Sowing and Planting

Invasive species for Poland

Both cultivated and wild plants, considered as weeds under certain conditions, can be a very big problem in agricultural production. Mild winters can lead to potato tubers overwintering in the ground, emerging in spring and even, in the case of varieties producing maturing seed, to the emergence of seed potato emergence.

Potato self-sowing in some crops is very difficult to control. Some herbaceous plants (e.g. coriander) emerging as volunteer seedlings in sugar beet can constitute a weed that cannot be controlled with standard herbicides. Common ruderal plants, brought into fields where ploughing has ceased altogether, find optimum growing conditions that cannot be kept under control by standard weed control methods – this is often the case with goldenrod. These species, like others, are identified as undesirable species with a significant impact on yield and quality.

Living organisms have a natural ability to adapt to new environments. However, when they appear in an environment where they were not previously found, they may lose out in competition with native plants, find their own niche or, by finding good conditions for development, even threaten the species found there that are typical of the local agrocenosis. The greatest threat is posed by alien plant species that thrive in new conditions, reproduce rapidly and begin to expand, occupying and displacing native species – we call them invasive species. In extreme cases, they occupy entire ecosystems, thereby impoverishing and destroying them. They can also carry diseases and parasites to which native species are not immune. Their cultivation is prohibited and their occurrence should be limited as much as possible. Invasive species in Poland are those listed in the Annex to the Regulation of the Minister of Environment of 9 September 2011. The list of invasive species posing a threat within the territory of the European Union countries is given in Commission Implementing Regulation (EU) 2016/1141 of 13 July 2016. It was developed with the participation of the Union Member States on the basis of risk assessment and scientific evidence.

Some plant species negatively affect the natural environment under certain conditions, including by transforming natural habitats, displacing native species through competition or restricting access to nutrients, water or light, such as Canada goldenrod. These species also often cause economic damage to the farm itself, where it is very difficult to get rid of them. They become a new ‘weed’ on the fields of the farm in question. They can often spread to subsequent fields with greater ease than arable crops. Wider knowledge of plant species that pose a threat to agricultural production can be obtained from the book: “Alien plants in Poland with particular reference to invasive species”, available online.