IMPROVING SUSTAINABILITY AND PROFITABILITY OF STRAWBERRY PRODUCTION IN VIRGINIA AND MID-ATLANTIC REGION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1014997
• Project Start Date: Jan 1, 2018
• Project End Date: Dec 31, 2022
• Program Code: [(N/A)]- (N/A)

Recipient Organization
VIRGINIA POLYTECHNIC INSTITUTE
(N/A)
BLACKSBURG,VA 24061

Performing Department
Hampton Roads Agri Research & Ext Ctr

Non Technical Summary
Strawberries are one of the major high value crops cultivated in North America with an estimated value of $2.3 and $2.8 billion during the past three years. Annual per capita consumption for strawberries in the U.S. has gone up from 1.97 lbs in 1980 to 7.7 lbs in 2015. In Virginia, producers cultivate about 290 acres of strawberries. The majority of commercial strawberry growers in the mid-Atlantic and southeastern U.S. have transitioned from matted-row production to annual hill plastic mulch production known as strawberry plasticulture. This method generally relies heavily on the use of plastic mulches and preplant fumigants to minimize risk of soil borne diseases and maintain profitable yields. As per the Montreal Protocol Act of 1987, the most effective fumigant combination, methyl bromide (MB) + chloropicrin (Pic), can no longer be used due to phase out of MB as fumigant in 2005, for developed countries which includes the U.S. Since the ban of MB, alternatives to MB + Pic are being utilized, but crop yield and quality have been reduced, and there are concerns about negative effects of the alternative fumigants on the health of farm workers and neighboring residents. Loss of MB also creates opportunities to investigate other tools that can be used to maintain economic viability and profitability of berry farms. These includeevaluating newer non-fumigant treatments such as Anaerboic soil disinfestation for treatment efficacy and economics,newer cultivars for higher yielding potential and fruit quality, season extension tools to capture a higher price for early market produce, and using supplementary nutrients to boost yield and fruit quality.

Animal Health Component

90%

Research Effort Categories

Basic

0%

Applied

90%

Developmental

10%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
202	1122	1080	50%
213	1122	1140	25%
212	1122	1160	15%
102	1122	1010	10%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 102 - Soil, Plant, Water, Nutrient Relationships; 202 - Plant Genetic Resources; 213 - Weeds Affecting Plants;

Subject Of Investigation
1122 - Strawberry;

Field Of Science
1160 - Pathology; 1010 - Nutrition and metabolism; 1080 - Genetics; 1140 - Weed science;

Keywords

local carbon source

anaerobic soil disinfestation

season extension

cultivar

fertility

Goals / Objectives
The overall goal of the project is to investigate tools and strategies that can be used to maintain economic viability and profitability of strawberry farms after the loss ofmethyl bromide.These toolsinclude evaluating non-fumigation strategies new to the region, newer cultivars for higher yielding potential and fruit quality, season extension tools to capture a higher price for early market produce, andevaluating supplementary nutrients to boost yield and fruit quality.Objectives.Objective 1. To evaluateanaerobic soil disinfestation (ASD)treatments for annual strawberry production under Virginia climactic conditions. Experiments within this objective will:1.1 compare locally available C sources for their effects of ASD on soil-borne weeds inoculated at two soil depths using a two-way ANOVA.1.2. determine impact of ASD treatments on strawberry crop yield and understand their effects on weed density and disease occurrence in the field.1.3. weigh the economic feasibility of including ASD treatments as alternatives to fumigation.Objective 2. To evaluate strawberry cultivars and advanced genotypes at various geographic locations in open-field environment in Virginia utilizing a randomized complete block design at each location.Objective 3. To understand in a randomized block design, the feasibility of strawberry production in high tunnel environment. Specific objectives will determine: 3.1. evaluating cultivars suitable for high tunnel environment by measuring crop yield, fruit firmness, fruit size, total soluble solids, and antioxidant capacity. 3.2. economic feasibility of strawberry production in high-tunnel environment.Objective 4. to determine using a one-way ANOVA, if root-coated and foliar applied nutrient applications have a role in strawberry production to improve berry yield and fruit quality including fruit firmness, size, total soluble solids, and antioxidant capacity.Objective 5. To extend findings of the research to commercial berry growers via presentations, hosting field days, newsletters, grower meetings, and publications.

