Abstract

Plants produce and store many products of secondary metabolism that are released into the environment and can influence direct or indirectly on nearby organisms. Thus, this study investigated the allelopathic potential of extracted soil solution from an area with cover crops according to germination and early development of beggartick. Soil solution was extracted in an area where black oats, turnip and hairy vetch were grown. The concentrated solution was tested in sand substrate while the dilutions were tested in 100; 200; 300 and 400 ml L^-1 germitest paper substrate, plus the control treatment on beggartick. Germination was tested for 10 days and the early development for 20 days. Twenty seeds or seedlings were distributed in gerbox, with three replications and the experimental design was completely randomized (CRD). Soil solution showed considerable changes on beggartick germination only in the last collections, mainly with extracted solution in an area cropped with turnip and hairy vetch. The results, in this case, were more significant when germitest was used than with sand substrate. Therefore, it is recommended these cover crops in crop rotation, aiming to reduce beggartick infestation in a long term.

Key words: Allelopathy, Weeds, crop rotation, secondary metabolites.