Update on the situation of Pantoea stewartii in Italy
The NPPO of Italy recently informed the EPPO Secretariat of the detection of Pantoea stewartii (EPPO A2 List) on maize (Zea mays) crops in the regions of Emilia-Romagna and Lombardia. The NPPO recalled that the last records of the bacterium had been made in 2016 in Emilia-Romagna, and in 2017 in Friuli Venezia Giulia (EPPO RS 2018/038) and Veneto. In all cases, eradication measures were taken.
Emilia-Romagna: In May 2018, symptoms resembling those of P. stewartii were observed during official inspections in 2 farms in the province of Bologna in maize seed crops (hybrid maize). Affected plants showed long leaf chlorotic streaks with irregular margins and vascular browning. Symptomatic samples were collected, and molecular tests confirmed the presence of the bacterium. The origin of this outbreak is unknown, but it is suspected that imports of infected parental lines might be a source. The NPPO noted that it is now required that seed companies should test parental lines before sowing.
Lombardia: In July 2018, symptoms resembling those of P. stewartii were observed during official inspections in 2 farms in the province of Cremona in maize seed crops. Symptomatic samples were collected, and molecular tests confirmed the presence of the bacterium. The number of infected plants was very low, and no crop losses were observed. The maize harvest will be used for animal feed rather than seed production as had been initially planned.
The pest status of Pantoea stewartii in Italy is officially declared as: Present, in specific parts of the Member State, where host crop(s) are grown, under eradication.
Sources
NPPO of Italy (2018-08, 2018-09).