Fungal leaf spots: field, lab, and online tutorial for professionals in Guam and the Northern Mariana Islands

Project Overview

Project Type: Professional Development Program
Funds awarded in 2020: $66,013.00
Projected End Date: 08/31/2022
Host Institution Award ID: G128-21-W7903
Grant Recipients: University of Guam; University of Georgia
Region: Western
State: Guam
Principal Investigator:
Dr. Robert Schlub
University of Guam
Dr. Marin Brewer
University of Georgia
Dr. Robert Kemerait
University of Georgia
Dr. Kisha Shelton
University of Georgia
Dr. Leilan Sumabat-Dacones
University of Philippines

Information Products


Not commodity specific


  • Crop Production: Plant disease identification
  • Education and Training: demonstration, display, workshop
  • Pest Management: field monitoring/scouting, integrated pest management, prevention, sanitation

    Proposal abstract:

    The cornerstone of a sustainable plant disease control program for any farm community hinges on well-trained agricultural professionals. Diagnosing diseases in Guam and the Northern Mariana Islands is a constant challenge because of the yearly movement of nearly 2 million tourists and the importation of large quantities of fresh produce. Compounding the problem is the islands’ remoteness from mainstream plant pathology research and teaching facilities. Project’s long-term goals are to increase economic viability and enhance environmental quality of small commercial and subsistence farming operations in the region through accurate and timely diagnoses of plant diseases. The project’s immediate goal is to provide agricultural professionals with the skills and knowledge useful in discerning leaf spots caused by fungi as opposed to those caused by bacteria or chemical sprays.  Trainees will be provided with the skills necessary to differentiate among similar and often confused symptoms caused by three common and virulent fungal genera: Colletotrichum, Cercospora, and Corynespora. Using trainers from Georgia and the Philippines, will bring a national and  an international perspective to the workshop. Travel cost for the trainers will be kept to a minimum by scheduling the workshop to coincide with their other travel plans. Activities include: 1) Guam assembling workshop materials; 2) Guam collecting images of field symptoms and micrographs of spores from 15 foliar fungi including Colletotrichum, Cercospora, and Corynespora; 3) Guam preparing single spore isolates; 4) Georgia identifying isolates and depositing sequences to GenBank; 5) Guam updating Guam’s Index of Plant Diseases; 6) Guam, Georgia and Philippines conducting a four-day plant disease diagnostic workshop for 12 trainees composed of field trips, lectures, hands-on examination of samples, laboratory exercises, and engagement opportunities with the local farmers and the public; and 7) Guam, Georgia and Philippines posting identification tutorial online; and 8) Georgia and Guam conducting a workshop evaluation.

    Project objectives from proposal:

    Objective 1) Increase the technical capacity of the University of Guam to train agricultural professionals about foliar fungal leaf spots through the assembly and development of training materials.

    Objective 2) Increase diagnostic collaboration between the Universities of Guam, Georgia, and the Philippines by identifying unknown species of Colletotrichum, Cercospora, and Corynespora and other fungal leaf spots that occur on Guam and enter such information into the Guam Index of Plant Diseases and other databases.

    Objective 3) Increase the skills of agricultural professionals in Guam and the Northern Mariana Islands to diagnose fungal leaf spots and to be able to pass this information on to their constituents, through the production of a diagnostic workshop composed of field trips, lectures, and microscopic examination of plant samples.

    Objective 4) Use workshop evaluations consisting of surveys and pre and post-tests to measure knowledge gained and identify opportunities for future plant pathology related activities and the means through which delivery of diagnostic skills and knowledge to trainees or stakeholders in future workshops can be improved.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.