Solanum carolinense in Austria
Solanum carolinense (Solanaceae) is a rhizomatous perennial herb native to the USA which was accidentally introduced to Austria over 20 years ago. There are two varieties of the species, S. carolinense var. carolinense and S. carolinense var. floridianum. The latter is restricted to Florida and Georgia (USA). S. carolinense var. carolinense has been introduced to many regions of the world (EPPO region, New Zealand, and Japan for example) via contaminated soybean seeds and livestock fodder. In Austria, the distribution of S. carolinense is restricted to the southern part of the country and it is still considered to be a rare species: 36 records with occurrences in 0.3 % of all grid cells in Austria (where each grid cell is 33 km2). The highest number of occurrences are confined to the surroundings of the town of Leibnitz in southern Styria. A number of records are from crop fields (maize, soybean and oil-pumpkin). However, there are a small number of records of the species in ruderal habitats. Although the species has not spread rapidly in Austria, the increased number of records within grid cells indicate an incipient spread. The author highlights that S. carolinense is an example of an emerging weed in Austria. Spread on a local scale is increasing, and it is likely to spread in Austria and beyond. Awareness raising amongst farmers is needed and a management strategy should focus on control and containment, coupled with machinery cleaning to limit contamination.
Follak S (2019) Distribution and small-scale spread of the invasive weed Solanum carolinense in Austria. EPPO Bulletin, DOI: 10.1111/epp.12644