Progress 09/15/23 to 09/14/24
Outputs
Target Audience:The target audience for this reporting period included cranberry growers in the United States; they were reached during grower-oriented field days and meetings. We focused on engaging growers, recognizing them as the primary stakeholders who stand to gain the most from the results of this research. Various extension and outreach activities were employed to engage crop consultants and fruit processors. We specifically targeted these allied industry members due to their close collaboration with growers and their frequent involvement in extension services. We reached out to researchers during national and international meetings, specifically targeting them to inform them of the expected outcomes of this project. Changes/Problems: Plant Physiology Based on the 2023 pilot study for acute heat stress, we conducted the first heating pulse at 45°C for 4 hours on both Mullica Queen and Stevens cultivars at pea size stage of fruit development. However, signs of damage were observed after the treatment: leaves changed from a healthy dark green to a pale green-yellowish color, and the fruit appeared shriveled. These results indicated that the treatment conditions were too extreme. In consequence, we repeated the initial treatment on untreated plots, adjusting the temperature to 40°C and reducing exposure time to 2 hours. With these adjustments, we successfully induced fruit rot without visibly affecting plant physiology. Based on this experience we have decided to perform the acute heat stress treatments at 40° for 2 hours going forward. Plant Pathology Due to timing and distance to fields in Bandon, OR, from Corvallis, OR, the environmental sensors were not placed in fields this year until sampling for bloom occurred.We were unable to locate a third Mullica Queen bed to sample this year (all beds are commercial and require grower consent for sampling), and will try to find a grower that will allow us to sample a Mullica Queen bed in 2025. The drought conditions (NJ) caused some problems with production of fruit but with increased irrigation and maintenance of elevated water tables the impact was minimal. What opportunities for training and professional development has the project provided? In Wisconsin, for the Physiology objective, Ryder and Michelle, were trained for work in the field as well in the lab. Both students learned how to set up and use temperature sensors, how to test them, and analyze using basic statistics the data obtained with the sensors. They also received training in the use of scientific software, image J, to measure fruit cuticle thickness in light microscopy images of fruit thin sections. They also were trained to perform basic statistics analysis and create graphs to present scientific data. Ryder learned how to operate a freeze dryer as well as pulverizing fruit tissue for chemical analysis. In addition, Mirielle was trained to perform activities related to the project in field conditions, including setting up OTCs, operate generators, and collect phenological data from plots to be treated. She also received training in the making, maintaining and repairing micro thermocouples to measure internal fruit temperature in field conditions. She also received training in how to operate portable systems (Ciras 3) to collect physiological data, including carbon assimilation and stomatal conductance, from cranberry plants under long-term heat stress. At the laboratory, she learned how to use light and dissecting microscopes and collect fruit images to be analyzed by image J. She also learned how to do free hand sections of epidermis of cranberry fruit, collect images and measure cuticle thickness. Jenny Bolivar-Medina, provided the training to the participant students, in the areas mentioned above, as well as instructed them in basic laboratory practices, record observations and save experimental data. Eithan Pozas Rodriguez led the plant pathology objective in Wisconsin and gained training in fungal isolation and detection techniques. He alsodeployed the shade experiment (obj. 1.3) and analyzed rot incidence across the treatments. He also mentored an undergraduate researcher, Daniel Ortega, who processed fruit from Wisconsin and Washington samples for fruit rot fungi detection. He received training in fungal culturing, DNA extraction and PCR techniques. Technician Fabian Rodriguez Bonilla supported fungal detection methods in the laboratory for Objective 1. In addition, they were able to participate in professional development courses offered by UW-Madison, including topics related to purchasing card, bystander intervention, cybersecurity, and training related to R program for statistical analysis. One graduate student and one undergraduate worked on this project at Rutgers. The undergraduate will be joining Rutgers in PI Oudemans lab as a graduate student in January 2025. With the USD-ARS, a postdoctoral research associate continued their training opportunity through the ORISE program. This postdoc was trained on methods of analyzing multi-environment genotypic evaluation data in cranberry and will assist in collecting and analyzing data on organic acid content in developing cranberry fruit. The postdoc attended a multi-day training session on statistical analysis of plant breeding data in St. Paul, MN in June 2024. In Massachusetts, the Plant Physiology group had an undergraduate summer scholar who was trained on the project. The postdoctoral research associate presented the nitrogen work at an international conference on plant nutrition of fruit crops in Wenatchee, WA. Plant Pathology group hired a summer helper, a high school student leveraging some other available funds and provided training on lab techniques such as plating, pure culturing, DNA extraction. How have the results been disseminated to communities of interest? Wisconsin Cranberry Board research round table meeting November 15, 2023. Project updates were presented to growers. We participated in the Cranberry Research Station Filming Project organized by the Cranberry outreach specialist on July 11, 2024, to present research advances from teams working on cranberry studies to Wisconsin cranberry growers. While the experiment was running, we presented the goals of the project and briefly demonstrated how we were conducting the experiments. 