Progress 11/22/16 to 09/30/21
Outputs
Target Audience:The target audience of the project includes the public, cucumber growers, and the scientific community of the American Phytopathological Society. Delivery will be accomplished through the University of Guam Cooperative Extension and Outreach website (www.uog.edu/extension), Pacific Daily News, annual meeting the American Phytopathological Society, and the archives of the American Phytopathological Society. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?As a result of a strategic planning workshop conducted by Guam extension agents, growers were trained in IPM practices that could be used to reduce the impact of the disease anthracnose in their cucumber plots. The knowledge gained from the statistical analysis of the cultivar inoculation trial provided agricultural professionals with new information which was valuable in advisement of growers. How have the results been disseminated to communities of interest?By way of extension agent farm visits, cucumber growers became aware of the results of the variety trail and used this information as part of their cultivar selection process.As a result of an article in the Pacific Daily News, the citizenry of Guam grained some basic knowledge about cucumber anthracnose and how to reduce its impact through the application of IPM practices. https://www.guampdn.com/lifestyle/home-garden-tips-combating-anthracnose-of-cucumber/article_d5544aeb-e62f-5479-80e0-6a2a1e38270c.html A three -hour workshop covering all aspects of growing cucumbers under the pressures of anthracnose was presented to eleven UOG agriculture students. Students learned about how the variety trail was conducted, how it was analyzed, and what the findings were. Results were disseminated to the scientific community through a poster presented at the annual meeting of the American Phytopathological Societyhttps://www.apsnet.org/meetings/annual/meetingarchives/planthealth2019/Documents/Abstracts/aps2019ab207.htm). For the university community, theposter was placed on the University of Guam Cooperative Extension and Outreach website (https://www.uog.edu/_resources/files/extension/Screening_Commercial_Cucumber_Cultivars.pdf). What do you plan to do during the next reporting period to accomplish the goals?The project ended.
Impacts
What was accomplished under these goals?
Objective1:Selection of cucumber test cultivars for evaluation. During year one of the proposal, as a result of strategic planning between Guam's major cucumber growers and Guam extension agents, growers and agents were able to evaluate Guam farm practices and identify means by which losses from cucumber anthracnose could be reduced and profits increased. In addition, the attendees selected twenty-two cucumber cultivars for trials to determine resistance to anthracnose. Varieties selected included some old Guam standard varieties and new ones that had ever been grown on Guam. Objective2: Isolation and confirmation of Colletotrichum species responsible for cucumber anthracnose disease on Guam. During year two of the proposal, cucumber leaves containing lesions symptomatic of anthracnose were collected from a local farm. From these lesions, spores cultures believed to be Colletotrichum sp, were obtained. These cultures were sent to Dr. Cheryl Blomquist, Senior Plant Pathologist at the CDFA- Plant Pest Diagnostics Center in Sacramento California for identification of pathogen species. Dr. Blomquist confirmed the identity of the anthracnose species to be C. orbiculare. Proper identification of the C. orbiculare species responsible for cucumber anthracnose disease in Guam will save growers money by allowing them to search the worldwide web for cucumber varieties that have resistance or tolerance to Guam's specific pathogen. Objective3:Screening cucumber cultivars for resistance of the fungal disease anthracnose. During year two of the proposal, data was collected from 22 cucumber cultivar trials. Four replications of each cultivar were evaluated for resistance against anthracnose based on size and number of lesions after being spray inoculated with C. orbiculare. All results for the 88 samples were compiled into Microsoft Excel and forwarded to the PI and statistician for evaluation. This was the first trial of its kind on Guam and set the stage for improved cucumber production on Guam by providing cucumber growers the information they need for selecting varieties. Objective4:Rank cucumber cultivars for anthracnose resistance and relay information to the scientific community, Guam's producers and citizenry. During years three and four of the proposal, as a result of statistical analysis using One-Way ANOVA of the cucumber cultivar inoculation data, those varieties offering the most and least resistance to Guam's cucumber anthracnose pathogen were identified. The four varieties identified were Poinsett 76, Olympian, Tasty King and Sinews. Poinsett 76 and Olympian were found to be resistant, while Tasty King and Sinews were shown to be susceptible to the disease. The variety trial results were presented at a Cucumber Anthracnose Workshop at the University of Guam hosted on February 13, 2019. There were eleven UOG students in attendance; farmers were invited but none were able to attend the workshop. By way of extension agent farm visits, cucumber growers became aware of the results of the variety trial and used this information as part of their cultivar selection process. Objective5:Collect suspected fungal pathogen Corynespora cassiicola from leaf spots of various hosts, isolate single spores onto media, and send to the University of Georgia for identification to species. During year four of the proposal, as a result of the evaluation and submission of Guam's Corynespora cassiicola isolates to Dr. Marin Brewer at the University of Georgia, important isolates used in the research of Dr. Linley Dixon and Dr. Robert Schlub were preserved in major collections and made available for other researchers worldwide. Thirty-nine samples from twenty-three different hosts were selected for storage at the University of Georgia. Cultures were stored at the University of Georgia in glycerol at -80°C and on filter papers at -20°C. During year five of the proposal, isolates selected and agreed upon by Dr. Robert L. Schlub and Dr. Marin Brewer were retrieved from storage and shipped to the Westerdijk Institute. A total of 25 of Guam's Corynespora isolates were accepted by the Westerdijk Fungal Biodiversity Institute.