Project Methods
Objective 1. ASD treatment for strawberry production. In the first year, we will evaluate potential C sources to be used for ASD for their efficacy on weed seeds in greenhouse or growth chamber pot studies filled with field soil. Potential C sources include mustard seed meal, grape pomace, residues of summer-seeded cover crops including buckwheat and pearl millet, and probiotics such as yeast. In a replicated, randomized design, we will saturate the containers with water for the duration of the ASD treatment (typically 3 to 6 weeks) and inoculate them with weed propagules of weed speciesthat are common in strawberry cultivation. We will cover the surface of the ASD treated pots with an impermeable plastic tarp layer at treatment duration to generate anaerobic conditions. Weed bags will be retrieved post treatment and weed seeds will be subject to tetrazolium viability assaytest. Pot studies will be repeated twice or thrice over time depending on variability among replications. Field studies will be conducted in a randomized block design replicated four times in the second and third years. The most promising C sources and dosage from the greenhouse studies will be incorporated via rototilling in raised beds, covered with impermeable plastic tarp and soil will be saturated with drip. These ASD treatments will be compared to standard fumigant treatment and nontreated control.Objective 2. Strawberry cultivars and advanced germplasm evaluation in open-field. We will evaluate advanced genotypes and new cultivars at three to four grower sites in different locations and elevations across the state. These new cultivars would be compared with standard cultivars 'Chandler', 'Camarosa', and 'Sweet Charlie'. We will establish the experimental sites in a randomized complete block design replicated four times at each participating grower locations, and maintain those sites as per grower standard cultural practices. Each location will have 10 to 12 cultivars including advanced germplasm, and each replicate will have 12 plants arranged in two rows to cover 2.1 m linear bed. Strawberry plugs of all cultivars will be ordered from the same nursery source preferably, and planted from the second week in September to the first week in October, depending on geographic location. Plants will be spaced maintained as per grower preferences.Objective 3. Strawberry cultivar evaluations in high tunnel environment. We will evaluate about a dozen cultivars including advanced genotypes in two environments- high tunnel and open field, in a randomized complete block design replicated 4 times with 10 plants per replicate at the Hampton Roads AREC. We will maintain experimental sites as per standard practices based on North Carolina Strawberry Assn. Strawberry Plasticulture Notebook. We will compare promising cultivars with 'Albion' a standard day-neutral cultivar, of choice in high-tunnel production. Strawberry plugs of all cultivars will be ordered from the same nursery source preferably, and planted in the last week of September at 36 cm between plants, in raised beds. We will place temperature probes at strawberry plant canopy levels and at 5 cm depth under soil (root zone) in each bed row under both environments. We will calculate input costs associated with both production systems and anticipated sales receipt based on crop yield will be noted. Budgets will be created to determine economic feasibility of high tunnel.Objective 4. Supplementary foliar nutrient applications. Treatmentswill include a (i) nontreated control, (ii) root-coated nutrient application (0-0-0 with various secondary macro and micronutrients composed primarily of calcium, magnesium and sulfur) (iii) root-coated nutrient application (same product as treatment two) followed by foliar nutrient applications (6-4-3) (iv) foliar nutrient applications only (6-4-3) (v) foliar nutrient applications of cold processed sweetener (OMRI certified). The root-coated nutrient application will be made as per label recommendations. We will apply foliar nutrients as per the label recommendation at 30% bloom, followed by an application once a week during the period of harvesting berries. Rate of each foliar application would be based on label rates. All these nutrient applications will be in addition to the existing recommended strawberry nutrient fertility program followed conventionally by growers in Virginia and included as nontreated control in the study.Data collection and analysis. For objective 1, we will insert temperature probes (U12- 015, Onset Hobo Data Loggers, Onset Computer Corporation, Bourne, MA 02532), pH and ORP sensors (oxidation reduction potential) at 5 and 15 cm depth to record data every 10 minutes during time of treatment in representative pots (for container studies) or plots (in case of field studies) of the different treatments including a nontreated control. We will measure pre- and post-treatment weed seed viability using Tetrazolium tests. Weed seed viability of stock samples will also be determined at time of doing the tetrazolium tests. For objective 1, we will observe weed density by