibility of new production methods for selected crop seeds.
In this study, we employed enterprise budges to project costs and returns for growing selected crops (i.e., Yukina Savoy). Each budget indicates a system of production and includes costs and returns associated with an acre basis (Kay, 1994; Tweeten, 2019). In year 2 of the project, participating farmers on-farm trials collected data every week for a number of inputs, including labor, fuel, repair, and maintenance. Inputs were classified as preharvest variable or operating costs, harvesting and marketing costs, variable costs, and fixed costs. To collect data, we used and adapted an existing seed production budget created by a budget tool developed by Organic Seed Alliance (https://seedalliance.org/publications/seed-economics-toolkit/). To ensure the appropriateness of this tool for data collection purposes, members of the PEP and participating farmers evaluated the data collection tool for content, quality, and utility. Based on the cognitive testing results, we modified and calibrated the tool. To complement the data collected from on-farm trials during the 2021-2022 season, we used to cost, yield, and other input data from sources available from governmental agencies (e.g., USDA, U.S. Department of Labor) and the academic literature. This study was approved by the UF Institutional Review Board (IRB study # 201802239). Participants provided written informed consent. Participants were free to withdraw from the study at any time.
Kay, R.D. & Edwards W.M. (1994). Farm management. McGraw-Hill.
Tweeten, L. (2019). Agricultural policy analysis tools for economic development. Routledge.
Objective 1: Assess relationships between fruit/seed phenology and physiological aspects of seed development to identify harvest timing thresholds for maintenance of seed quality.
Fruits and seeds of all selected vegetable crops displayed typical developmental patterns associated with species producing desiccation tolerant seeds regardless of different crop management practices at each farm and harvest years. Seeds of Yukina Savoy, Bellevue Butternut, and Cowpea reach harvest maturity between about 35 to 50 days after anthesis according to decreasing chlorophyll fluorescence and seed-water relations (e.g. seed water potential range -100 to -120 MPa). Germination ability increased throughout development. Fully mature seeds displayed rapid (2-7 days) and complete germination (> 98%) thus supporting the production of high quality seeds across local farms. We found that Yukina Savoy seed production occurs best when starting plants in the late fall rather than early spring. Likewise, early fall rather than summer represents appropriate time to start cowpea for seed production. Bellevue Butternut plants produce high quality seeds during the summer.
We could not collect a sufficient amount of butterfly milkweed seeds to conduct developmental studies. Nonetheless, mature seeds germinated readily and we did not encounter seed dormancy mechanisms that inhibited germination or required additional treatments to promote germination. Therefore, we adapted our methods, in collaboration with our farmer partner, to focus on seed production strategies. Growing adult butterfly milkweed plants in a weed block fabric system did to decrease the amount of seeds produced compared controls (ca. 1325 per plot). However, shading reduced seed production from 1.2 to 9.6-fold depending in duration of shade exposure. Seed quality was also highest for seeds collected in July and decreased progressively through September when these perennial plants started to go dormant.
Objective 2: Compare desiccant-based drying technologies that maintain quality of crop seeds produced in warm, humid environments.
Viability of Yukina Savoy, Bellevue Butternut and cowpea seeds decreased precipitously between 9 and 12 months of storage in a non-climate controlled barn, suggesting that methods to control seed moisture content fluctuations are necessary to maintain high seed viability. We found no difference in lab-based germination ability (> 95%) of Yukina Savoy, Bellevue Butternut, or cowpea seeds dried with silica gel or zeolite beads then stored at 25 or 5 °C for 9 months. Field-based seedling establishment studies are on-going.
Yukina Savoy plants grown from seeds produced in Florida consistently outperformed plants grown from seeds produced in Italy in terms of vegetative and root biomass production and overall plant vigor. For example, seedlings from Florida grown seeds were about 1.26-fold longer than seeds from the international source. Likewise, plant from local seeds were 8-12% taller and 21-25% wider than plants from the international source. Plants derived from the international source displayed a 46-55% reduction in leaf fresh and dry mass and a 46 to 66% reduction in root dry mass compared to plants from local seeds. The proportion of plants grown from local seeds that displayed high vigor index values (i.e. ≥ 4) was always greater than the vigor index value (i.e., 3) for plants grown from international seeds.
Objective 3: Develop a socio-ecological model of farmer decision-making that accounts for the roles of economic factors, farmer expertise, known and unknown risks, and potential benefits.
