Evaluation of Different Methods in Seed Dormancy Breaking and germination of Redroot Pigweed (Amaranthus retroflexus)

Extended Abstract Introduction: Weeds, representing the most important biological stress, reduce the efficiency of water use, bring about food waste, shading and secretion of toxic substances, leading to a 10 to 100 percent reduction in crop yields. The first step in weed control is understanding the biology and life cycle of the weed, particularly its eco-physiological characteristics. Dormancy in weed seeds, including Redroot Pigweed seeds, is common. Therefore, given the importance of studies into dormancy breaking and germination of weed seeds, the present study was conducted to identify the methods for dormancy breaking and the germination of Redroot Pigweed seeds. Materials and Methods: This research started in autumn 2013 by collecting Redroot Pigweed seeds from fields of Alajujeh village, Khoda Afrin County, East Azerbaijan Province. Subsequently, the study was conducted at the Laboratory of the Faculty of Agriculture of the University of Maragheh in 2014 and 2015. For data analysis, the GenStat 12.1 program was used and the Duncan test was used at 5% probability level to compare the averages. Excel 2013 was also utilized for drawing the diagrams. Results and discussion: Analysis of variance demonstrated that the effect of treatments on germination percentage and germination rate in Redroot Pigweed seeds was significant at 1% probability level and on mean germination time, at 5% probability level. The results showed that among the treatments studied, seeds held for 18 months were the most efficient in breaking seed dormancy of Redroot Pigweed so that the highest germination percentage (92%), germination rate (29.18 seed/day) and lowest mean germination time (4.2 day) were obtained in seed holding treatment. Pre-chilling treatment also had significant effects on stimulating germination. Given that treatments of seeds held at low temperatures and pre-chilling accelerate the germination process and increase germination percentage, having precise information about these traits enables to study, manage and control this troublesome weed more effectively. Conclusions: In general, the results of this study show that out of the treatments, holding seeds for 18 months at 6 ° C is the best method for solving the dormancy problem of seeds of Redroot Pigweed weeds.