Update on the situation of Pantoea stewartii subsp. stewartii in Italy
In Italy, the bacterial wilt of maize caused by Pantoea stewartii subsp. stewartii (EPPO A2 List) had been found in several regions but was subsequently eradicated (EPPO RS 2020/130, RS 2021/201, RS 2022/065). The pathogen was found again in 2022 during official surveys of maize (Zea mays) grown for seed in Emilia-Romagna region. At least 10% of the seed crops (5967 ha) were inspected. In 2022, 16 samples with suspect symptoms were taken and tested according to EPPO diagnostic protocol PM 7/60. Seven samples tested positive, they came from fields located in the municipality of Castel Guelfo di Bologna and Medicina (both Bologna province). The plants within 1.5 m radius around the infected maize plants were uprooted and destroyed. Before harvesting, at 30% seed humidity, maize cobs will be collected in the affected area and tested to verify the absence of the pathogen before marketing the seed.
The pest status of Pantoea stewartii subsp. stewartii in Italy is officially declared as: Transient, actionable, under eradication.
Sources
NPPO of Italy (2022-06).