The analysis produced six themes. The first salient theme related to the likelihood of engaging in seed production in the future. Overall, participants appraised a positive outlook on their ability to produce seeds. However, the time proximity, likelihood of behavior, and purpose varied between seed producers and non-seed producers. For example, seed producers were more confident in the ability to continue growing seeds within the following 12 months and the next five years. Importantly, seed producers indicated growing seeds for commercial purposes, personal use, or exchange with other farmers. On the other hand, non-seed producers expressed the intention and willingness to engage in seed production practices within the next five years but not in the next 12 months. In addition, non-seed producers planned to engage in seed production for personal use only. A second elicited theme dealt with perceived barriers faced by growers engaged or interested in seed production. Seed producers indicated a number of barriers that hindered the sustainability of their seed production practices, including financial resources to expand their operations, access to credit lines or financing options, and proper infrastructure to manage seed storage. Non-seed producers also perceived several barriers: lack of technical expertise and knowledge, lack of financial resources, lack of access to credit or financing options, lack of knowledge in ways to market and sell seed, and inadequate infrastructure to grow seeds for commercial purposes. A common barrier to both groups was the limited information on crops to grow for seed production purposes. Participants indicated that the lack of economic data and crop yield in the Southeastern United States limited their ability to engage effectively or willingness to engage in seed production. Another theme identified was the positive factors associated with seed production, including experience engaging in seed production, knowledge on how to manage seed storage, and market and sell seeds. These predictive factors were strong for current seed producers only. A four-theme was related to crops of interest for seed production. While most farmers highlighted the importance of crop diversity and the need for more experimental trials with crops in the Southeast, there were three crops that the majority agreed were key crops of interest: tomatoes, squash, and culinary herb crops. A salient subtheme was the importance of selecting crops produced for their commercial value. The notions of yield and profitability were the underlying drivers of this subtheme. A fifth theme related to the benefits and importance of seed production in agriculture, particularly in the Southeast. Participants described benefits in terms of positive environmental effects (e.g., crop diversity, high-quality seeds with high seed mass, high seed longevity), social impact (e.g., food security and national interest in the context of shocks like pandemics and disasters), and economic benefits (e.g., resilient, and competitive seed supply chains and business diversification). The last theme elicited from the interviews related to the interest and support for regional, collaborative seed systems. The exploration of different schemes and structures for seed-producing cooperatives was a salient result.
Objective 4: Perform quantitative economic analyses that examine the economic feasibility of new production methods for selected crop seeds.
Members of the PEP reviewed and validated input data utilized for analysis. Delphi Method, a process to achieve convergence of opinion on a specific question, was employed to validate the degree of accuracy of cost and revenue estimates drawn from literature and market surveys (Linstone & Turoff, 2002; Okoli & Pawlowski, 2004). Our goal was to ensure the use of sound and reasonable cost and revenue estimates that reflect the current market situation.
Land and Fixed Expenses (Yukina Savoy case)
|
Unit |
Annual Cost |
Cost per Acre |
|
Land-Mortgage |
$6,265 |
$313.25 |
|
Property Taxes |
$897 |
$44.85 |
|
Tangible Taxes |
$1,264 |
$63.20 |
|
Liability Insurance |
$1,740 |
$87.00 |
|
Building/Utility Maintenance |
$3,948 |
$197.40 |
|
Office Supplies |
$780 |
$39 |
|
Org. Cert/Prof Fees |
$3,870 |
$193.50 |
|
Lawn Care |
$2,065 |
$103.25 |
|
Cover Crop (+tractor) |
$3,555 |
$177.75 |
|
Total |
$24,384 |
$1,219.20 |
|
Crop: Yukina Savoy |
Input |
|
Plastic or Dirt |
3982 |
|
Seed $ |
235 |
|
Transplants (0.06) |
0 |
|
Labor (0.05) |
0 |
|
Extras (thinning, ex fert.) |
0 |
|
Yeild |
7000lb |
|
Harvest Hrs (19) |
(12)$228 |
|
Packing (19) |
(12)$228 |
|
Packaging |
5950 |
|
Total/Ac |
10623 |
|
Total/bed (600 ft) |
885 |
|
Total/bunch//lb |
1.52 |
Linstone, H.A. and Turoff, M. 2002. The Delphi method. Techniques and applications. Vol. 18. Addison Wesley Publishing.
Okoli, C. and Pawlowski, S.D. 2004. The Delphi Method as a research tool: An example, design considerations and applications. Information & Management 42:15-29.
Educational & Outreach Activities
Participation Summary:
- We recruited a diverse panel of eight growers to serve in the Production Expert Panel (PEP) for this project. We recruited these experts based on needed technical expertise and prior experience with production systems and/or extension engagement in seed improvement, saving, and preservation. The PEP governs the project through biannually facilitated meetings and evaluations. The PEP is empowered to make decisions to ensure that the research continues to address critical grower needs and opportunities and to provide us with continuous assessment of our progress toward project goals, with recommendations for making adjustments that may improve performance over the life of the project.
- We held the first PEP meeting on January 20, 2021 (1:00-3:00 p.m.). During this session, experts provided feedback and calibration for the seed production survey.
