Asclepias syriaca L.: Common milkweed

Asclepias syriaca L. (ASCSY, fam. Apocynaceae) is a weed originating from the northern parts of central, northeastern and southeastern America, as well vicinal areas Canada. The common milkweed was introduced to Europe at beginning 19th century honey, ornamental fiber/silk plant. Today, it occurs in many countries western Central (France, Austria, Czech Republic, Belgium, Germany, Lithuania, Slovakia, Hungary, Poland, Italy, Slovenia, Croatia, Serbia, Bosnia, Romania, Bulgaria Russia). first cases A. Serbia were noted 1920s. most on non-agricultural areas, where spreads surrounding cultivated areas. This perennial species can grow up 1.2 m has plenty underground adventitious buds which reproduces vegetatively. spherical umbels are axis upper leaves, flowers have pleasant smell purple deep purplish pink color. It diploid (2n = 22), self-pollinating plant, with hybridization between genus being very rare. One plant produce 1-6 fruits, every fruit containing 150-425 seeds. prefers fertile, well-drained soils, but also thrives dry soils. optimal development achieved moderately light warm, neutral slightly alkaline habitats, tolerating soil pH values 4-5. seeds germinate temperature 20-30ºC. Late frosts -1 -2ºC destroy young seedlings, while adult plants survive that temperature. allelopathic properties negative impact towards number plants, both crops (maize, soybean, sunflower Sorghum) weeds (Amaranthus retroflexus, Chenopodium album, Lepidium sativum Ambrosia artemisiifolia). affect seed germination crop leading significant yield reduction when its occurrence massive. control measures include: rotation, cultivation competitive crops, mechanical removal along roots, chemical recommended preventive method, using glyphosate triclopyr prevent entering fields.