Investigations on the occurrence of pathogenic fungi, insects and weeds in hemp (Cannabis sativa) in Austria

In 2020, a monitoring of pathogenic fungi, insects and weeds in hemp (Cannabis sativa) has been performed in the main cultivation areas of Austria. Thirty-seven hemp fields were sampled for the presence of pests and fungal pathogens. The identification work was carried out on the basis of morphological characteristics in the laboratory using routine methods of light microscopy. The survey of weed flora was conducted at a total of 42 hemp fields. Overall, 20 pathogenic fungal species belonging to 17 different genera, 65 arthropod species belonging to 27 families and 71 weed species belonging to 23 families were detected. Among these, Botrytis cinerea, Fusarium spp., Pseudoperonospora cannabina and Sclerotinia sclerotiorum represent the most important fungal species. Grapholita delineana, Helicoverpa armigera and Ostrinia nubilalis are the most harmful insect species and Chenopodium album, Amaranthus spp., Echinochloa crus-galli and Cirsium arvense were identified as the major weed species.