Polar fraction toxicity obtained Amaranthus hybridus on the germination and seedlings of cowpea

Abstract

Introduction: Since the first implementation of synthetic herbicides in crop protection systems, weeds have continuously developed resistance. In this regard the phenomenon of allelopathy, which is expressed through the release of chemicals by a plant, has been suggested to be one of the possible alternatives for achieving sustainable weed management. Objectives: The present study aimed to investigate the effect of Amaranthus hybridus aqueous fraction on the germination and growth behavior of cowpea. Methodology: From the ethanol extract of A. hybridus leaves, the aqueous fraction was obtained,   which was considered the 100% concentration solution and from it dilutions were made, obtaining the other treatment solutions, posteriorly, the treatment solutions were used in two bioassays, germinative vigor and seedling growth and development. The germination percentage (% IG), the germination speed index (IVG), dry mass (MS) and radicle length (CR) and hypocotyl (CH) were evaluated. Results: The highest concentrations (60% and 100%) significantly decreased the IVG, CR and CH values and caused MS reduction, where they reduced the IVG value by 30.01% and inhibited root growth by 62.5 % and 64.67% respectively. For the length of the hypocotyl the concentration 100% inhibited the growth in 43.12% and in the accumulation of biomass the concentration 100% reduced the production in 75.75%. Conclusion: It is concluded that the aqueous fraction of the extract of A. hybridus is potentially phytotoxic mainly for the initial development of the seedlingKey - words: Phytotoxicity; Invasive plant; Vigna unguiculata.