- The research team co-authored a technical publication Basic Seed Saving describing vital information to consider when deciding to save seeds from vegetable crops. This publication is currently under review and will be published in the UF Electronic Data Information Source (EDIS) portal.
- We held an in-person team gathering/retreat on Wednesday, October 14, 2020. UF approved this in-person activity, and participants followed COVID-19 guidance provided by the Centers for Disease Control and Prevention (CDC). The purpose of the retreat was for the research team to provide an update on activities progress and the project’s next step. Also, we asked farmers to describe lessons learned during the first year of the project.
- We created a webpage that includes the project’s objectives, activities, photos, and team members. Website link:https://floridafoodandag.com/new-home/enhancing-seed-production-of-regionally-adapted-crops). The website is housed on the Center for Sustainable and Organic Food Systems’ main webpage.
- We conducted a field day in the Summer of 2022. This 2-hour event was held at the UF/IFAS Seed Biology Lab (https://hort.ifas.ufl.edu/seed-biology-lab/lab-members/). Participants learned about our research and seed production practices. The event included a tour of the lab, where team members provided an overview of the equipment and tools in the lab and discussed the latest research conducted in the lab. The tour was followed by a discussion workshop, where participants shared their views on recommendations, priorities, and trajectories for future research on seed production.
Learning Outcomes
Project Outcomes
We worked with four small holder, local, farmer collaborators to identify three vegetable and one wildflower crop of interest. We investigated the influence of 1) crop management and seasonal timing on seed development, seed yield, and proportion of filled seeds; 2) seed source (i.e., locally produced vs. international origin) on subsequent crop traits; and 3) post-harvest seed treatments on germination capacity.
We discovered that the production of high-quality vegetable and wildflower seeds is feasible despite Florida’s hot, humid climate. Season of planting is crucial. For example, farmers should plant Yukina Savoy (Brassica rapa L. subsp narinosa) in the late fall to obtain healthy, high-quality seeds by mid-spring. Planting Yukina Savoy in the late winter/early spring pushes the seed production window into late spring. However, disease pressure increases considerably at this time as daily humidity and rainfall potential increases. Similarly, cowpea (Vigna unguiculata) should be planted by mid-September rather than June or July to avoid disease pressure that influences seed quality. Production of Bellevue Butternut (Cucurbita moshata) squash seeds does not seem adversely affected by its typical production season.
We found that seed development of the selected vegetable crops is consistent despite considerably different farming practices and crop management. Moreover, we were able to pinpoint optimal widows throughout the seed developmental program that contribute to maximum germination ability, minimum seed moisture content, and resistance to aging stress. Farmers were often interested in collecting seeds early during the developmental program. Nonetheless, we were able to demonstrate the negative impact of early collection on seed quality. We also determined that locally sourced seeds of Yukina Savoy produced plants with better vigor and greater biomass than plants produced from seeds of international origin after one generation of seed production in Florida.
We determined that butterfly milkweed (Aslcepias tuberosa) seed yield was similar between the first and second years of seed production. This plant has the potential to produce > 200,000 seeds per hectare. Growing butterfly milkweed plants in a landscape fabric system to minimize competition from weeds did not diminish seed yields. But producers should avoid shading as this produces 1.2 to 9.6-fold decrease in seed yield depending on duration of shade exposure. Butterfly milkweed has an extended flowering season and produces fruits from June through September. Our research revealed that seed quality, in terms of germination capacity and rate, was better for seeds harvested in July or August rather than September. We also found that butterfly milkweed seeds from plants originating in north-central Florida do not require cold, dry conditions to promote germination. In fact, this often-cited recommendation was detrimental to germination.
Our conversations with farmer collaborators and a formal survey of the wider farming community revealed that many farmers in the region have the intent to enter seed production but lack resources (e.g., financial, technical, informational) to do so. Some farmers also expressed concerns on post-harvest handling and storage of seeds. This makes sense in Florida’s hot, humid climate that is not conducive for seed storage especially for limited resource farmers who do not possess climate-controlled facilities for maintaining seed viability. Our farmer collaborators also indicated that they plan to continue seed production for butterfly milkweed, Bellevue butternut squash, and cowpea. One collaborator mentioned that while seed production of Yukina Savoy is feasible, they would not continue with this crop as it may not match well with their farm management plan. Nevertheless, the same farmer decided to purchase some of the desiccant based seed drying systems that we demonstrated as part of the project.
Our farmer partners, via outreach activities such as famer field days and producer expert panels, displayed a change in knowledge related to the importance of: seed development on the production of high-quality seeds, planting time to offset disease pressure that may negatively impact seed crops, locally produced seeds to improve crop productivity, and cultivation practices that influence seed yield. In terms of change in actions, one farmer partner adapted their seed production practices as a result of our findings while another adopted new desiccant-based seed drying technologies used in our studies.