Two new diagnostic protocols adopted to strengthen plant pest detection

Rome, 27 August 2025. Two new diagnostic protocols (DP) have been adopted under the International Plant Protection Convention (IPPC) to support countries in accurately detecting and identifying harmful plant pests to enhance controls and management strategies. Following the IPPC procedure, the Standards Committee (SC) adopted these two new DPs on behalf of the Commission on Phytosanitary Measures (CPM) after the August DP notification period.

The newly adopted protocols are DP 35: Meloidogyne mali (2018-019), which addresses the root-knot nematode affecting fruit trees and a range of other crops, and DP 36: Pospiviroid species (2018-031), which covers a group of viroids that can cause serious diseases in solanaceous crops such as tomato and potato, as well as in ornamentals and citrus.

Accurate diagnosis is the first and one of the most critical steps in protecting plant health. The early and reliable identification of pests allows countries to act swiftly to prevent their introduction and spread, safeguarding food security, protecting biodiversity, and supporting safe trade.

Diagnostic Protocols are annexes to ISPM 27 (Diagnostic Protocols for Regulated Pests), one of the International Standards for Phytosanitary Measures (ISPMs). They provide harmonized minimum requirements for accurate pest diagnosis and internationally recognized procedures for laboratories and plant health authorities worldwide, ensuring that diagnostic results are consistent and scientifically sound.

Global impact on crops and regions

Meloidogyne mali has been widely reported in certain countries in Asia region and detected with restricted distribution in Europe, Asia and North America. Its principal hosts include apple (Malus domestica), elm (Ulmus) and mulberry (Morus), though it can also affect other fruit trees, shrubs, and vegetables. It has been reported that in one single country in Asia, infestations by this nematode have reduced apple tree growth by 15–43 percent and significantly lowered fruit yields, while mulberry trials recorded up to 50 percent crop loss.

Pospiviroid species, meanwhile, are globally distributed and can infect a wide range of plants. Tomatoes and potatoes are the most economically significant hosts, where infections can stunt growth, reduce fruit size, or cause spindle-shaped tubers. In addition, peppers, citrus, chrysanthemums, and other ornamentals are also natural hosts, highlighting the wide-ranging risks these pathogens pose. Pospiviroids spread easily via contaminated seeds, propagation material, mechanical tools, pollen, and in some cases insect vectors, making accurate and rapid diagnosis essential.

“Adopting these new diagnostic protocols strengthens the toolbox available to national plant protection organizations,” said Avetik Nersisyan, IPPC Officer-in-Charge for day-to-day matters and Lead of the Standard Setting Unit (SSU). “With harmonized diagnostic methods, countries are better equipped to take science-based decisions, anticipate and respond to outbreaks, and build confidence in international trade.”

The protocols were developed by the IPPC Technical Panel on Diagnostic Protocols, a group of global experts who regularly review and update diagnostic methods to reflect the latest scientific advances. With these two new DPs, the portfolio of adopted diagnostic protocols now expands to 36 Diagnostic Protocols officially adopted under ISPM 27, reinforcing global collaboration in the fight against plant pests.

"By providing our global community with harmonized, science-based tools for diagnosis, we are building a more resilient and proactive phytosanitary system”, said Adriana Moreira, SSU Deputy Lead. For more information about the adopted DPs please refer to:

• https://www.ippc.int/en/core-activities/standards-setting/ispms/
• https://www.ippc.int/en/core-activities/standards-setting/notification-period-dps/

#PlantHealth #IPPC #DiagnosticProtocols #ISPM27