establishing a 1.5 m by 0.8 m wide viewing window on bed tops, soon after transplanting of strawberry plugs. Window will be created by replacing the black tarp with a clear tarp on bed top. We will count the naturally emerged weeds in the viewing window area by species, when weeds compete with crop plant in the window area, but before the weeds became excessively difficult to count. After each evaluation, we will carefully remove the emerged weeds in strawberry beds. We will determine the total weed density for the season and make comparisons of the ASD treatments with nontreated control and a fumigated standard treatment.For all objectives, we will collect strawberry stand count and plant vigor data on a monthly schedule, throughout the growing season, with plant health using a scale of 1=dead plant to 5= extremely healthy. Additionally, any disease incidence will be noted and monitored. Project personnel will harvest field plots two to three times per week, and fruit will be categorized as marketable and non-marketable, in order to calculate yields in these categories by harvest date, and then cumulatively for the entire season. Additionally, we will collect data on fruit size by weighing 25 fruits per plot that will be randomly selected, fruit firmness using a fruit texture analyzer on 5 fruits per plot, and total soluble solids (TSS) using a handheld refractometer on 5 fruits per plot. For objective 4, we will also monitor nutrient content of fruit once every two weeks to see if foliar application changes the nutrient composition.For objective 3, we will monitor air and soil temperature inside and outside the high tunnel using temperature probes. We will analyze data from all studies statistically using SAS v. 9.4 (SAS Institute Inc., Cary, NC, USA). Typical model used will be the analysis of variance (ANOVA) model, with assumptions checked on residuals. Model selection will be based on the multi-way ANOVA model, to see which main, two-way or three-way effects have significant results on dependent variables. Mean separation will be using least significant difference (LSD) at alpha = 0.05.Experimental outcomes from objectives 1,3, and 4 will be translated into estimates of economic impacts to determine feasibility of adoption of the different treatments at commercial grower level. The PI will work with Dr.Bosch,to collect data on economic viability of high-tunnel strawberry production, as well as treatments including promising C sources and foliar nutrient sprays. Crop yield, production costs, and management efforts (variable expenses) will be factored, as well as the fixed cost of the high tunnel will be factored, to calculate the economic feasibility of strawberry production under protected environment.Objective 5. Outreach.Please see the paragraph under Products.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:The target audience included strawberry growers, agriculture and natural resources agents, students, faculty from other institutions,community garden leaders and coordinators, and master gardeners. These stakeholders come from various socio-economic backgrounds and races and are often underserved. Changes/Problems:Due to the pandemic, additional resources were spent to improve protective gear andsafe working conditions for the students and staff. Protocols for social distancing in the laboratory and in the field were put in place. Face-to-face extension programming had to be moved to a virtual format. What opportunities for training and professional development has the project provided?Hands-on training, field, and lab. work experience and data entry skills were provided to anundergraduate student (Objectives 1,2, and 3). Hands-on training, field, and lab. work experience, data entry, writing, and outreach skills were provided to a Ph.D. student(Objectives 1 and 5). How have the results been disseminated to communities of interest?Findings were disseminated at the (i) Southeast Regional Fruit and Vegetable Conference, Savannah, GA (oral), (ii) the Mid-Atlantic Strawberry Education Program, Virginia Beach, VAin February 2020(oral), (iii) videos made at the Hampton Roads Agricultural Research and Extension Center, Virginia Beach, VAin June 2020and shared on social media, (iv) The American Society for Horticultural Science Annual Conference, August2020(oral), (v)preplant strawberry grower meetings held via zoom/Facebook live, (vi) the Virginia Strawberry Association Newsletter in Fall 2019, Winter 2019/20, and Summer 2020(written), vii) Small Fruit News Small Fruit News Posts Southern Region Small Fruit Consortium (smallfruits.org)in Summer 2020. What do you plan to do during the next reporting period to accomplish the goals?Publish two peer-reviewed journal or outreach papers(Objectives 1, 2, and 3). Present findings at the 2021American Society for Horticultural Science Annual Conference, at thestrawberry educational meetings in Virginia, and the Mid-Atlantic Strawberry School. Pursue additional field research under objective one.Work with graduate and undergraduate students, agents, and stakeholders to better understand the impact of this study.

Impacts
What was accomplished under these goals? Objective 1. Our initial greenhouse studies showed that there is potential to reduce dose rates of locally available C sources, such as brewer's spent grain (BSG) in ASD by the addition of yeast to the treatments. Pest efficacy equivalent to a full C dose rate is possible through this combination of reduced rate of C source and distiller's yeast. The two reduced rates of BSG alone were less effective in providing weed control as compared to the full dose rate of BSG, but the two reduced rates of BSG + yeast and the full rate of BSG had significantly better pest efficacy than nontreated control ± yeast treatments. In the open field conditions, neither brewer's spent grain dose rate, nor yeast, had an effect on the total weed density and biomass. However, weed density and biomass in ASD treatments and Pic-Clor 80 (fumigant) were significantly lower than the untreated control. There was no significant difference between brewer's spent grain groups and non-treated control in the 2018/19 growing season on strawberry yield, while all BSG had a higher yield than non-treated control in 2019/20.The findings and methodology from the first set of greenhouse trials have been published in International J. of Fruit Science and the publication is documented in this progress report. Objectives 2 and 3. Our cultivar evaluation and advanced genotype work in the open-field has supplementedthe release of two cultivars by North Carolina State University, described in HortScience journal publication which is documented in this report. Additionally, we have conducted replicated, randomized trial of tenstrawberry cultivars in open-field and high tunnel environments and have presented findings at the 2020 preplant strawberry meeting. Objective 4. Our findings on root-coated and foliar applied nutrient applications in strawberry production have been published in International J. Fruit Science. Objective 5.Findings were disseminated at the (i) Southeast Regional Fruit and Vegetable Conference, Savannah, GA(oral), (ii) the Mid-Atlantic Strawberry Education Program, Virginia Beach, VAin February 2020(oral), (iii) videos made at the Hampton Roads Agricultural Research and Extension Center, Virginia Beach, VAin June 2020and shared on social media, (iv)The American Society for Horticultural Science Annual Conference, August2020(oral), (v)preplant strawberrygrower meetings held via zoom/Facebook live, (vi) the Virginia Strawberry Association Newsletter in Fall 2019, Winter 2019/20, and Summer 2020(written), vii) Small Fruit NewsSmall Fruit News Posts Southern Region Small Fruit Consortium (smallfruits.org)in Summer 2020.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Growing Great Strawberries in the Southeast Region: Lessons from Variety Evaluation Trials. Southeast regional fruit and vegetable conference, Savannah, GA, 10 Jan 2020
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Samtani, J, S. Das, and J. Rajevich. 2020. Evaluating supplementary nutrients to improve strawberry fruit quality and yield. International Journal of Fruit Science, 20:1029-1038. DOI: 10.1080/15538362.2020.1774470
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Liu,D., J. Samtani, C. Johnson, D. Butler, and J. Derr. 2020. Weed control assessment of various carbon sources for anaerobic soil disinfestation. International Journal of Fruit Science, 20:1005-1018.doi=10.1080/15538362.2020.1774472
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Fernandez, G., Pattison, J., Perkins-Veazie, P., Ballington, J. R., Clevinger, E., Schiavone, R., Gu, S., Samtani, J., Vinson, E., McWhirt, A., & Chac�n, J. (2020). Liz and Rocco Strawberries, HortScience 55:597-600.
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Liu, D., Samtani, J., Johnson, C., Zhang, X., & Butler, D. (2020). Effect of brewers spent grain, distillers dry yeast and reduced amendment rates for anaerobic soil disinfestation on weed and Pythium suppression. In Hortscience Vol. 55 (pp. S206). Online: American Society for Horticultural Science.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:Target audience included strawberry growers, agriculture and natural resources agents, students, faculty from other institutions, high-school teachers, community garden leaders and coordinators, and master gardeners. These stakeholders come from various socio-economic backgrounds and races and are often underserved. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Hands-on training, work experience, and data entry skills were provided to a minority group undergraduate student (Objective 1). Hands-on training, work experience, data entry, writing and outreach skills were provided to a Ph.D. student also from a minority group (Objectives 1 and 5). A field day was hosted in May 2019 at the Hampton Roads AREC in Virginia Beach, VA where growers were invited and got to see first-hand, the different non-fumigant treatments and cultivars during the fruiting season. Growers and berry consumers also had the opportunity to taste berries from different cultivars and germplasm (Objective 2 and 5). How have the results been disseminated to communities of interest?Findings were disseminated through presentations at the (i) 9th North American Strawberry Symposium in February 2019 (oral and poster), (ii) the Mid-Atlantic Strawberry Education Program in February 2019 (oral), (iii) at the Virginia Urban Agriculture Summit in April 2019 (oral) (iv) at Delaware State University, College of Agriculture Science and Technology in April 2019 (oral) (v) Hampton Roads Agricultural Research and Extension Center Field Day in May 2019 (oral and written) (vi) The American Society for Horticultural Science Annual Conference, July 2019 (oral and poster) (vii) three preplant strawberry grower meetings held in Virginia Beach, Westmoreland and Charlottesville respectively in August 2019 (oral) (viii) the Virginia Strawberry Association Newsletter in Spring 2019 (written). What do you plan to do during the next reporting period to accomplish the goals?Publish four peer-reviewed papers (Objectives 1, 2 and 4). These are currently in review. Present findings at the 2020 American Society for Horticultural Science Annual Conference, Southeast Regional Fruit and Vegetable Conference, at the preplant strawberry meetings in Virginia and the Mid-Atlantic Strawberry School. Initiate studies and collect data pertaining to Objectives 1 and 3. Work with graduate and undergraduate students, agents and stakeholders to better understand impact of this study.