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Progress 10/01/19 to 09/30/20
Outputs
Target Audience:Farmers, home gardeners, scientists, extension agents, and agriculture professionals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training and professional development were not part of the proposal. How have the results been disseminated to communities of interest?Updates will be made to the Guam plant disease database which is on the University of Guam website. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact According to the "Eggplant, Pepper, and Tomato Production Guide for Guam" the fungus Coynespora cassiicola is a serious plant pathogen on Guam. It causes production loss in not only solanaceous crops but also in papaya and ornamentals.The conidia (spores) of C. cassiicola closely resembles other fungal conidia like Cercospora, Bipolaris, Helminthosporium and others. In order to insure a pathogen is C. cassiicola it must be identified by an expert. During this reporting period, samples were collected of suspected fungal pathogen Coynespora cassiicola from leaf spots of various hosts, isolated onto media, and sent to the University of Georgia for identification to species. Thirty-nine samples from 23 different hosts were identified as C. cassiicola. The Guam plant disease database will be updated and Georgia will use the samples for research purposes. Note: This report is for year four of a five-year proposal. Objectives Obj. 1: Selection of cucumber test cultivars for evaluation. This objective was accomplished during year one of the five-year proposal (see year one annual report). Obj. 2: Isolation and confirmation of Colletotrichum species responsible for cucumber anthracnose disease on Guam. This objective was accomplished during year two of the five-year proposal (see year two annual report). Obj. 3: Screening cucumber cultivars for resistance of the fungal disease anthracnose. This objective was accomplished during year two of the five-year proposal (see year two annual report). .Obj. 4: Rank cucumber cultivars for anthracnose resistance and relay information to the scientific community, Guam's producers and citizenry. This objective was accomplished during year three of the five-year proposal (see year three annual report). Obj. 5 (New/added objective): Collect suspected fungal pathogen Coynespora cassiicola from leaf spots of various hosts, isolate single spores onto media, and send to the University of Georgia for identification to species. Suspected Coynespora cassiicola were collected from the leaves of over 30 different hosts on Guam. C. cassiicola conidia from the leaf spots of the host plants were then streaked onto water agar. A single conidia from the water agar was then isolated into glass vials containing V8 medium. The vials were shipped to a Mycologist doing research on C. cassiicola at the University of Georgia for identification to species. At Georgia, it was discovered that some of the samples were contaminated with Penicillium sp. orFusarium sp. like fungi. These samples were discarded. For the non-contaminated samples, two plugs from each vial were plated onto two separate PDA media plates. After growout, the samples were confirmedas C. cassiicola based on both culture and spore morphology. The confirmed sample list follows: 1 Lantana camara 2 Spathodea campanulata 3 Hibiscus sp. 4 Asysatia sp. 5 Desmodium sp. 6 Kalanchoe thyrsiflora 7 Tournefortia argentea 8 Anona sp. 9 Passiflora foetida 10 Moringa oleifera 11 Mutingia calabura 12 Elephantopus sp. 13 Acanthaceae 14 Telosma cordata 15 Premna sp. 16 Waltheria indica 17 Cassia sp. 18 Bauhinia sp. 19 Vitex parviflora 20 Waltheria indica 21 Macroptillium atroput 22 Macroptillium atroput 23 Ficus benjamani 24 Carica papaya 25 Carica papaya 26 Carica papaya 27 Carica papaya 28 Solanum lycopersicum 29 Solanum lycopersicum 30 Solanum lycopersicum 31 Solanum lycopersicum 32 Solanum lycopersicum 33 Solanum lycopersicum 34 Solanum lycopersicum 35 Solanum lycopersicum 36 Solanum lycopersicum 37 Solanum lycopersicum 38 Solanum lycopersicum 39 Solanum lycopersicum This information will be added to the Guam plant disease database. Cultures will be stored at the University of Georgia in glycerol at -80C and on filter papers at -20C for use in future research.
