EJPAU, 2021, Volume 24, Issue 1

Knowledge of agricultural seeds’ physical properties has significant importance for machinery and processing equipment design. Physical properties of flixweed (Descur ainia sophia L.) seeds were determined as a function of moisture content. Several properties were studied in the moisture range from 5.28 to 17.53% dry basis. Also, probability distribution of seeds’ principal dimensions were modeled by Gamma, Generalized Extreme Value, Lognormal, and Weibull functions. With increasing moisture content from 5.28 to 17.53%, properties including; length, width, thickness, geometric and arithmetic mean diameter, sphericity, specific surface area, volume, and projected area showed no specific trend. In contrast, the surface area increased from 6×10^-7 to 1×10^-6 m². The bulk and particle density decreased from 696.61 to 542.51 kg·m^-3, and 1217.50 to 1189.02 kg·m^-3, respectively. The porosity increased from 42.78 to 54.37%. The maximum external static angle of friction belonged to wood at all moisture content levels, followed by the iron and galvanized surfaces. At all moisture levels, the emptying angle of repose was more than the filling one.

One of the most critical challenges of determining tiny seeds’ engineering properties is their dimensions. In the present study, a method based on digital image processing was employed to investigate the moisture content’s effect on geometric properties of summer savory, basil, cress, and ajowan seeds. Also, the gravimetrical and frictional properties of the seeds were measured. