Identifying Critical Criteria to Develop a Decision-making Model for Implementing Late Water Floods in Cranberry Production

Progress report for LNE21-433R

Project Type: Research Only
Funds awarded in 2021: $189,340.00
Projected End Date: 11/30/2024
Grant Recipient: University of Massachusetts
Region: Northeast
State: Massachusetts
Project Leader:
Dr. Leela Uppala
University of Massachusetts
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Project Information


        A major and persistent challenge affecting Northeastern (NE) cranberry production is fruit rot disease. Fruit deliveries beyond 12% rot are heavily penalized, and deliveries >20% rot are rejected outright by handlers (processing industry). When Massachusetts (MA) cranberry acreage was largely planted in native cultivars (‘Early Black’ and ‘Howes’) and effective chemical control options were not available, growers relied on cultural control by late water (LW) flooding. LW is an affordable 1-month spring flooding practice, recommended once in 3 years, and is known to reduce fruit rot, insects, weeds and enhance fruit quality.

       After the release of high-yielding hybrid/newer cultivars, MA cranberry acreage shifted towards these newer cultivars, which were more susceptible to fruit rot compared to native cultivars. The introduction of effective broad-spectrum protectant fungicides (mancozebs/EBDCs-ethylene bisdithiocarbamate from 1960s and chlorothalonils from 1980s), largely replaced cultural controls. Anecdotal association of LW to occasional yield losses also contributed to this shift. To produce marketable fruit, growers often apply up to five fungicides per season. Interest in LW is resurging due to the loss of key pesticides due to pesticide restrictions by international markets, rigorous fruit quality demands by cranberry handlers, pest outbreaks and historically low cranberry prices. Based on recent stakeholder feedback, >75% of decision-makers are aware of LW benefits but did not know how to decide when and/or where LW could be most beneficial. No previous research has determined which factors contribute to LW outcomes. In our extension meetings, >65% of growers expressed interest in implementing LW given the proper guidance and confidence.

        We hypothesize that biotic and abiotic factors affect LW results and that these factors can be quantified and evaluated. We propose to identify the critical criteria that drive the results of LW and develop a web-based, data-driven, decision-making model (DMM) that produces grower-friendly output. For this, our multi-disciplinary team will work collaboratively with growers for three years on 15 paired sites (unflooded versus LW, 5 sites per year) and collect data for explanatory (e.g., historic and present crop data, plant carbohydrate status, water quality) and response variables (e.g., yield, fruit quality). We will analyze data using crop simulation modeling and identify the critical factors that are associated with successful LW, their relative contribution and interrelationships, and develop a LW-DMM. A LW-DMM would improve grower confidence and facilitate increased adoption of this under-utilized practice. Farm profitability will be enhanced through sustainable production, reduced pesticide applications, reliable fruit quality and reduced penalties/load rejections.

        We will disseminate results to the grower-industry-scientist network through education outreach with fact sheets, peer-reviewed publications, digital resources (e.g., webinars, ScholarWorks, social media), and extension meetings. We will gather feedback from the Advisory Committee (AC) and early adopters on the initial model and integrate improvements.

Project Objective:

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.


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  • Dr. Michael Nelson (Educator and Researcher)
  • Dr. Peter Jeranyama (Educator and Researcher)
  • Dr. Casey Kennedy (Educator and Researcher)
  • Dr. Giverson Mupambi (Educator and Researcher)
  • Dr. Hilary Sandler (Educator and Researcher)
  • Dr. Anne Averill (Educator and Researcher)
  • Dr. Salisu Sulley (Educator and Researcher)


Materials and methods:

In April 2021, 5 paired sites of LW flooding versus unflooded control beds of ‘Stevens’ were selected in collaboration with our Advisory Committee and other willing MA cranberry growers to evaluate relative contribution and interrelationships of various field level variables on LW outcomes, both for intended benefits (e.g., reduced fruit rot incidence, improved fruit quality, reduced cost-of cultivation) and potential negative effects on plant health and crop yield. Each of the paired sites were labelled as Late Water/LW and Unflooded/Control/CON (2021-LW-1/2021-CON-1 were located in Plymouth; 2021-LW-2/2021-CON-2 were located in Carver; 2021-LW-4/2021-CON-4 were located in Wareham; 2021-LW-5 & 2021-CON-5 were located in Wareham; 2021-LW-6 is in Carver & 2021-CON-6 were located in Middleboro). Each of the paired site LW bog and unflooded controls were very close to each other (less than 0.25 miles distance) except LW-6 & CON-6 which were 4 miles apart. From all of the participating growers data pertaining (yield, fruit rot%) to participating bogs for the past five years was collected. Participating growers at the selected bog sites held late water floods from April 15 to May 15th. From May 15th to August 2021, all the sites were visited on a regular basis, bloom progression between late water and unflooded bogs were recorded. In June and July, from each of the sites tissue samples for nutrient content analysis and total non-structural carbohydrate analysis were collected. Samples were also collected and processed for Reproductive vs Vegetative upright ratio.

We had our first official advisory committee/key professionals/grower participants official meeting on June 4th to discuss the materials and methods of the project, hypothesis to be tested, proposed plan of action.

In Late September, fruit samples from all the participating paired sites were collected. In October and November, fruit samples were processed for fruit rot%, yield, fruit quality estimations. In December, regional spatial datasets of climate, weather were collected for inclusion in data analysis.

Research results and discussion:

One of the unexpected outcome of 2021 is heavy rain (>6 inches/night) in the first week of September resulting in submerged conditions in several bogs in Massachusetts. Due to this, the growers chose to harvest LW2/CON2 paired site earlier and we could not collect final fruit samples. At present results from 2021 are being analyzed with relevant statistical tools that could aid us identify critical criteria that drive the outcome of Late water floods. Some of the preliminary results from 2021 are presented below. These results suggest farm to farm variable responses to late water floods. We are also working with our advisory committee and MA cranberry growers to identify field sites for 2022 studies.

Participation Summary
5 Farmers participating in research

Education & Outreach Activities and Participation Summary

Educational activities:

5 Consultations
4 Webinars / talks / presentations

Participation Summary:

250 Farmers participated
5 Number of agricultural educator or service providers reached through education and outreach activities
Outreach description:

Outreach Presentations:

  1.  "200 Years of American Cranberry Domestication & Status of Fruit Rot Research". Presented for BioIngene Online Webinar.
  2. Leela Uppala_April 27, 2021 UMass Cranberry Station's Pesticide Safety Meeting "Cranberry Fungicide Options: A Review".
  3. Leela Uppala- November 19th, 2021 UMass Cranberry Station's Oversight Meeting.
  4. Leela Uppala- December 17th, 2021 Invited Seminar "Cranberry Disease Research" to University of Wisconsin

Learning Outcomes

250 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
5 Service providers reported changes in knowledge, attitudes, skills and/or awareness as a result of project outreach
5 Educators or agricultural service providers reported changes in knowledge, skills, and/or attitudes as a result of their project outreach

Project Outcomes

5 New working collaborations


No participants
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.