Frost resistance of tomato seeds and the degree of naturalisation of Lycopersicon esculentum Mill. in Central Europe

Lycopersicon esculentum frequently occurs on Central European river banks and on ruderal sites as a non-native species. It is usually considered as a casual, which receives its seed supply only from waste and waste water. But field observations show an increasing abundance of plants managing to develop ripe fruits within the growing season. A germination experiment shows a degree of frost resistance of the produced tomato seeds which is sufficient to survive winter temperatures to a considerable extent. It appears therefore that with respect to habitat temperatures Lycopersicon esculentum progressively can naturalise in Central Europe so that it will become a regular agriophyte on natural and semi-natural habitats of European river banks.