Final report for LNE21-433R
Project Information
A major and persistent challenge in Northeastern (NE) cranberry production is fruit rot disease. Deliveries exceeding 12% rot incur heavy penalties, while those above 20% are rejected outright by handlers (processing industry). Historically, when Massachusetts (MA) cranberry acreage was dominated by native cultivars (‘Early Black’ and ‘Howes’) and chemical control options were limited, growers relied on cultural practices such as late water (LW) flooding. This cost-effective, one-month spring flooding practice, recommended once every three years, was known to reduce fruit rot, suppress insects and weeds, and enhance fruit quality.
With the introduction of high-yielding hybrid cultivars, MA cranberry acreage shifted toward these newer varieties, which were more susceptible to fruit rot. The availability of broad-spectrum protectant fungicides (e.g., mancozebs/EBDCs since the 1960s and chlorothalonils since the 1980s) largely replaced cultural controls. Additionally, anecdotal reports linking LW to occasional yield losses contributed to its decline. To produce marketable fruit, growers now apply up to five fungicide treatments per season. However, interest in LW is resurging due to increasing pesticide restrictions in international markets, stringent fruit quality standards, pest outbreaks, and historically low cranberry prices. Recent stakeholder feedback indicates that while over 75% of decision-makers recognize LW’s benefits, they lack guidance on when and where to implement it effectively. Furthermore, no prior research has identified the key factors influencing LW outcomes. At extension meetings, more than 65% of growers expressed interest in adopting LW, provided they receive clear guidance and reliable decision-making tools.
We hypothesized that both biotic and abiotic factors influence LW effectiveness and that these factors can be quantified and evaluated. Our goal was to identify the critical variables driving LW success and develop a web-based, data-driven decision-making model (DMM) with user-friendly outputs for growers. To achieve this, our multidisciplinary team collaborated with growers over three years, studying 15 paired sites (LW vs. unflooded, five per year). We collected explanatory data (e.g., historical and current crop data, plant carbohydrate status, water quality) and response variables (e.g., yield, fruit quality). Additionally, we gathered records of fungicide and fertilizer use. Using R programming, we analyzed differences in yield, rot levels, and fruit quality parameters (firmness, total anthocyanin content, and berry weight) between LW and unflooded sites. By applying statistical analysis techniques, we examined predictor-response relationships to determine the key factors associated with successful LW, their relative contributions, and potential interrelationships.
To evaluate the relative importance of critical criteria (e.g., field characteristics, water quality, crop status, pest and yield history, and environmental conditions) that contribute to the short- and long-term outcome of late water (LW) floods and to develop a web-based, data-driven, decision-making model (DMM) that will generate grower-friendly outputs that promote appropriate LW use. A LW-DMM would improve cranberry grower confidence and facilitate increased adoption of this under-utilized practice. Farm profitability will be enhanced through sustainable cranberry production, increased revenue, and reduced pesticide applications. This could positively impact >420 farms in the Northeast (NE), affecting >16,000 acres of cranberries.
Massachusetts is the second-largest producer of cranberries in the U.S. with 5666 hectares (14,000 acres) in production, worth approximately $68,000,000 (USDA-NASS, 2018). MA cranberry farms (also referred to as bogs) are small in size with >70% of growers farm 20 acres or less. Fruit rot complex (associated with > dozen taxonomically diverse fungi) has been the major challenge in cranberry cultivation, resulting in 50-100% yield losses if not managed strategically. Fruit rot infected lots beyond 12% are heavily discounted and lots with >20% are not accepted by cranberry handlers. Historically when growers were largely cultivating native cultivars (Early Blacks and Howes) they relied on cultural management methods (late water flooding, pruning and sanding) for fruit rot. The native varieties are relatively low yielding and tolerant to fruit rot compared to the newer cultivars/hybrids. After the release of high-yielding hybrids such as BenLear (released in 1900) and ‘Stevens’ (released in 1940), the acreage shifted towards these hybrids. Based on the 2017 data sourced from OceanSpray, the largest grower co-operative representing approximately 60% of the MA acres, only 43.3% of the MA acreage is under native cultivars. 39.7% of the acreage is under Stevens and BenLears. When the effective chemicals (broad-spectrum chlorothalonils and mancozebs) were made available, growers started relying on them for managing fruit rot. In a typical commercial setting up to 5 fungicide applications/season are made, raising the cost of cultivation enormously.
