Using image analysis to study the allelopathic potential of wheat cultivars against wild barley (Hordeum spontaneum)

ABSTRACT: Due to increase in the number of herbicide-resistant weeds and environmental concerns in the use of synthetic herbicides, there have been considerable efforts in designing alternative weed management strategies. Crop plants may adversely affect weeds through allelochemicals, which may be released directly or indirectly from live or dead plants. Therefore, the allelopathy potential of nine wheat cultivars against wild barley was evaluated in this study. A special transparent growth box containing black cloth enclosed in it was used to provide a seedbed which allowed the allelochemicals movement along the seed bed and facilitating the use of image analysis. Images were captured every 12 h to evaluate wild barley seedling co-growth with wheat cultivars over time. The allelopathic activities of wheat cultivars affected wild barley growth differently. Falat and Azar2 were more allelopathic cultivars; they inhibited the root elongation of wild barley seedlings by 57.36% and 47.29% respectively. There was clear correlation between root spread of wild barley and seedling growth, suggesting the potential of root spread as an important determinant of allelopathic activity. This method provides a consistent and reliable tool for analyzing the changes in root architecture of allelochemical receiver plants during the exposure to allelopathic neighbors.