Occurrence of Phytolacca americana in crop fields in the EPPO region
Phytolacca americana is native to North America and widespread in the EPPO region. Within the EPPO region, the species occurs in clear-cut areas, along hedgerows and wasteland, along field margins, canals and coastal areas. The species is found in forest plantations and in disturbed woodlands. In 2021, infestations of P. americana were surveyed in Southern Austria and included the municipalities of Gabersdorf and St. Veit am Vogau. The results of the survey showed that P. americana colonized mainly the narrow strip between two crop fields and field margins, but it sometimes also occurred inside the crop field. The species infested predominately oil pumpkin and maize (comprising of > 90% of all records in crop fields), but also soybean and cereal crops. In this area, P. americana was frequently observed in the interspersed wooded areas, as well as in ruderal habitats (e.g. roadsides, wasteland), below power pylons and tree stands. Population sizes in these habitats ranged from a few (large) individuals to more than 100. The authors consider that P. americana will not become a significant invasive alien plant in Austria, but under certain conditions the species can be locally a problem. In Austria, tillage operations are widely adopted in agriculture. It is assumed that P. americana is not likely to establish and become weedy under such conditions as the taproot will most likely be destroyed.
Sources
Follak S, Schwarz M, Essl F (2022) Notes on the occurrence of Phytolacca americana L. in crop fields and its potential agricultural impact. BioInvasions Records 11 (in press).