For the past two decades, >90% MA cranberry acreage received chlorothalonil fungicides, making them key fruit rot management tools. In 2019, export markets targeted chlorothalonils for elimination and lowered maximum residue limits (MRLs) from 5 to 0.01 ppm. Since approximately 30% of the North American cranberry crop is marketed in the European Union (EU), most handlers imposed restrictions to meet international standards. Researchers and growers started the year 2020 considering the alternate options (the only other registered effective broad-spectrum fungicide group mancozebs; and single-site mode of action fungicides from FRAC group 3 & 11). On April 21, 2020, we received notification from the US trade policy office that the EU notified the World Trade Organization (WTO) of its intent to not renew the approval for use of mancozebs. Under this scenario, after February 2021, growers will be left only with Group 3 & 11 fungicides, fungal resistance of which is well documented in various cropping systems. Due to the intricacies of the fruit rot complex, it takes a long time and countless resources to screen and ultimately successfully secure new fungicide registrations. For the long term sustainability of the cranberry industry, it is essential that we reduce overreliance on chemicals and diversify the fruit rot management tool kit with eco-friendly, cost-effective, cultural measures. Especially due to the current historic low cranberry prices, rigorous fruit quality demands by handlers and pest outbreaks, there is a renewed interest in growers for low-cost, sustainable measures.
LW has been previously evaluated and proven to reduce fruit rot, pests, weeds and improve fruit quality on native cranberry cultivars. We do not know if these data accurately describe the response of hybrids. Given the proper guidance and confidence, several growers are willing to adopt LW for fruit rot management. Previous researchers have focused on individual aspects of LW outcomes (e.g., cranberry insects, fruit rot, or non-structural carbohydrates) over a single cropping season. We propose a multi-year, multi-disciplinary study with a broad scope. We proposed to identify critical criteria that influence the favorability of LW using on-farm research data as well as the historical records to develop a DMM. If our DMM accurately predicts the risks and conditions that would maximize success with LW, pesticide inputs and the cost of cranberry cultivation would be significantly reduced.
For the past three growing seasons we studied 15 paired sites (late water held vs control sites) and gathered information on fruit quality, weather and cultural practices data. We are analyzing all the data now with an objective to develop a late water decision making model.
Cooperators
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
Research
2021 Studies:
In April 2021, five paired sites of Late Water (LW) flooding versus unflooded control beds of ‘Stevens’ were selected in collaboration with our Advisory Committee and willing Massachusetts cranberry growers. The objective was to evaluate the relative contributions and interrelationships of various field-level variables on LW outcomes, including intended benefits (e.g., reduced fruit rot incidence, improved fruit quality, and reduced cultivation costs) and potential negative effects on plant health and crop yield.
Each paired site was labeled as Late Water (LW) and Unflooded Control (CON):
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2021-LW-1 / 2021-CON-1: Plymouth
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2021-LW-2 / 2021-CON-2: Carver
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2021-LW-4 / 2021-CON-4: Wareham
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2021-LW-5 / 2021-CON-5: Wareham
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2021-LW-6 / 2021-CON-6: LW in Carver, CON in Middleboro (4 miles apart)
All other paired sites were within 0.25 miles of each other. Historical data on yield and fruit rot percentage from the past five years were collected from participating growers. At the selected bog sites, LW floods were held from April 15 to May 15. From May to August 2021, bloom progression between LW and unflooded bogs was recorded during regular site visits. In June and July, tissue samples were collected for nutrient content analysis and total non-structural carbohydrate (TNC) analysis. Additional samples were processed for the reproductive-to-vegetative upright ratio.
An official advisory committee meeting with key professionals and grower participants was held on June 4, 2021, to discuss project materials, hypotheses, and the proposed plan of action.
In late September 2021, fruit samples from all paired sites were collected. Between October and November 2021, fruit samples were analyzed for fruit rot percentage, yield, and quality. In December 2021, regional climate and weather datasets were collected for inclusion in data analysis.
2022 Studies:
In April 2022, two paired sites of ‘Stevens’ and three paired sites of ‘MullicaQueens’ were selected following the same methodology as in 2021.
Paired sites were labeled as Late Water (LW) and Unflooded Control (CON):
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2022-LW-1 / 2022-CON-1: Wareham
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2022-LW-2 / 2022-CON-2: Carver
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2022-LW-3 / 2022-CON-3: Carver
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2022-LW-4 / 2022-CON-4: Plymouth
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2022-LW-5 / 2022-CON-5: Lakeville
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2022-LW-6 / 2022-CON-6: LW in Wareham, CON in Carver (5 miles apart)
Historical data on yield and fruit rot percentage from the past five years were collected from growers. LW floods were held from April 8 to May 15, 2022. Site visits continued from May to August to monitor bloom progression. In June and July, tissue samples were collected for nutrient and TNC analysis, along with reproductive-to-vegetative upright ratio assessments.
A second advisory committee board meeting was held on April 8, 2022, to review project progress, timelines, and upcoming plans.
An in-person Bogside Workshop was conducted on September 12, 2022, attended by 26 participants. During this workshop, we presented findings on LW, including factors to consider before implementation, known benefits, risks, and management practices post-flooding. We introduced our vision for an LW decision-making model and an initial prototype. Growers received a handout summarizing the presented information.
