Global Theme: International Plant Diagnostic Network

Prompt and accurate diagnosis of plant diseases and detection of plant pathogens is crucial for integrated crop health management. This global program works toward this goal.


Prompt and accurate diagnosis of plant diseases and detection of plant pathogens is crucial for integrated crop health management. However, researchers, extension personnel and farmers in developing countries seldom have access to modern diagnostics. Global trade in seeds, vegetative planting material and fresh produce enhances the prospect for long-distance movement of plant pathogenic microorganisms. Modern diagnostic technology is critical to the interception of potentially devastating pathogens before they are exported worldwide.

Biotechnology-based diagnostic approaches combined with traditional microbiology and researcher training in these methods are needed, especially in export crop production areas. Techniques including polymerase chain reaction (PCR) assays and immunoassays have already been developed for several pathogens, including select agents, and can be used in developing country laboratories with appropriate equipment and technical training. These assays can be used to detect pathogens in plant material, insect vectors, water, air and soil, thus providing early identification of the causal agent and ability to initiate management or eradication procedures, depending on the pathogen and crop.

Program achievements and highlights

  • At Makerere University in Uganda, students and farmers were trained in diagnostic principles and techniques.
  • In Guatemala, a bacterial canker workshop was conducted in conjunction with USDA FAS, and train-the-trainer and farmer field days were held.
  • A program researcher identified the presence of two tomato pospiviroids in Ghana.
  • A program researcher published findings of the discovery of another tomato pospiviroid in Mali.
  • Four species of ash weevils were detected in vegetable crops in Tamil Nadu.

Phase IV official program title

The International Plant Diagnostic Network: Gateway to IPM Implementation and Enhanced Trade


Principal Investigator

Sally Miller, Professor of Plant Pathology, The Ohio State University

Co-PIs/Host-Country Collaborations

United StatesRobert Gilbertson, UC-Davis | Timur Momol, Carrie Harmon, and J. Xin, University of Florida

Guatemala: Marco Arevalo, Agroexpertos

India: S. Mohankumar and G. Karthikeyan, Tamil Nadu Agricultural University

Kenya: Zachary Kinyua, Kenya Agricultural Research Institute

Nigeria: R. Banyopadhyay and Lava Kumar, IITA

Tanzania: Fen Beed, IITA

Uganda: Mildred Ochowo-Ssemakula, Makerere University