Progress 09/01/23 to 08/31/24
Outputs
Target Audience:The target audiences reached during this reporting period include the 10 fruit packers/growers where the project research is occurring; apple growers throughout the Mid-Atlantic (PA, MD, VA, NJ, and the Northeast); members of the LatinX community in Adams County, PA; Penn State Extension; University of Maryland Extension; agrochemical companies; and tree fruit researchers in academia, state and federal governments, and private industry. In addition, we reached an international audience through our podcast. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?For this project the team members attended Plant Health 2024, the annual meeting of the American Society of Phytopathology (APS), which was held in Memphis, TN July 27 - 30, 2024. In this meeting, results were discussed for Objectives 1 and 2 to the scientific community while networked with potential collaborators and colleagues in the field. How have the results been disseminated to communities of interest?The results were disseminated at the following meetingswhere the target audience was attending andpresentations were given: November 7, 2023, Harvest and postharvest practices for improving apple fruit marketability: Fruit quality and safety, University of Maryland Research and Education Center, Keedysville, MD (2 presentations and 1 poster) January 30, 2024, Mid-Atlantic Fruit and Vegetable Convention, Hershey, PA (2 presentations about postharvest apple diseases and their management (including fungicide resistance)and an applegrower panel to discusspostharvest apple diseases and their management) November 30, 2024, 99th Cumberland Shenandoah Fruit Workers Conference (1 presentation) July 27 - 30, 2024, Plant Health 2024, American Phytopathological Society of America, Memphis, TN February 2024: 2024 Winter Tree Fruit Schools (7 Pennsylvania with1 inSpanish; and 1 Maryland) Dr. Tree Fruit and Don Podcast Research was distributed in print: Pennsylvania Fruit News 2024 - 2025 Penn State Tree Fruit Production Guide What do you plan to do during the next reporting period to accomplish the goals?We will be completing the tasks outlined for Objectives 2and 3. In addition, four scientific papers are being prepared and are expected to be published in 2025. The tentative titles of the papers are: Castro J., Jurick W.M., 2nd, and Peter K.A. "A systematic survey of postharvest apple decay fungi in the Mid-Atlantic, USA" Castro J., Jurick W.M., 2nd, andPeter K.A."Categorizing inoculum sources of postharvest apple blue mold fungi as reservoirs of sensitive and fungicide resistant isolates" Castro J., Jurick W.M., 2nd, andPeter K.A."A survey of fungicide sensitivity and efficacy for postharvest apple decay fungi in the Mid-Atlantic, USA" Luciano-Rosario, D., Castro J., Peter K.A., Cox K.D., Fonseca J.M., Gaskins, V.L., Jurick W.M., 2nd (2024). Mold in, mold out: Harvest bins harbor viable inoculum that can be reduced using novel sanitation methods to manage blue mold decay of apples. Postharvest Biology and Technology (submitted)
Impacts
What was accomplished under these goals?
Objective 1. Inoculum transfer experiments were conducted to test the hypothesis if wood and plastic bin materials can serve as a direct source of inoculum to incite blue mold decay on wounded apple fruit. To test this, small wood and plastic materials were either inoculated with spore suspensions, mimicking production line dump tank water, which contains spores, or blue mold infected apple fruit tissue, present in harvest bins. Apples were wounded and positioned in direct contact with the inoculated materials and disease symptoms were recorded. After one week of exposure to the inoculated materials, apple fruits touching both wood and plastic showed disease symptoms when directly exposed to fruit macerate (representing blue mold infected fruit that have been observed pressing up against the interior of bin surfaces). In contrast, for the spore suspension treatment, wooden material did not incite blue mold, while in plastic material, only one apple developed symptoms. With this experiment, we showed that apple harvest bins can serve as a direct and viable source of inoculum for blue mold decay, expanding the current knowledge on this pathogen's disease cycle. After the packinghouse samplings were finished, a collection of pure cultures of the most frequent pathogens isolated from decayed apples was obtained. The morphological description, DNA sequencing and phylogenetic analysis of these cultures were completed (late 2023). Multiple fungi were identified: Alternaria alternata (Alternaria rot), Phlyctema vagabunda (bull's eye rot), and Penicillium expansum (blue mold) as the most frequent species isolated from symptomatic apples. Other pathogens found causing postharvest apple rots were Botrytis cinerea (gray mold), Diaporthe spp. (Diaporthe rot), and Colletotrichum fioriniae (bitter rot). Except for P. expansum, these fungi are recognized for causing latent infections in the orchard, which are not visible at harvest and cause postharvest decay only after long-term storage, typically 5-6 months. This has significant implications for management because our results indicate that a combination of orchard and postharvest practices are necessary to successfully manage the fungal pathogens identified. Multiple experiments were performed to study the fungicide sensitivity profile of Alternaria alternata, Phlyctema vagabunda, and Penicillium expansum, the most frequent postharvest apple pathogens identified during the packinghouse surveys of decayed apples. Multiple isolates of each species were tested in vitro and in vivo on artificially inoculated apples to compare their sensitivity profiles for fungicides commonly used in the Mid-Atlantic apple orchards and packinghouses. Isolates with reduced fungicide sensitivity were found for most combinations of pathogens and fungicides tested, which indicates that most fungicides currently used do not offer complete control of postharvest apple decay pathogens in the Mid-Atlantic. For P. expansum (blue mold), reduced sensitivity was observed in vitro for fludioxonil (FLU) and pyrimethanil (PYR), the fungicides currently used in the Mid-Atlantic apple packinghouses for blue mold management. However, on artificially inoculated apples, both fungicides offered good efficacy, which indicates that these fungicides are still viable alternatives against P. expansum. In addition to FLU and PYR, which are used only as postharvest fungicides, the following fungicides were also tested in vitro and in vivo on inoculated apples against A. alternata (Alternaria rot) and P. vagabunda (bull's eye rot): thiophanate-methyl (TM), difenoconazole (DIF), pyraclostrobin (PYRAC), trifloxystrobin (TFS), fluxapyroxad (FLUX), and fluopyram (FLP). These fungicides are currently used to manage multiple diseases in the Mid-Atlantic apple orchards, but information about their efficacy against A. alternata and P. vagabunda is not available. FLU was the only effective fungicide against A. alternata with 99% efficacy on inoculated apples, while other fungicides, including PYR, DIF, PYRAC, and TFS offered approximately 50% in vivo efficacy. These results show the limited options for A. alternata management in the Mid-Atlantic and the necessity for alternatives to synthetic fungicides. As observed for A. alternata, only a few fungicides were found effective against P. vagabunda, including FLUX, PYRAC, and TFS (79-83% in vivo efficacy). Objective 2. After establishing that spore-containing bin materials can incite blue mold disease, for this objective, we tested new treatments like UV-C irradiation, 2 % bleach solution, and 2-PE as bin sanitizer strategies to reduce blue mold inoculum levels. For this experiment, wood or plastic pieces were inoculated with spore suspensions and then applied the treatments individually (curative treatment). Spores were then collected, and recovery was recorded, viability of the recovered spores was tested, and infection potential was determined by measuring the lesion diameter on apples inoculated with suspensions of these same spores. While the recovery of spores varied among treatments and materials from 0 spores/mL to 1 X 105spores/mL, spore recovery for the 2% bleach treatment was significantly lower than the control treatment in both wood and plastic materials. Regarding spore viability, all the tested treatments were effective when applied as a curative treatment for plastic. For wood, only 2% bleach effectively reduced spore viability. When considering the effect of these treatments on the infection potential of apple fruit, we report a significant reduction for the 2% bleach treatment in both wood and plastic and 2-PE for plastic, which is congruent with the spore viability data. In addition to testing the effectiveness of novel sanitation treatments using a curative approach, we examined these using preventative applications and found that only the 2% bleach solution was effective in reducing spore viability in both wood and plastic materials. Furthermore, we expanded this dataset by testing the curative treatments in a Multi Drug Resistant (MDR) isolate finding similar results. Objective 3. The results of the experiments performed to identify the fungal species causing postharvest apple decay and to study their fungicide resistance profile were discussed with apple growers during the Mid-Atlantic Fruit & Vegetable Convention. Two oral presentations covered topics, such as identification of apple decay symptoms in the packinghouse, fungal species associated with postharvest decay in the Mid-Atlantic, and fungicide sensitivity and efficacy. The necessity to integrate orchard and postharvest management practices was emphasized, as well as the necessity to look for alternatives to synthetic fungicides. An extension article was published in the Pennsylvania Fruit News Journal (Vol. 104, pgs. 20-24) to discuss in more detail the fungicide sensitivity results found. An oral presentation and hands-on activities at the Adams & Franklin counties Winter Commercial Tree Fruit School (Spanish session) allowed discussion of orchard sanitation practices necessary to manage latent infections of fungi that cause postharvest apple decay. The hands-on activities, such as observation and description of tree infected tissues, complemented the concepts discussed during the oral presentation, and facilitated the audience engagement and discussion. Two packinghouses were visited in Adams and Bedford counties, PA to discuss a blue mold outbreak that affected the commercialization of apples for processing due to the presence of patulin, a regulated mycotoxin produced by blue mold fungi. The results obtained in this project (identification of blue mold fungi and their inoculum sources) were relevant to discuss with both growers the possible causes of this outbreak and recommend management practices to avoid similar outbreaks in the future.
Publications
- Type:
Other
Status:
Published
Year Published:
2024
Citation:
Castro, J. and Peter, K. A. 2024. Investigating fungicide sensitivity in postharvest apple decay fungi in the Mid-Atlantic. Pennsylvania Fruit News. 104: 20-24.
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Progress 09/01/22 to 08/31/23
Outputs
Target Audience:The target audiences reached during this reporting period include the 10 fruit packers/growers where the project research is occurring; applegrowers throughout the Mid-Atlantic (PA, MD, VA, NJ, Northeast); members of the LatinX community in Adams County, PA; Penn State Extension; agrochemical companies; andtree fruit researchers in academia, federal government, and private industry. In addition, we reached an international audience through our podcast and attendance at an international plant pathology conference. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training for Ph.D. student: Courses Food and Indoor Mycology and DNA-based identification of fungi, which occurred at the Westerdijk Fungal Biodiversity Institute, The Netherlands. October 3-5, 2022. This training allowed the student to expand the knowledge of morphological and DNA sequencing techniques used to identify fungi from inoculum sources and decayed apples. How have the results been disseminated to communities of interest?-Participation at the 2nd USDA Food Loss and Waste Innovation Fair (online). September 14, 2022. Topic: Reducing postharvest apple rots in the Mid-Atlantic. -Apple workshop, University of Maryland: Harvest and postharvest practices for improving fruit marketability: Fruit quality and safety. Poster and talk title: "Postharvest apple decay in the Mid-Atlantic: fungi lurking in storage and their effect on apple quality". November 7, 2022. - 2023 Mid-Atlantic Fruit and Vegetable Convention (January 31-February 2, 2023):Poster: "Bull's eye rot and Alternaria rot: Problem postharvest rots lurking in the Mid-Atlantic apple packinghouses". - Participation in theEuropean Fungal Genetics 16, Innsbruck, Austria, March 2023:poster presentation -Participation in the International Congress of Plant Pathology(ICPP), Lyon, France; August 2023:Poster title: "Location, Location, Location: The first rule of postharvest epidemiology for locating fungicide resistant blue mold fungi in commercial packinghouses." - Adams County Winter Tree Fruit School (February 20, 2023) - Spanish Session:Oral presentation in spanish: "La calidad postcosecha como un componente esencial en la producción de árboles frutales" ("Postharvest quality as an essential component of tree fruit production"). - Dr. Tree Fruit and Don Podcast (March 2023):"Postharvest Rot Series"of 4 episodes including Ph.D. student funded by this project, as well as co-PI Jurick and two of his postdocs. - Seminar at the University of Maryland, 2023: Plant Pathology and Microbiology Seminar about postharvest diseases - Article Pennsylvania Fruit News: Castro, J., Hartsock, J., Peter, K. 2023. Problem postharvest rots lurking: Investigating Alternaria rot and Bull's eye rot in PA and MD packinghouses. Pennsylvania Fruit News 103(1): 21-25. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, we will be wrapping up the analysis of fruit rot species and fungicide resistance profiles,evaluating different management controls (essential oils, bacterial-based products, chitosan) on prevention of postharvest rots and optimizing bin treatments. We will also be continuing to developbilingual resources (online, print, in-person) to stakeholders.
Impacts
What was accomplished under these goals?
Objective 1: Fungi causing postharvest apple decay and their inoculum sources: A second season of samplings was completed in 2022, confirming that the air of the packinghouses and cold rooms, and dump tank water are the main sources of Penicillium spp. (blue mold), according to data generated in this research, this represents approximately 14% of postharvest apple rots in the Mid-Atlantic. In addition to blue mold, Alternaria (Alternaria rot) and Phlyctema sp. (Bull's eye rot) accounted for 33% and 24%, respectively, of the rotten apples sampled throughout two seasons (2021 and 2022) (N = 975). Other genera found causing postharvest rots in the Mid-Atlantic were Botrytis, Diaporthe, Fusarium, and Colletotrichum. DNA sequencing of multiple genes and morphological characterization of representative isolates from inoculum sources and rotten apples was performed to determine the species. The most frequent Penicillium species isolated from inoculum sources were P. expansum, P. solitum, and P. brevicompactum, all of them previously reported as apple pathogens, with P. expansum as the main species causing postharvest apple decay globally. P. expansum was also the most frequent species found causing blue mold decay in the Mid-Atlantic, representing 91% of the isolates identified in this research (N = 67); although, as previously mentioned, this is not the most frequent postharvest apple disease found in the Mid-Atlantic. Phlyctema vagabunda was the species associated with bull's eye rot, and additional genes will be sequenced to complete the identification of the Alternaria spp. species, given the high genetic diversity of the genus. Other fungi causing postharvest rots and classified to species are Botrytis cinerea (gray mold) and Colletotrichum fioriniae (bitter rot). This study is the first extensive survey of fungi causing postharvest apple decay in the Mid-Atlantic and their inoculum sources. The results obtained so far have been discussed with apple growers during multiple scientific and extension activities, such as scientific meetings, podcasts, field days, and winter and spring tree fruit schools and twilight meetings. During these discussions, the outcomes of this project have been the foundation for postharvest apple decay management and mycotoxin abatement recommendations targeted to the Mid-Atlantic region. Fungicide resistance: A second season of samplings confirmed that the air of the packhouses and cold rooms are the main sources of Penicillium spp. fungicide resistant isolates. Three postharvest fungicides were tested, thiabendazole, fludioxonil, and pyrimethanil, and differences in the frequency of Penicillium spp. resistant isolates in the air of packinghouses and cold rooms were found between fungicides, with thiabendazole ranging from 44-89%, pyrimethanil (7-18%), and fludioxonil (8-30%). These results confirm the importance of cleaning and sanitation of postharvest facilities to eradicate fungicide resistant isolates and avoid fungicide failures. Fludioxonil and pyrimethanil, the fungicides used in the Mid-Atlantic for postharvest apple decay management, were selected to study the fungicide resistance profile of Altenaria spp., Phlyctema vagabunda, and Penicillium expansum, isolates obtained from decayed apples. Since Alternaria and Phlyctema are pathogens that usually infect apples before harvest and remain latent causing rots in postharvest, additional fungicides will be tested for these pathogens (fluxapyroxad, fluopyram, trifloxystrobin, pyraclostrobin, and thiophanate-methyl). These fungicides are the active ingredients recommended for pre-harvest applications in the Mid-Atlantic, particularly during the last cover sprays (2-8 weeks before harvest). Preliminary results indicate that isolates with reduced sensitivity to most of the fungicides tested are present in the Mid-Atlantic packinghouses. Therefore, alternative options to synthetic fungicides are necessary and will be tested for the management of postharvest apple decay, among them, the biological fungicides Serenade and Bio-Save, both bacterial formulations, with Bacillus subtilis and Pseudomonas syringae as active ingredients, respectively. Objective 2: Examining alternative treatments to reduce fungal inoculum on bin surfaces to reduce postharvest fruit decay:To identify and determine alternative treatments to reduce fungal inoculum on bin surfaces, we developed a small-scale assay to test different control treatments on both plastic and wood bin materials. For this, we point inoculate Penicillium expansum spores directly onto 4"X4" squares of each bin material (wood and plastic). After this, we let the spores dry and then apply the desired treatment (curative). We then recover the spores, count them, and assess their viability by plating and counting colony forming units (CFUs). To date, we have tested industry standard (2% bleach) and compared them to novel treatments including, (UV-C irradiation, 2-phenyl-ethanol (2-PE), and blue LED irradiation). Data shows that treatments with UV-C irradiation, 2-PE, and 2% bleach reduce inoculum viability significantly on plastic. While these results are promising, further assessments include the effect of pre-treatments (preventative) for bin materials along with a combination of the assessed methods to increase their efficacy. Also, we will test these methods for their ability to combat fungicide resistant isolates of Penicillium expansum. Objective 3:Data was presented in English and Spanishin oral talks and posters to stakeholders at the following: 2nd USDA Food Loss and Waste Innovation Fair (online). September 14, 2022. Topic: Reducing postharvest apple rots in the Mid-Atlantic. University of Costa Rica. Course: IB-0017 Propieades ingenieriles de los materiales biológicos "Engineering properties of biological materials". Talk title: "General concepts of fruit microbiology and management practices to reduce pre- and postharvest rots in apples". In Spanish. October 12, 2022 (via Zoom). Apple workshop, University of Maryland: Harvest and postharvest practices for improving fruit marketability: Fruit quality and safety. Poster and talk title: "Postharvest apple decay in the Mid-Atlantic: fungi lurking in storage and their effect on apple quality". November 7, 2022. Dr. Tree Fruit and Don podcast, Penn State Extension: "Postharvest rot series- Rot spores and where to find them." Recorded on March, 2023. Mid-Atlantic fruit and vegetable convention poster: "Bull's eye rot and Alternaria rot: Problem postharvest rots lurkingin the Mid-Atlantic apple packinghouses" (January 31-February 1, 2023). Adams County Winter Tree Fruit School (February 20, 2023). Oral presentation in Spanish: "La calidad postcosecha como un componente esencial en la producción de árboles frutales." 12th International Congress of Plant Pathology, Lyon, France. Poster: "Location, Location, Location: The first rule of postharvest epidemiology for locating fungicide resistant blue mold fungi in commercial packinghouses". August 20-25, 2023). Participation in theEuropean Fungal Genetics 16,Innsbruck, Austria, March 2023:poster presentation Seminar at the University of Maryland, 2023:Plant Pathology and Microbiology Seminar about postharvest diseases
Publications
- Type:
Other
Status:
Published
Year Published:
2023
Citation:
Castro, J., Hartsock, J., Peter, K. 2023. Problem postharvest rots lurking: Investigating Alternaria rot and Bulls eye rot in PA and MD packinghouses. Pennsylvania Fruit News 103(1): 21-25.
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
W.M. Jurick II, M-W. Choi, V.L. Gaskins, K.A. Peter, and K.D. Cox. 2022. Would You Like Wood or Plastic? Bin Material, Sanitation Treatments, and Bin Inoculum Levels Impact Blue Mold Decay of Stored Apple Fruit. Plant Disease. https://doi.org/10.1094/PDIS-05-22-1045-RE
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Progress 09/01/21 to 08/31/22
Outputs
Target Audience:The target audiences reached during this reporting period include 10 fruit packers/growers where the project research is occurring; fruit growers throughout the Mid-Atlantic (PA, MD, VA, NJ, Northeast); members of the LatinX community in Adams County, PA;and Penn State Extension. In addition, we reached an international audience through our podcast. Our efforts included meeting with the 10 fruit packer/growers about their operation and the results we found to date; one 30-minute presentationcovering postharvest diseases of apples and where fungal spores are orginating to cause disease, which was given and facilitatedby Penn State Extension at the Mid-Atlantic Fruit and Vegetable Convention in Hershey, PA on 2/1/2022 (there were approximately 200 participants); and a 90 minute presentation about postharvest diseases and management presented in Spanish at the Spanish Session held during the Annual Adams County Growers Winter Tree Fruit School in Biglerville, PA on 2/21/2022 (30 participants). We provided one episode devoted to postharvest apple diseases (200 plays). Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project is training one Ph.D. student (4th year) in the Department of Plant Pathology and Environmental Microbiology at Penn State University. In addition threestudents are assisting the Ph.D. student with collection and processing of samples for project. These students are being trained in macro- and microbiological, as well as molecular techniques to study and evaluate fungi. How have the results been disseminated to communities of interest?Preliminary results have been shared in a presentation about postharvest apple diseases in the 2022 Mid-Atlantic Fruit and Vegetable Convention in Hershey, PA, February 1-3, 2022. In addition, an episode was dedicated to postharvest apple diseases for the "Dr. Tree Fruit and Don" Podcast: Season 3, Episode 1 (January 27, 2022). Finally, a90 minute presentation about postharvest diseases and management presented in Spanish at the Spanish Session held during the Annual Adams County Growers Winter Tree Fruit School in Biglerville, PA (February 21, 2022). What do you plan to do during the next reporting period to accomplish the goals?We will continue with accomplishes the tasks described for Objective 1, which will include a second year of sampling orchards and packhouses as described for year 1. We will continue to identify to species the Penicillium isolates that have been phentypically grouped, as well as the species causing fruit rot on apples during storage. Fungicide resistant isolates will be testing on fungicide-treated apples to determine the type of resistance occurring for the recoverd isolates (practical vs. in vitro). In addition, we will continue to identify the different fungi causing76% of the rots occurring in storage.We will begin Objective 2, which is to determine and optimize alternative treatments and application methods to eliminate fungal inoculum on bins and fruit. ForObjective 3, we will be participating in educational opportunities for English and Spanish speakers about postharvest apple diseases. In addition, we will be participating in the 2nd USDA Food Loss and Waste Innovation Fair held virtually September 14, 2022 to share the research being conducted under this grant.
Impacts
What was accomplished under these goals?
Although the Mid-Atlantic fruit industry is a significant contributor to U.S. apple production (Pennsylvania ranks 4th), information is sparse for the Mid-Atlantic fruit industry when it comes to understanding causal fungal organisms for postharvest apple diseases and their sources, and appropriate mitigation measures. Based on previous research from the Northwest and New York blue mold, caused by Penicillium expansum, is the predominant postharvest apple rot occurring in storage.Region-specific research is greatly needed. It is unknown if blue mold is the most dominant fruit rot occurring in storage in the Mid-Atlantic. The practices to reduce blue mold are not routinely implemented in apple packinghouses located in the Mid-Atlantic region due to the economic cost and the lack of region-specific research demonstrating their efficacy on reducing the incidence and severity of postharvest apple rots. During this reporting period, our efforts have been focused on the first objective, which was to first understand the prevalence of blue mold spores occurring in the orchard and packhouse, if what is collected is resistant to common fungicides used for controlling blue mold, as well as identifying the most important apple rots coming out of storage (particularly, if blue mold is the most predominant fruit rot in Mid-Atlantic packhouses and, if not, what is the most predominant apple rot). By acquiring this knowledge, we can tailor appropriate, cost-effective mitigation measures for the Mid-Atlantic fruit industry. Specifically, we have been making progress on the following: Objective 1: Enumerate and identify inoculum sources and fungicide resistance profiles of fungi causing postharvest apple rots from the field through postharvest handling and storage. We began our sampling for 10orchards and their affiliated packhouses: 8 orchards/packhouses in Pennsylvania, 2 orchards/packhouses in Maryland. Orchard sampling occurred once for each orchard during late September through late October; packhouse sampling occured multiple times for each packhouse and started in October and continued through April 2022. To identify potential sources for blue mold spores: in the orchard, picking bags, fruit bins, and harvested fruit were sampled; in the packhouse: cold room air, packhouse facility air (non-cold room locations), and recently harvested fruit stored for less than one month, and fruit stored for 5-6 months. In addition, rotten fruit coming out of storage werealso collected during all packhouse sampling times. The blue mold isolates collected were also tested for fungicide resistance to commonly used postharvest fungicides: thiabendazole, pyriamthanil, fludioxonil, and difenconazole. In both Pennsylvania and Maryland orchards and packhouses, Penicillium spp. were frequently isolated in the air of the packhouse facilities and cold rooms, but not on the harvested fruit, and at a low frequency on bins and picking bags. Fungicide resistant isolates during year 1 of samplingwere obtained for thiabendazole, fludioxonil, and difenoconazole, ranging between 20% and 80% frequency in the air of the wet and dry areas of the packhouse, and between 10% and 90% in the air of cold rooms. Pyrimethanil was the only fungicide with no resistant isolates. The high frequency of Penicillium spp. resistant and non-resistant isolates in the air of the packhouse facilities and cold rooms suggests that those are critical points for fungicide resistance and potential for postharvest rots management, especially if we find a high incidence of apples coming out of storage with blue mold. We are in the process of identifying the causal Penicillium species for the blue mold isolates we have collected in all environments. We are also in the process of identifying the causal organisms of fruit rots coming out of storage. To date, we are identifying 14% of the apple rots coming out of storage are blue mold; the remaing 76% are rots caused by other fungi (currently being identified).We will also correlate if any apples with blue mold are infected with Penicillium spp. that are fungicide resistant to the previously mentioned fungicides.. Objective 2: Determine and optimize alternative treatments and application methods to eliminate fungal inoculum on bins and fruit. We have not started this objective. Work on this objective will begin Fall 2022 - Winter 2023. Objective 3: Develop and disseminate bilingual (English and Spanish) extension programs for optimized chemical and cultural postharvest disease management protocols and procedures. This project was introduced during an episode of the Dr. Tree Fruit and Don Podcast (English) during late January 2022. The Ph.D. student being funded by this grant provided a 30-minute presentation (English) about apple postharvest diseases and his preliminary results to-date at the 2022 Mid-Atlantic Fruit and Vegetable Convention in Hershey, PA, February 1-3, 2022. We provided a 90 minute presentation about postharvest diseases and management presented in Spanish at the Spanish Session held during the Annual Adams County Growers Winter Tree Fruit School in Biglerville, PA on February 21, 2022.
Publications
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