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Progress 10/01/18 to 09/30/19
Outputs
Target Audience:Farmers, home gardeners, scientists, extension agents, and agriculture professionals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training and professional development were not part of the proposal. How have the results been disseminated to communities of interest?Results were desseminated during the third year in a local workshop, a poster placed on the University of Guam website, and a poster presentated at the annual American Phytopathological Society meeting. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact According to the Guam Cucurbit Guide the disease anthracnose of cucumber is common and of high importance for cucumber production in Guam. Colletotrichum orbiculare, the fungus that causes anthracnose, has been known to occur since 1867 in the United States and 1979 in Guam. Yield losses caused by anthracnose range from as low as 2% for large-scale commercial producers to as high as 50% for small field plots under high disease pressure. Based on a yield loss value of 15%, the loss in revenue to Guam's growers from anthracnose is estimated to be $178,000 based on 1,332,000 lbs. of production and a market value of $890,775. As a first step in managing this disease, it is proposed that resistant cultivars be identified through a seedling inoculation trial. Advantages of using seedling inoculation over nature field screening include less space, less labor and less experimental error. Reduction of experimental error is due to the fact that there is no error generated due to differences between and among fields, to pathogen levels, to soil nutrients levels, to soil structure and to weed pressures. The results were made available through a poster placed on the University of Guam Cooperative Extension and Outreach website (https://cnas-re.uog.edu/wp-content/uploads/2019/11/Poster_Screening-Commercial-Cucumber-Cultivars-for-Resistance-To-Anthracnose-Using-Image-Analysis_Schlub-2019.pdf). This poster was also presented at the annual American Phytopathological Society meeting. In addition, a half-day workshop was held on the variety trial results for growers and the public. Funding of this proposal will support current and future IPM research and extension activities of Dr. Robert Schlub through the NIFA CPPM-EIP program. Note: This report is for year three of a five-year proposal. Obj. 1: Selection of cucumber test cultivars for evaluation. This objective was accomplished during year one of the five-year proposal (see year one annual report). Obj. 2:Isolation and confirmation of Colletotrichum species responsible for cucumber anthracnose disease on Guam. This objective were accomplished during year two of the five-year proposal (see year two annual report). Obj. 3: Screening cucumber cultivars for resistance of the fungal disease anthracnose. This objective were accomplished during year two of the five-year proposal (see year two annual report). .Obj. 4:Rank cucumber cultivars for anthracnose resistance and relay information to the scientific community, Guam's producers and citizenry. The variety trial results were presented at a Cucumber Anthracnose Workshop at the University of Guam. There were eleven participants in attendance. A pre-test was distributed prior to the presentation and a post-test was distributed afterward. The smallest percentage change from pre-test to post-test was a gain of 18%. The greatest percent change from pre-test to post-test was a gain of 72%; two individuals showed this increase. Based on the workshop "Program Evaluation" sheet, attendees felt that the presenter was well prepared and knowledgeable on the topic. The results were made available through a poster placed on the University of Guam Cooperative Extension and Outreach website (https://cnas-re.uog.edu/wp-content/uploads/2019/11/Poster_Screening-Commercial-Cucumber-Cultivars-for-Resistance-To-Anthracnose-Using-Image-Analysis_Schlub-2019.pdf). This poster was also presented at the annual American Phytopathological Society meeting.
