Effects of Saffron Corm and Leaf Extracts on Early Growth of Some Plants to Investigate the Possibility of Using Them as Associated Crop

Abstract

Saffron intercropping with other plants needs to preliminary investigations about the possible negative interactions between saffron and associated crop. In this study, allelopathic effects of saffron leaf and corm extracts on germination and seedling growth indices of alfalfa (Medicago sativa), arugula (Eruca sativa) and rapeseed (Brassica napus) was investigated in six separate experiments based on completely randomized design. Experimental treatments were consisted of different levels of saffron leaf and corm extracts including 0, 0.75, 1.5, 3 and 6%. The maximum germination percentage of all selected crops was obtained at control treatment (on average 92%) and then decreased with increasing extracts concentration. So that, the germination percentage of arugula, canola and alfalfa in highest concentration of extracts were 18, 10 and 8% for leaf extract and 72, 68 and 93% for corm extract, respectively. The relatively similar trend was observed about germination rate, root and plumule lengths and dry weights. Therefore, the inhibitory effect of saffron leaf extract was more than corm extract on initial growth indices of studied plants. The lowest inhibitory effect of saffron leaf extract and even relatively high stimulatory effect of corm extract were obtained on alfalfa initial growth criteria. Considering the differences in allelochemicals mode of action and concentrations in laboratory bioassays with natural condition, it is necessary to investigate the effects of saffron residues on growth of selected associated crops in greenhouse and field scales for the final decision.