PM 9/32 (1) Solanum carolinense

Abstract

Specific scope: This Standard describes the control procedures aiming to monitor, contain, and eradicate Solanum carolinense.

Specific approval and amendment: First approved in 2024–09.

Solanum carolinense (Solanaceae) is a perennial herb native to North America (Wahlert et al., 2015). The species has several weedy attributes (e.g., reproduces vegetatively, rapid growth, prolific seed production, grows in a variety of biotic and abiotic conditions) (Bassett & Munro, 1986). The species was introduced into the EPPO region most likely in the middle of the 20th century.

Solanum carolinense is regarded to be a major agricultural problem. It is a common weed in many crops and pastures and affects crop yield and quality (Follak, 2020; Van Wychen, 2020), it is considered toxic to livestock (Bassett & Munro, 1986) and a host to many crop diseases and pests (Wahlert et al., 2015).

In the EPPO region, S. carolinense occurs in different habitats including banks of major rivers (e.g. the Waal; Dirkse et al., 2007), ruderal habitats (e.g. roadsides, port areas; Pérez et al., 2020), pastures and crop fields (Follak, 2020; Klingenhagen et al., 2012). The spread of S. carolinense is largely driven by human activities. Propagules of S. carolinense can be spread by agricultural machinery with contaminated soil attached both within fields and from field-to-field. Additionally, management and/or construction works in habitats that act as corridors for spread (e.g. roadsides) may facilitate the spread of the species (Follak, 2020; Wehtje et al., 1987). The establishment of S. carolinense by root fragments is assumed to be very successful, as the species can grow vegetatively from very small fragments (Ilnicki & Fertig, 1962; Miyazaki, 2008).

In 2022, S. carolinense was added to the EPPO A2 List of pests recommended for regulation as quarantine pests (EPPO, 2022a). The species is regulated by a number of EPPO countries (EPPO, 2022b), such as Azerbaijan, Kazakhstan, Jordan, Russia, Ukraine and Uzbekistan (all A1 List) as well as in Belarus and Israel (Quarantine pest) and Georgia (A2 List).

Further information on the biology, distribution and economic importance of Solanum carolinense can be found in Wahlert et al. (2015) and EPPO (2022b).

EPPO member countries at risk are advised to prepare monitoring activities and a contingency plan for the eradication and containment of this pest.

Regional cooperation is important, and it is recommended that countries should communicate with their neighbours to exchange views on the best programme to implement, in order to achieve the regional goal of preventing further spread of the pest.

For the efficient implementation of monitoring and control at a national level, cooperation between the relevant public bodies (e.g. NPPOs, Ministries of Environment, Ministries in charge of transport, water management), as well as with other interested bodies (associations) should be established.

Staff of organizations in charge of the monitoring of the species should be trained to recognize the plant at all stages in its lifecycle, even when present as small populations. This may include staff of NPPOs, botanists, agronomists, farmers, nature conservation managers, municipal authorities and road and rail maintenance workers. As this plant has the potential to grow in a range of habitats, citizen science projects may be implemented to encourage landholders and other citizens to report sightings of S. carolinense.

Regular surveys (see ISPM 6: Surveillance; FAO, 2018) are necessary to determine the geographical distribution of the plant and its prevalence. Monitoring can concentrate on areas that are climatically suitable and most vulnerable to colonization. It should be carried out in likely places of introduction of S. carolinense, such as disturbed habitat complexes and arable land. High risk places of introduction include, summer crops, such as maize and soybean and surroundings of grain and fodder warehouses, oil mills, grain processing factories and fodder industry factories where potentially contaminated plant material is stored or processed.

Any eradication programme for S. carolinense in the case of recently detected populations is based on the delimitation of the infested area within the country and the application of measures to both eradicate and prevent further spread of the pest. The feasibility of eradication depends on the size and designation of the infested area, the density of the population and the accumulated seed bank, and accessibility of the site. Eradication may only be feasible in the initial stages of infestation.

Measures are described in Appendix 1.

The containment programme for S. carolinense in the case of established populations is based on the application of measures to prevent further spread of the species in country or between neighbouring countries.

Measures are described in Appendix 2.

Regional cooperation is essential to promote phytosanitary measures and information exchange in identification and management methods. NPPOs can provide land managers and stakeholders with identification guides and facilitate regional cooperation including information on site-specific studies of the plant, control techniques and management. Professionals (e.g. administration, foresters) should be informed about the threat to natural and managed land, and about preventive measures. Integrated management, involving different sorts of land managers and various management measures will be more effective and efficient.