Effects of allelochemicals in Brassica napus L. residues on the germination of weeds

Abstract

We investigated the inhibitory influences of winter oilseed rape residues on weeds. Residues after harvest on the germination of Galium aparine L. (i). 3-months after residues decomposition in soil on the germination of Sinapis arvensis L. and Tripleurospermum perforatum L. (ii). 7-months after decomposition on the germination of Sonchus arvensis L. The total contents of phenolic compounds in soil in decomposing rape residues significantly decreased after 3-months. The glucosinolates content was higher in rape stubble compared to upper plant part of threshed crop residues at harvest. The content of volatile organic compounds in rape residues 7-months after decomposition was the highest, comparing with other decomposition periods, except threshing remains. These results suggested that decomposing winter oilseed rape residues in soil were allelopathic and hence, influenced the agroecosystems in the following two-years period.