Effect of herbicide treatment on milk thistle (Silybum marianum (L.) Gaertn) germination

The effect of herbicide treatment on milk thistle has been observed in the years 2010 and 2011 in the experimental field station Zabcice. The milk thistle variety "Silyb" was sown. In the first year the seeds were obtained from the company IREL, Ltd.; in the second year the seed harvested in the year 2010 were used. The phytotoxicity of used herbicides was observed during the vegetation period in both years (Stomp 400 SC, Refine, Butisan Star, Afalon 45 SC, Fusilade Forte, Glean + Starane and untreated control plot. In 2010 the harvest was performed in two terms due to the gradual ripening; in 2011 only once due to excessive rainfall. The achenes harvested in 2010 were evaluated according to following characteristics: yield (g.m(-2)), overflow of the sieve (%) (2.2, 2, and the rest), weight of thousand seeds (g), light and dark achenes germination in the year of harvest and light and dark achenes germination after storage (%). In 2011 following characteristics were evaluated: yield, germination ability and weight of thousand of seeds.