1/30/24-Presented at Cranberry School (grower/industry meeting in Bandon, OR) for the Oregon Cranberry Grower's Association, including results from 2023. 7/19/24-Presented to the Virtual brown bag (Zoom) led by Allison Jonjak of University of Wisconsin-Madison, focusing on bloom results from 2023/2024. 8/1/24-Presented at Washington Cranberry Field Day (grower/industry meeting in Long Beach, WA), including results from 2023. A poster on analyzing phenotypic data in cranberry evaluation programs (for traits including fruit rot) was presented at the 2023 ASA-CSSA-SSSA International Annual Meeting in St. Louis, MO. A presentation was given at the 12th International Vaccinium Symposium in Halifax, Nova Scotia. Results of the research has been communicated through presentations and proceedings for meetings of the American Cranberry Growers Association. We presented the results at the crop summit, annual grower, and professional scientific meetings. The initial data set has been accepted for publication in a peer-reviewed conference proceeding for dissemination to the broader scientific community. A demonstration on cranberry fruit rots was presented during laboratory tours of the USDA ARS Horticultural Crops Disease and Pest Management Research Unit on 13 November 2023. A poster on cranberry fruit rot research was presented at the Northwest Center for Small Fruits Research on 14 November 2023. The first SAME newletter was delivered to 134 subscribers, including growers and fruit processors, in April 2024. What do you plan to do during the next reporting period to accomplish the goals? Objective 1 - Pathology Objective Continue sampling at bloom, pea-sized, blush, and harvest for each of the five Oregon fields, sort & record berries, and isolate/identify outgrowing fungi at each stage, just as in 2023 & 2024. We will also present results at the Bandon, OR "Cranberry School" in January 2025. Blush and Harvest Sample Analysis: Fungal isolation from these samples will be performed, followed by DNA extraction for subsequent molecular identification. Storage Rot Observations: Ongoing monitoring of healthy fruit stored at room temperature for signs of rot will continue, with findings recorded periodically. Shading Experiment Data Analysis: The processed harvest samples from the shading experiment will be analyzed to evaluate the effect of different shading durations on cranberry fruit quality and rot. An additional year of shade experiments may take place in Wisconsin to support the data collected in 2024. Fungicide Sensitivity Studies: We plan to study fungicide sensitivity variations (if any) among the pure culture isolates. We plan to share the results with growers during our annual update meetings. Objective 2 - Physiology We will conduct the experiments following the same procedures used in the 2024 growing season. After evaluating the protocols for extracting anthocyanins, phenolic compounds, and reactive oxygen species (ROS), we will determine if any adjustments are needed. The results from the current data analysis on yield and fruit chemical composition will be presented at winter grower meetings. Additionally, the analyzed data will be shared in the newsletter in the SAME project website, making it accessible to the general public. We will continue with field experiments and data collection in the third year. Samples collected from the study will be analyzed in the laboratory. We will share the results with growers during our crop summit and annual update meetings. We also plan to prepare manuscripts for publication in peer-reviewed journals for wider dissemination to the scientific community. Objective 3 - Breeding Objective 3.1: A manuscript describing the statistical analysis of data from cranberry regional variety evaluation nurseries will be submitted for publications; additional phenotypic data will be collected from regional trials in NJ, OR, and WI; statistical approaches for measuring phenotypic stability will be evaluated.Objective 3.2: Fruit samples will be collected every 2 weeks during the 2025 growing season. Fruit will be evaluated for organic acid content and fruit rot severity. Objectives 3.1 and 4.2. Weather monitoring equipment will be deployed to collect in-bog data on environmental conditions; this data will be used to assess genetic variability in response to environmental stress events and identify relevant environmental variables that will be included as predictors in a disease forecasting model. Objective 4 - Economics and Extension In the next reporting period, we will conduct our annual re-assessment regarding Objective 4, Goal 1. In addition, we will begin to identify any notable or characteristic aspects of different fruit rot management practices that will impact farmer uptake for Objective 4 Goal 2. While we do not expect that experimental design or data collection phase will begin in this reporting period, we will begin to work with the rest of the project team to cross-pollinate between social and life science research methodologies so that the social science research tools and methods (including limitations and possible outcomes) are familiar to the life sciences researchers in subsequent periods. In the next reporting period, the Extension objective will focus on more outreach efforts with stakeholders. This includes 2 more newsletter issues, a webinar on project findings, and a virtual symposium with members of the Advisory Panel and the Extension Network. The SAME Team will also meet at the 2025 North American Cranberry Research and Extension Workers meeting to discuss project progress.