Publications
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Progress 10/01/17 to 09/30/18
Outputs
Target Audience:Farmers, home gardeners, scientists, extension agents, and agriculture professionals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training and professional development were not part of the proposal. How have the results been disseminated to communities of interest?Results will be desseminated during the third year through a local workshop and a poster presentation at the annualAmerican Phytopathological Society meeting. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact According to the Guam Cucurbit Guide the disease cucumber anthracnose is common and of high importance to cucumber production profitability in Guam. Cucumber anthracnose has been known to occur since 1867 in the United States and 1979 in Guam. Yield losses due to anthracnose can range from as low as 2% for large-scale commercial producers to as high as 50% for small field plots under high disease pressure. Based on a yield loss value of 15%, the loss in revenue to Guam's growers from anthracnose in a single year is estimated to be $178,000 based on 1,332,000 lbs. of production at a market value of $890,775. During this reporting period, cucumber candidates for anthracnose screening were identified along with the determination of species of Colletotrichum responsible for cucumber anthracnose on Guam. Dr. Cheryl Blomquist, Senior Plant Pathologist at the CDFA- Plant Pest Diagnostics Center in Sacramento California identified the casual agent of Guam's cucumber anthracnose to be Colletotrichum orbiculare. Four replications of 22 cucumber cultivars were evaluated for resistance against anthracnose based on size and number of lesions after inoculation with C. orbiculare. A data collection of 88 observations was sent to Dr. Brian Marx at the Louisiana State University for statistical analysis. Note: This report is for year two of a three-year proposal. Obj. 1: Selection of cucumber test cultivars for evaluation. This objective was completed in year one. Refer to year one report for details. Obj. 2: Isolation and confirmation of Colletotrichum species responsible for cucumber anthracnose disease in Guam Cucumber leaves containing lesions symptomatic of anthracnose were collected from a local farm. From these lesions, spores believed to be Colletotrichum sp, were streaked onto plates of PDA agar + chloramphenicol. At a later date, single spore cultures were obtained. On November 15, 2017, slants of Colletotrichum sp. were sent to Dr. Cheryl Blomquist, Senior Plant Pathologist at the CDFA- Plant Pest Diagnostics Center in Sacramento California, for identification of pathogen species. On December 22, 2017, Dr. Blomquist confirmed the identity of the anthracnose species to be C. orbiculare, with sequences resulting in a 100% match to the C. orbiculare type strainCBS 570.97=LARS 73(Damm et al. Fungal Diversity, 2013). Obj. 3: Screening cucumber cultivars for resistance to the fungal disease anthracnose. Four replications of 22 cucumber cultivars were evaluated for resistance against anthracnose based on size and number of lesions after spray inoculated with C. orbiculare. Lesion size and numbers were determined by image analysis of leaf scans. Adobe Photoshop software, ImageJ, and Microsoft Excel were used during this process. The images were then labeled and sorted into digital files. After a series of trials, due to the severity spectrum of infection, it was decided to evaluate the leaves according to Thompson and Jenkins 1985 Visual Rating Scale (VR). The VR scale ranged from 1 (leaf is predominantly healthy with no visible signs of infection) to 8 (75-100% of the leaf surface with lesions). Total leaf area and percent area diseased were then measured using ImageJ software. Two images were made of each leaf. One was a photo scan and the other was a photo shopped image containing an ascribed circle (AC). Using ImageJ software the area within AC was analyzed. This allowed for a manageable and accurate representation of the number of lesions per leaf even if severely diseased. All the results for the 88 samples were compiled into Microsoft Excel for review by the PI and statistician. Obj. 4: Rank cucumber cultivars for anthracnose resistance and relay information to the scientific community, Guam's producers and citizenry. This objective has three major activities. Two of these activities were completed in year two and will be included in this report. These activities include designing and execution of the cucumber cultivar anthracnose experiment and data analyze. Five replications were made of each cultivar. Four were inoculated and one left non-inoculated (control). Plants were grown in a partial shade area. When the majority of the cultivars had reached the fourth leaf stage, which was approximately 15 days after planting, the plants were inoculated. Leaves with anthracnose lesions were obtained from John Mesa's farm and placed in a moisture chamber for 24 hours for further growth. The next day, lesions were cut into small pieces and placed in 5 ml of water and vortexed. Spores were counted with a Hausser Bright-line metallized hemacytometer under a compound microscope. Spore concentration was adjusted to 10,000 ml. Plants were spray inoculated to point of runoff and placed under a plastic tent at 100% RH for 24 hrs. Five days after inoculation, the third leaf of each plant was removed and pressed for preservation. Pressing inhibited further progression of fungal growth and preserved the samples for image analysis. Statistical analysis using One-Way ANOVA was applied to the cultivar inoculation data. After preliminary analysis of a small data set and the rejection of some dependent variables, the final analysis consisted of one independent variable (cultivars) and four dependent variables VR (visual rating scale), TLArea (total leaf area), PerDiseased (Percent area diseased in ascribed circle, and NoLesionC (Number of lesions per cm2, in the ascribed circle). Tukey's studentized range (HSD) Test was <0.001 for all dependent variables. Contrast testing of Resistance Vs Susceptible revealed the following significant pairs: 26 among 231 for VR, 7 among 231 for PerDisease, and 19 among 231 for NoLesionsC. When weights were given to repeated cultivar groupings of t-test (LSD) results across VR, PerDisease, NoLesionC the follow cultivars were identified as the most resistant to anthracnose: Summer top, Olympia (trd), Olympia, Blessing, Poinsett76, Soarer, and TI-09E. Those identified as the most susceptible included Early Triumph, Tasty King, and Turbo.
Publications
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Progress 11/22/16 to 09/30/17
Outputs
Target Audience:Farmers, home gardeners, scientists, extension agents, and agriculture professionals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training and profressional development is not part of this year's objective. How have the results been disseminated to communities of interest?Results will be disseminated during the third year of the project. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impacts According to the Guam Cucurbit Guide the disease anthracnose of cucumber is common and of high importance to cucumber production profitability in Guam. Colletotrichum orbiculare, the fungus that causes anthracnose, has been known to occur since 1867 in the United States and 1979 in Guam. Yield losses due to anthracnose range from as low as 2% for large-scale commercial producers to as high as 50% for small field plots under high disease pressure. Based on a yield loss value of 15%, the loss in revenue to Guam's growers from anthracnose is estimated to be $178,000 based on 1,332,000 lbs. of production and a market value of $890,775. During this reporting period, selection of cucumber cultivars and purchasing of seed for evaluation were completed. The opinion of University of Guam Extension Agents and 5 major Guam cucumber growers were solicitedregarding cucumber cultivars forinclusion in theseedling screening trial. Selection was also made based on reviewing seed company literature information such ascost of seed,availability of seed, anthracnose resistance, fruit type, and high temperature hardiness. Twenty-two cultivars were selected for an anthracnose resistance experiment which will be conducted during the second year of this project. Note: This report is for year one of a three year proposal. Obj. 1: Selection of cucumber test cultivars for evaluation. Twenty-two cultivars were selected for evaluation. The opinion of University of Guam Extension Agents and 5 major Guam cucumber growers were solicitedregarding cucumber cultivars forinclusion in theseedling screening trial. Selection was also made based on reviewing seed company literature information such ascost of seed,availability of seed, anthracnose resistance, fruit type, and high temperature hardiness. The cultivars that were chosen for evaluation are: -Johnny's Selected Seeds : Olympian F1; Olympian F1 (treated); SV4719CS F1. -Kitazawa Seed Company: Summer Top; Soarer; TI-09E. -Reimer Seeds: Dasher II; Early Triumph; Eureka; Fanfare; Marketmore 76; Poinsett 78; Rockingham; Speedway; Stonewall; Tasty King; Thunder; Turbo. -KNOWN-YOU Seed Company: Richmond; Fountain; Sinews; Blessing. All seeds have been purchased and received. Seeds were purchased online with the exception of cultivars from KNOWN-YOU Seed Company. These were purchased from a local vendor. Obj. 2: Isolation and confirmation ofColletotrichumspecies responsible for cucumber anthracnose disease in Guam. This objective will be accomplished during the second year of the proposal. Obj. 3: Screening cucumber cultivars for resistance to the fungal disease anthracnose. This objective will be accomplished during the second year of the proposal. Obj. 4: Rank cucumber cultivars for anthracnose resistance and relay information to the scientific community, Guam's producers and citizenry. This objective will be accomplished during the third year of the proposal.
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