Impacts
What was accomplished under these goals? Objective 1. Our initial greenhouse studies showed that there is potential to reduce dose rates of locally available C sources such as brewer's spent grain (BSG) in ASD by the addition of yeast to the treatments. Pest efficacy equivalent to a full C dose rate is possible through this combination of reduced rate of C source and distiller's yeast. The two reduced rates of BSG alone were less effective in providing weed control as compared to the full dose rate of BSG, but the two reduced rates of BSG + yeast and the full rate of BSG had significantly better pest efficacy than nontreated control ± yeast treatments. In the open-field conditions our initial findings indicate that neither brewer's spent grain dosage rate, nor yeast, had an effect on the total weed density and biomass. However, weed density and biomass in ASD treatments and Pic-Clor 80 (fumigant) were significantly lower than the untreated control. Objective 5.Findings were disseminated at the (i) 9th North American Strawberry Symposium in February 2019, (ii) the Mid-Atlantic Strawberry Education Program in February 2019, (iii) at the Virginia Urban Agriculture Summit in April 2019 (iv) at Delaware State University, College of Agriculture Science and Technology in April 2019 (v) Hampton Roads Agricultural Research and Extension Center Field Day in May 2019 (vi) The American Society for Horticultural Science Annual Conference, July 2019 (vii) three preplant strawberry grower meetings held in Virginia Beach, Westmoreland and Charlottesville respectively in August 2019 and (viii) published in the Virginia Strawberry Association Newsletter in Spring 2019.