Impacts
What was accomplished under these goals?
Objective 1 - Plant Pathology Oregon - Sampling occurred at bloom, pea-sized, blush, and harvest stages for each of the five Oregon fields (3 Stevens cultivars and 2 Mullica Queen cultivars). To date, outgrowing fungi have been isolated at each stage from blush through harvest, cranberry fruit rots were identified, and results were recorded, including berry weights at harvest, and rot incidence at harvest and blush. This year, field rot incidence at harvest ranged from 2.1% to 7.3% among the five fields. Currently, 1416 cultures have been isolated from samples over the 2024 season with known fruit rots identified. Many early season cultures are being saved for molecular and fungicide testing, as will isolates from later season sampling. Wisconsin - Flowers and fruits were collected from three Mullica Queen beds and three Stevens beds at the four predetermined phenological stages of bloom, green fruits, blush, and mature fruits. All fruits were processed using culture isolation techniques and DNA was extracted for downstream sequence-based identification. Shade experiments were completed at the Wisconsin Cranberry Research Station. Fungicide applications were made at 20% and 80% in-bloom and shade treatments were installed shortly after fruit set in early July, and it was deployed for over two months during the growing season in July, August, and September. New Jersey - To develop an understanding of the species composition of cranberry fruit rot over 2000 berries were cultured from 15 farms. The predominant species was Colletotrichum fructivorum, which causes fruit rot around harvest. An early rot species (Phyllosticta vaccinii) was also quantified. Seven novel cranberry fruit rot resistant genotypes were evaluated under different fungicide regimes as compared to a high yielding, susceptible cultivar (Stevens). Three genotypes (05-64-9, 12-30-24 and 14-31-142) performed as well as or better than the cultivated variety 'Haines" especially under reduced fungicide use. These new genotypes show strong potential as new cultivars. Massachusetts - The primary objectives were to analyze the effects of shading on cranberry growth and quality and to assess the incidence of fruit rot at different growth stages. The work included sample collection, fungal isolation, DNA preparation, and storage rot observation. Weather data, including temperature, relative humidity, and leaf wetness, were recorded to monitor environmental conditions influencing the experiments. Samples were collected at four critical growth stages to assess fungal development and fruit rot progression across these growth stages. Bloom: June 21, 2024; Pinheads: July 15, 2024; Blush: August 19, 2024 and Harvest: October 8, 2024.These samples were processed to assess the percent rot at each stage. Objective 2 - Physiology (2.1) During the 2024 growing season, we conducted both long-term and acute (short-term) heat stress experiments on two commercial cultivars, Mullica Queen and Stevens. Wider and shorter OTCs were used for the long-term heat stress, as they better retain higher midday temperatures, whereas narrower and taller OTCs were used to induce acute heat stress.We established 4 m2 plots for both the long-term and short-term experiments. We set up 4 OTCs and 4 control plots per cultivar. From the time the OTCs were established until just before fruit harvest, canopy temperature and relative humidity were recorded every 10 minutes. Four times during the growing season carbon assimilation and stomatal conductance was measured in fruiting uprights in OTCs and control plots using CIRAS- 3 Portable photosynthesis system. When fruit had set and reached pea size stage, we inserted a micro thermocouple through the calyx to record internal fruit temperature until harvest. For the acute heat stress experiment, we applied four treatments to cranberry plots at four phenological stages of fruit development: pea size, green, blush, and red berry stages. Each treatment involved exposing the plants to 40°C for two hours, beginning at specific phenological stages, resulting in a varying number of "pulses" or instances of heat stress. The first treatment consisted of four pulses applied at all four stages (pea size, green, blush, and red berry). The second treatment involved three pulses at the green, blush, and red berry stages. The third treatment consisted of two pulses, applied at the blush and red berry stages. The final treatment included a single pulse given only at the red berry stage.To induce acute heat stress, we used a patio lamp with 1600 watts infrared heating elements placed on top of the OTC. Inkbird Temperature Controller was set up to keep the temperature at 40°C ± 0.5°C for two hours. Samples we used to evaluate total yield, percentage of rotten fruit vs healthy fruit, fruit morphology (length, width, cuticle thickness), and fruit chemical composition, including total anthocyanins, and phenolic content, as well as sugar, organic acids, amino acid, and reactive oxygen species (ROS). In addition, plant material was collected from the long-term heat stress experimental plots to evaluate plant traits including fruiting upright density, upright length, apical floral bud formation, and stomatal conductance density, and leaf area and thickness. (2.2 & 2.3) We conducted the second season of experiments to understand the effect of light stress and nitrogen on plant and fruit rot development. The light stress study consists of two experiments. The first experiment studied the effect of reduced light stress over the growing season on fruit rot development. The second experiment studied the effect of fruit exposure to sunlight at different stages of fruit growth. The nitrogen study looked at the impact of fertilizer application on yield and fruit quality. We evaluated the incidence of fruit rot with an increase in fertilizer N application. The data from the second season of experiments is still being analyzed. Objective 3 - Breeding Historical phenotypic data from regional variety evaluation nurseries located in New Jersey, Oregon, British Columbia, and Wisconsin were cleaned and curated to enhance their usability. Preliminary statistical analyses were completed to establish robust models for future evaluations. During the 2024 field season, critical data on fruit yield, quality, and rot incidence were collected from regional trials in NJ, OR, and WI. Additionally, fruits from cranberry resistance trials and genotypes with varying organic acid levels were harvested and stored for detailed chemical analysis. To support these efforts, weather monitoring equipment was installed in research bogs in NJ to track environmental variables that may contribute to fruit rot, providing a foundational understanding of how environmental factors interact with genetic traits. Objective 4 - Economics and Extension Obj 4, Goal 1. Interviewed each project Objective team to develop written plans that align the economic research plan with different CFR management practices and possible interventions based on research outcomes to financial and behavioral models of grower behavior. It was determined that field trial results will be needed to estimate impacts on growers' costs from different fruit rot management practices, as opposed to ongoing field data collection to assess input costs. The team agreed to check in in March 2025 to re-assess, but not withstanding major changes to field trial activities we expect that this goal will be accomplished toward the end of the project when field trial results are available. Under the Extension-focused objective we continued to build our team website and published our first newsletter (https://sameproject.wisc.edu/wp-content/uploads/sites/386/2024/04/SAME-Newsletter-Issue-1-April-2024-1.pdf). The newsletter currently has 134 subscribers.
Publications
- Type:
Other
Status:
Published
Year Published:
2024
Citation:
Oudemans, P. Scald in cranberry fruit: Part 1 Understanding Causes.Rutgers University.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Brian Makeredza, Peter Jeranyama, Giverson Mupambi and Leela Uppala. 20024. Nitrogen fertilizer affects cranberry fruit quality. Acta Horticulturae.
- Type:
Other Journal Articles
Status:
Published
Year Published:
2023
Citation:
Futurum Magazine. How can we improve cranberry production? November 2023. Issue 23 p. 60-63.
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Progress 09/15/22 to 09/14/23
Outputs
Target Audience:The target audience for this reporting period included cranberry growers in the United States; they were reached during grower-oriented field days and meetings. We focused on engaging growers, recognizing them as the primary stakeholders who stand to gain the most from the results of this research. Various extension and outreach activities were employed to engage crop consultants and fruit processors. We specifically targeted these allied industry members due to their close collaboration with growers and their frequent involvement in extension services. We reached out to researchers during national meetings, specifically targeting them to inform them of the expected outcomes of this project. Changes/Problems:In Wisconsin, for the short-term heat study (Objective 2.1), after running the pilot study during the growing season of 2023, we recorded internal berry temperatures during the warmest days of the summer of over 43°C. The original research proposal for this short-term heat stress study consisted in exposing the berries to a in situ heat stress events of 4 h to a constant berry temperature of 35 °C, 40 C, and 45 °C. Since under normal growing conditions, berries in the field already experienced over 40°C, we have decided to only use the 45 °C as the temperature we will test for short term heat stress. In addition, we had originally planned to do single short term heat stress events applied at four berry developmental stages: pea size berry, green fruit stage, blush stage, and full red color. However, since our preliminary data collected during the 2023 growing season show that multiple short term heat events happen as berries develop, we have decided to change our study from discrete short term heat events to cumulative short term heat stress applied to the same experimental plots. This resembles more closely what happening during the growing season. We will apply the 4-hour heat stress to a constant internal berry temperature of 45 °C in the following treatments. Treatment 1: heat stress will be applied at pea size berry, green fruit stage, blush stage, and full red color. Treatment 2: heat stress will be applied at green fruit stage, blush stage, and full red color. Treatment 3: heat stress will be applied at blush stage and full red color. Treatment 4: heat stress will be applied at full red color, and finally a control treatment that will not be subjected to a short-term heat stress. The proposed long-term heat stress study consisted of 2 treatments: a control and an active heating area that would continuously be raised 2 and 4 ?C over the ambient temperature using an open-top chamber (OTC), with each treatment consisting of 4 replicates. However, the Wisconsin Cranberry Research Station does not have access to AC power to be able to actively heat the OTCs, and although we explored several options to actively heat the OTCs during our pilot study in 2023 with other sources of power, these were not enough to actively heat the OTCs for 24 hours. As part of the pilot study, we also monitored the temperature inside the OTC without providing active heating during an 8-week period. We observed that even if the OTCs are not actively heated, temperatures inside the chambers can consistently achieve more than 5 degrees Celsius higher than outside during daytime, and during night the chambers will hold about 1 degree Celsius higher than outside temperature when there's low wind. Based on this preliminary data, and the fact that we are not able to access AC power to actively heat the chambers, we will adjust our long-term heat stress study to passively heat cranberry vines inside the OTCs. For the shade experiment (Objective 1.3), we will expand the number of replicated deployed for each treatment while decreasing the number of fruits collected. This change is implemented to enhance the statistical power of the experiment and minimize the unnecessary labor involved in berry enumeration. In Oregon, we do not have experimental cranberry research plots. Consequently, all of our samples are from grower's beds. The growers kindly provide fungicide application records, but we are unable to do pairwise comparisons between non-treated blocks and fungicide treated blocks. Nonetheless, the data from the grower's beds is valuable and of primary importance to monitor the emergence of resistance of cranberry fruit rot pathogens to single-site fungicides. In New Jersey, a post-doc will be hired in summer 2024. Although this is behind schedule the individual will be hired at a time when the project is established, and productivity will be higher. Due to uncertainty surrounding the continuation of federal appropriations in FY24 for the USDA, Agricultural Research Service, travel requests were not approved, and data could not be collected from sites hosting regional genotypic evaluation trials (Objective 3.1). In Massachusetts, two factors have impacted Dr. Jill Fitzsimmons portion of the project so far. First, there were major budget cuts to the relevant portions of the project, which resulted in effort spent to reframe project activities and deliverables. Second, due to unanticipated administrative factors, the project funding was received by UMass about half-way into the project year. In addition to losing about 6 months of project time, the timing was difficult as team members needed to prioritize field work and not collaboration on economic work. Those factors have impacted all aspects of the plan, approach, methods, timeline, and objectives. That said, we are in a good place to move the new activities and deliverables forward in the coming reporting period. With reference to other objectives or other investigators studies, we have no major changes to the protocols and experiments outlined in the proposal. What opportunities for training and professional development has the project provided?In Wisconsin, a PhD graduate student was recruited and started in the department of plant pathology at UW-Madison. This student is being trained in applied plant pathology research and fungal identification approaches. Two undergraduate researchers were trained in microbiological culturing methods and microscopy. In the department of horticulture, a Research scientist was recruited to conduct heat stress experiments for Objective 2 and will lead data collection and analysis for this study. In New Jersey, a postdoctoral research associate was hired through the ORISE program (USDA ARS). This postdoc will be trained on methods of analyzing multi-environment genotypic evaluation data in cranberry and will assist in collecting and analyzing data on organic acid content in developing cranberry fruit. Two interns have been trained to utilize microbiological culturing methods to isolate fungi from cranberry tissues. All aspects of collecting, surface sterilizing, sterile technique as well as media preparation and autoclave function were covered. In Massachusetts, graduate students from the UMass Plant Biology Program visited during harvest and this afforded us an educational opportunity to discuss the projects and basic aspects of applied research. We have trained two postdoctoral research associates involved in the project. Postdoctoral researcher Dr. Brian Makeredza was trained in leaf gas exchange analysis using a CIRAS 3 leaf agas analyzer and LICOR -6800, Portable Photosynthesis System. We have also started to train Dr. Makeredza on ultra-performance liquid chromatography (UPLC) analysis of biochemical compounds related to fruit rot development. Postdoctoral researcher Dr. Salisu Sulley got trained in the characterization of cranberry fruit rot fungi using multiplex PCR. He is also being trained on the protocols involving the study of fungicide sensitivity variations among the fungal isolates collected from current study. How have the results been disseminated to communities of interest?Presentations about this SCRI grant and cranberry fruit rot were given to the stakeholder and research communities in Bandon, OR at 'The Cranberry School' on 22 March 2023, and to growers in Wisconsin Dells, WI at the 'Wisconsin Cranberry School' on 18 January 2023. What do you plan to do during the next reporting period to accomplish the goals?Objective 1.1. In Oregon, for the next reporting period in 2024, we will sample the same beds and potentially add a third Mullica Queen bed next spring. Samples will be collected from each bed from bloom to harvest as in the first year. Fungi will be isolated from symptomatic berries and identified based on morphology and/or ITS sequence or multiplex PCR. Preliminary results and progress will be presented to stakeholders at the 2024 "Cranberry School" in Bandon, OR. In Wisconsin, New Jersey, Washington, and Massachusetts collections will take place in the same cranberry varieties at the same frequency as occurred in the first year. Results will be shared at grower meetings during the winter in the states where research is being conducted. Objective 1.2 - Fungicide sensitivity testing will continue in the second year of the project utilizing fungal isolates collected in objective 1.1. Objective 1.3 - The shade experiment will be repeated in 2024 in Wisconsin, New Jersey, and Massachusetts. Objectives 1, 2.2, 2.3, and 4. In Massachusetts, we are going to repeat the field experiments for the fungal population structure characterization, role of shade, fungicide use, light stress and nitrogen studies for their effects on plant and rot development. Lab analysis of the samples will be conducted. We will also send some samples to UW Wisconsin. We are going to run samples on UPLC for total non-structural carbohydrates. Some samples will be sent for Δ13C analysis and nutrient composition. We plan to study fungicide sensitivity variations (if any) among the isolates. We plan to share the results with growers during our annual update meetings. Dr. Fitzsimmons will work with full research team to develop written plans for each CFR management practice in the project that identify potential costs, grower behavioral considerations, barriers, and policies with potential to impact implementation. Objective 3.1: A sample of the historical regional variety trial data will be analyzed for genotype-environment interactions; an analysis workflow will be developed for deployment when analyzing the complete dataset; additional phenotypic data will be collected from regional trials in NJ, OR, and WI Objective 3.2: Fruit samples will be collected every 2 weeks during the 2024 growing season. Fruit will be evaluated for organic acid content and fruit rot severity. Objectives 3.1 and 4.2. Weather monitoring equipment will be deployed to collect in-bog data on environmental conditions; this data will be used to assess genetic variability in response to environmental stress events and identify relevant environmental variables that will be included as predictors in a disease forecasting model. We will meet with the SCRI-SAME team members to discuss results and determine how to proceed next growing season.
Impacts
What was accomplished under these goals?
Under Objective 1 - Cranberry flowers and fruit were sampled throughout the growing season from June to September 2023 in'Stevens' and 'Mullica Queen' cranberries to evaluate the succession of fruit rot fungi (Obj. 1-1). A total of five to six beds were sampled per state in Wisconsin, New Jersey, Massachusetts, along the southern Oregon coast, and Washington state. Cranberry ovarysamples were placed on acidified PDA or V8 agar and outgrowing fungi were transferred to obtain single isolates. In Wisconsin and Washington state, fungal diversity decreased as cranberry ovaries developed and were collected during the growing season, with several key fruit rot pathogens identified from flowers during bloom. A greater number of unique isolates were identified from the 'Mullica Queen' variety compared to the 'Stevens' variety. In Oregon, fungi will be identified based on morphology and ITS-region sequencing. In NJ pathogenic fungi were detected mostly in rotted fruit in mid-August.Very low levels were found at bloom and mid-July. We anticipated finding higher levels because fruit infections take place during the bloom period, however, the fungi were either absent, present at very low levels or in a dormant state and not culturable. In Massachusets, data is still being analyzed from the culture-dependent analysis. In Oregon and Wisconsin, fungicide sensitivity assays (Obj. 1-2) have been started on several pathogens including Colletotrichum and Phomopsis. In New Jersey, Wisconsin, and Massachusetts, trials were conducted investigating the effect of shading on the expression of fruit rot (Obj. 1-3). We had hypothesized that because sunlight acts as a trigger for fruit rot expression shading would reduce the levels. Our trial was conducted using shade cloth (30% shade; 2 colors of shade cloth used in NJ and one color in Wisconsin and Massachussetts) and fungicides (no fungicide application or grower standard fungicide). In New Jersey, the results did not support the hypothesis and only the use of fungicides reduced fruit rot expression. In Wisconsin, there was a significant difference (α = 0.1) between the no shade-no fungicide treatment compared to the shade-fungicide treatment. The data collected in Massachusetts is still being analyzed. Under Objective 2- In Wisconsin, during the growing season of 2023 we did a pilot study to test two models of open top chambers (OTC) for the short- and long-term heat stress study (Obj. 2-1). The models differed in their height and width, which had implications on how warm the chambers would get during mid-day, and how fast the heat would dissipate by radiation to the atmosphere during the night. We tested both OTC models in a long-term heat stress pilot study using the cultivar Stevens at the Wisconsin Cranberry Research Station in Black River Falls, WI. We deployed both models in the field starting the second week of July (after bloom) until harvest the second week of September. We developed sensors to continuously monitor air and berry temperature inside the OTCs, as well as relative humidity. At the end of the season, we collected yield data comparing the two OTC prototypes and the control, and we found no differences in total yield or number of berries produced. We did not observe any differences among the OTCs and the control plots for vegetative growth. For the short-term heat stress pilot study, we tested three sources of heat lamps that provided 600, 900, and 1500 watts of energy. During the growing season we imposed more than 15 pulses of heat stress to a bed of cranberry of the cultivar Stevens, with the objective of refining the experimental set up so that the berries inside the chambers would be exposed to a 3-hour heat stress treatment in which berries achieved an internal temperature of 45 degrees Celsius. Based on the preliminary data collected during the 2023 growing season, we had to make some changes to our original experimental design. In New Jersey, the light stress study consists of two experiments (Obj. 2-2). The first experiment studied the effects of reduced light stress over the growing season on fruit rot development. The second experiment studied the effects of fruit exposure to sunlight at different stages of fruit growth. The nitrogen study (Obj. 2-3) looked at the effect of fertilizer application on yield and fruit quality parameters was assessed. We evaluated the incidence of fruit rot with an increase in fertilizer N application. Under Objective 3- Historical regional trial datafrom New Jersey, Wisconsin, Oregon, Washington, and British Columbia was collected. Data cleanup and organization was initiated. Under Objective 4- We began baseline discussion to connect cranberry fruit rot management practices to financial and behavioral models of grower behavior. Extension efforts began with the planning of the first newsletter with the project team (anticipated to be released in Year 2). Additionally, the project team, extension network, and several members of the advisory panel met during the North American Cranberry Research and Extension Worker conference to review current efforts and receive feedback.
Publications
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