In late September 2022, fruit samples were collected. Between October 2022 and January 2023, fruit samples were processed for fruit rot percentage, yield, and quality. In January 2023, regional climate and weather datasets were gathered for further analysis.
2023 Studies:
In April 2023, two paired sites of ‘Stevens,’ two of ‘MullicaQueens,’ and one of ‘CrimsonQueen’ were selected for study.
Paired sites were labeled as Late Water (LW) and Unflooded Control (CON):
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2023-LW-1 / 2023-CON-1: Wareham
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2023-LW-2 / 2023-CON-2: Plymouth
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2023-LW-3 / 2023-CON-3: Marion
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2023-LW-4 / 2023-CON-4: Wareham
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2023-LW-5 / 2023-CON-5: Carver
All paired sites were within 0.25 miles of each other. Historical yield and fruit rot data were collected, and LW floods were held from April 8 to May 15, 2023. Bloom progression was recorded from May to August. In June and July, tissue samples were collected for nutrient and TNC analysis, along with reproductive-to-vegetative upright ratio assessments.
An in-person Bogside Workshop was held on September 7, 2023, at UMass-Amherst-Cranberry Station. The workshop covered LW considerations, benefits, risks, and post-flood management practices. We demonstrated an improved draft of our LW decision-making model and presented findings from the 2022 field studies, providing growers with a summary handout.
In late September 2023, fruit samples were collected. Between October 2023 and January 2024, fruit samples were analyzed for fruit rot percentage, yield, and quality. In January 2024, regional climate and weather datasets were incorporated into the analysis.
2024 Progress:
We compiled cultural practice data from participating growers for the studied bogs. Additionally, we prepared tissue samples from all three study years for the final Total Non-Structural Carbohydrates (TNSC) analysis and standardized the protocol in collaboration with Dr. Jyostna Devi Mura.
2025 Progress:
From January to mid-March 2025, we analyzed all data to evaluate differences in fruit quality and rot between late water and unflooded sites. The analysis was conducted using R programming, and TNSC samples were processed.
Plans for Mid-March to June, 2025:
In the final stage of data analysis, we will evaluate the effects of late water on fruit quality, rot, and yield. Our goal is to determine the feasibility of a late water decision-making model, assess how best to present it to growers, and identify any necessary refinements for ease of access and use. The final results will be submitted to NE SARE by June 2025.
If our hypothesis proves correct and we successfully develop a decision-making model, we aim to extend this work beyond the project period by engaging additional growers interested in implementing LW. This will enable us to further validate the model, enhance its usability based on feedback from early adopters, and improve its predictive accuracy in assessing LW’s risk-benefit outcomes.
Results from the last three growing seasons are being analyzed for developing late water decision making model.
Final data is currently undergoing analysis and interpretation.
Education & Outreach Activities and Participation Summary
Educational activities:
Participation Summary:
Outreach Presentations:
- https://www.youtube.com/watch?v=_YvDCQn36i8 "200 Years of American Cranberry Domestication & Status of Fruit Rot Research". Presented for BioIngene Online Webinar.
- Leela Uppala_April 27, 2021 UMass Cranberry Station's Pesticide Safety Meeting "Cranberry Fungicide Options: A Review".
- Leela Uppala- November 19th, 2021 UMass Cranberry Station's Oversight Meeting.
- Leela Uppala- December 17th, 2021 Invited Seminar "Cranberry Disease Research" to University of Wisconsin.
- Leela Uppala, Salisu Sulley, Michael Nelson- April 8th, 2022. Late Water Advisory Board Meeting.
- Leela Uppala, Salisu Sulley, Michael Nelson- September 12th, 2022. Late Water Bogside Workshop.
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Uppala, L. S., Nelson, M. F., and Salisu, S. 2022. Studies to identify critical criteria impacting late water outcome in Massachusetts cranberry production and develop a decision-making model. American Phytopathological Society Annual Meeting. August 6th-10th, Pittsburgh, PA.
- Leela Uppala, Salisu Sulley, Michael Nelson- September 7th, 2023. Late Water Bogside Workshop.
- Leela Uppala- November 17, 2023 UMass Cranberry Station's Oversight Meeting.
- Leela Uppala and Salisu Sulley, -January 30, 2024, UMass Cranberry Station's Annual Update meeting- Cranberry Fruit Rot: Research & Solutions
- Leela Uppala- November 22, 2024, UMass Cranberry Station's Oversight Meeting.
- Leela Uppala and Salisu Sulley, -January 28, 2025, UMass Cranberry Station's Annual Update meeting- Cranberry Fruit Rot Research Updates
Learning Outcomes
The current increased awareness of outcomes of late water flooding in new generation cranberry hybrids. Provided data driven guidance for late water use.