Evaluation of sulfuric acid application in breaking dormancy of goosefoot and red-root amaranth seeds

To evaluate the effect of sulfuric acid (75%) on breaking the dormancy of the seeds of goosefoot (Chenopodium album L.) and red-root amaranth (Amaranthus retroflexus L.) as potato weeds, an experiment was conducted in Seed Technology Laboratory, Department of Agronomy, University of Mohaghegh-e-Ardabili, Ardabil, Iran in 2010 based on a Randomized Complete Design with three replications. The treatments included pretreatment of the seeds of both species with sulfuric acid (75%) for 0, 7, 14, 25 and 45 minutes. The results showed that with the increase in the duration of treatment with sulfuric acid (75%), the germination percentage of amaranth seeds increased from 2% to 78.5% and its germination rate increased from 0.8 to 4.4 but radicle length and weight decreased from 32 to 7.4 cm and from 0.00054g to 0.00001 g, respectively. There was no significant difference among the treatments of pretreatment with sulfuric acid for 7, 14 and 25 minutes. The highest and lowest germination rates were observed in 45-minute pretreatment with sulfuric acid and control, respectively. With respect to goosefoot seeds, no germination and seedling growth was observed after treated with sulfuric acid (75%).