Study of seasonal development of the alien plant Solanum viarum Dunal under experimental conditions

Solanum viarum Dunal. is a pantropical plant of South American origin. It is a perennial herbaceous vegetatively mobile plant with powerful thorns. Every year it forms many large leathery fruits containing up to 50 thousand seeds on one plant, which allowed it to spread over large areas of warm frost-free regions of the Earth. It prefers to populate open light habitats, forming impassable thorny thickets. It contaminates pastures, forage lands, crops, uncultivated lands, urban areas. The weed is extremely drought-resistant due to its thick rhizomes that penetrate deeply into the soil, but are sensitive to low positive temperatures. It can grow on various soil types. It is considered an invasive species in many countries. Its main pathways are seeds dispersed by people, animals and birds.

In recent years, cases of S. viarum detections along roadside have been reported in protected areas in France (Christians and Maglio, 2020). The pest risk analysis for EPPO countries conducted in 2024 showed that the invasive potential of this species for the EPPO area has not yet been fully realized and the species was provisionally placed on a list for further observations (EPPO…, 2022). However, this information cannot but raise concerns in terms of possible phytosanitary  threats.

Solanum viarum is quite popular in ornamental gardening in Russia, as evidenced by offers to sell its seeds by various online retailers. As has been repeatedly noted, a significant number of alien species were initially cultivated as ornamental plants and only much later did characters indicating their invasive potential were known. And although this species populations are most likely not yet present on the territory of the Russian Federation, the question arises whether it can adapt in certain natural and climatic conditions of Russia, especially in connection with the ongoing global climate change.

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