Publications

• Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Liu, D., J. Samtani, J.F. Derr, D.M. Butler, C. Johnson. 2019. Weed Control Assessment of Anaerobic Soil Disinfestation Treatments Using Brewer's Spent Grain and Distiller's Yeast in Strawberry Annual Hill Plasticulture Production. 2019 ASHS Annual Conference. https://ashs.confex.com/ashs/2019/meetingapp.cgi/Paper/30515
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Liu, D., J. Samtani, J.F. Derr, D.M. Butler, C. Johnson. 2019. Weed Control Assessment Utilizing Brewers Spent Grain, Paper Mulch and Cover Crops As Carbon Sources for Anaerobic Soil Disinfestation. 2019 ASHS Annual Conference. https://ashs.confex.com/ashs/2019/meetingapp.cgi/Paper/30506

Progress 01/01/18 to 09/30/18

Outputs
Target Audience:Objective 2. Findings were disseminated at the preplant strawberry grower meetings held in Virginia Beach, Westmoreland and Charlottesville in July 2018 and at the regional strawberry preplant meeting held on Aug 14 in Nashville, NC. These meetings are targeted towards strawberry growers, from various socio-economic backgrounds, races and are often underserved. We also target farmers and nutritionists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Hands-on training, work experience, and data entry skills were provided to a minority group,undergraduate student (Objectives 2, 4). Hands-on training, work experience, data entry and writing skills were provided to a Ph.D. student also from a minority group (Objectives 1, 2 and 4). A field day was hosted on May 22 at grower site in Virginia Beach, VA where growers were invited and got to see first-hand, the different cultivars and germplasm in fruiting season. Growers and berry consumers also had the opportunity to taste berries from different cultivars and germplasm (Objective 2). How have the results been disseminated to communities of interest?Findings were disseminated at the preplant strawberry grower meetings held in Virginia Beach, Westmoreland and Charlottesville in July 2018 and at the regional strawberry preplant meeting held on Aug 14 in Nashville, NC through PowerPoint presentations (Objective 2). A copy of the regional strawberry preplant meeting is posted on the site: https://ext.vt.edu/small-fruit.html What do you plan to do during the next reporting period to accomplish the goals?Publish two peer-reviewed proceeding papers (Objectives 1 and 4). Present findings at 2019 North American Strawberry Growers Assn. and 9th North American Strawberry Symposium meeting (Objectives 1 and 4). Collect data on Objective 1. Work with graduate and undergraduate students, agents and stakeholders to better understand impact of this study,

Impacts
What was accomplished under these goals? Research conducted this year found that several carbon (C) sources evaluated for anaerobic soil disinfestation (ASD) under greenhouse conditions had the potential to control weeds and provide results comparable to rice bran, a standard C source used for ASD. Application of distiller's yeast to full dose of C source improved weed control efficacy over C source application alone, regardless of C source.Based onthese findings,we are interested in further evaluating locally available, cheap C sources such as brewer's spent grain in field conditions (Obj. 1). Through on-farm cultivar and germplasm evaluation trials, we found that Ruby June cultivar and two NCSU advanced germplasms show potential for Virginia climactic conditions (Obj. 2). NCS10-038 and 'Ruby June' had larger berries than 'Chandler'. NCS10-156 had the high­est Total Soluble Solids (TSS) value, an indicator of berry sweetness. 'Ruby June' fruits also had higher TSS value than 'Chandler' and 'Camarosa'. Fruits of 'Camarosa' and NCS10-156 were most firm.

Publications