First report of Pantoea stewartii subsp. stewartii in Iran
The bacterial wilt of maize caused by Pantoea stewartii subsp. stewartii (EPPO A2 List) is first reported from Iran. Suspected symptoms on maize (Zea mays) plants were observed in fields in Iranshahr County (Sistan-Baluchestan Province, Southeastern Iran) in 2019. As Pantoea stewartii subsp. stewartii is a quarantine pest in Iran, a four-year comprehensive field survey and sampling program was initiated across maize growing areas in the country to monitor the occurrence and distribution of the disease. The survey covered 180 maize fields in 18 provinces and 51 counties. As a result, Stewart’s wilt disease was found in different geographic areas of Iran i.e. Bushehr, Fars, Hormozgan, Kermanshah, Khuzestan, Kohgiluyeh-Boyer Ahmad and Sistan-Baluchestan Provinces.
The authors note that Chaetocnema pulicaria, the primary vector of P. stewartii subsp. stewartii, does not occur in Iran, which suggests that spread into and within the country is probably associated with infected seed.
Sources
Alvandi H, Taghavi SM, Zarei S, Ansari M, Heidari M, Fazliarab A, Aeini M, Portier P, Osdaghi E (2025) Monitoring the occurrence and distribution of Stewart’s wilt of maize in Iran. Plant Disease (early view) https://doi.org/10.1094/PDIS-03-25-0509-SR