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ISTA Reference Pest List - version 6 (2020-07)


A list of seed-borne and seed transmitted pathogens associated with seed of Barley, Cotton, Oat, Sorghum, Soybean, Sunflower, Rapeseed, Rice, Triticale and Wheat. 

Check the website for the description of the list https://www.seedtest.org/en/ista-reference-pest-list-_content---1--3477.html


As defined in the International Standard for Phytosanitary Measures issue on the international movement of seeds (ISPM38):
(i) a seed-borne pest is carried by seeds externally or internally that may or may not be transmitted to plants growing from the seeds, causing their infestation.
(ii) a seed-transmitted pest is a seed-borne pest that is transmitted via seeds directly to plants growing from these seeds, causing their infestation.
(iii) seed can be a pathway for the introduction and dissemination of pests in a new geographic area through seed trade.

As defined in the International Standard for Phytosanitary Measures issue on Glossary of phytosanitary terms (ISPM5):
(iv) a pest is defined as any species, strain or biotype of plant, animal or pathogenic agent injurious to plants or plant products.

Organisms included in the lists

- The ISTA Reference Pest List includes bacteria, fungi, oomycetes, virus and nematodes pathogenic to seed crops.
- Pests without a scientific evidence that they are seed-borne are not included in the ISTA Reference Pest List. They could be included once evidence will be proven.
- Some saprotrophs are also included when scientific literature illustrates their seed-borne status, but for those organisms, the final decision about seed as a pathway of dissemination is not applicable (N/A), as they do not induce diseases.
- In case of emerging pests, they could be included in the lists as soon as they are suespected to be at risk for seed trade, even if their seed-borne, and eventually seed-transmitted status is fully stated. In these cases, literature survey will be conducted to share the most up-to-date knowledge and it will be indicated in the lists (pest categorization under investigation).


  • Avena sativa
  • Brassica napus
  • Glycine max
  • Gossypium
  • Helianthus annuus
  • Hordeum vulgare
  • Oryza sativa
  • Sorghum
  • Triticum
  • x Triticosecale


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