Milk thistle (Silybum marianum (L.) Gaertn.) as a weed in sustainable crop rotation.

Abstract

Milk thistle - Silybum marianum (L.) Gaertn. can be a winter annual or a biennial medicinal plant. The assessment of the occurrence of milk thistle in sustainable crop rotation was conducted at the Experimental Base of Faculty of Agrobiology and Food Resources, SUA in Nitra in the years 2008- 2011. This study was focused on milk thistle as a weed in the sustainable farming system with the crop rotation of maize for grain, pea for grain, durum wheat and milk thistle. An actual weed infestation of maize, pea and durum wheat stands with milk thistle was evaluated before preemergence application of herbicides, in the spring time. Second screening of actual weed infestation of all stands in sustainable crop rotation with milk thistle was done before crops harvest. Screening of each field was made on 1 m 2 area with three replications. The three randomly established sample quadrants were situated minimally 10 m from field margin and apart from each other, respectively. The level of infestation was evaluated according to average density of weeds per square meter. Obtained data was statistically analyzed by Statistica 7.0, ANOVA, LSD test (p=0.05). As a plant from the family Asteraceae has a great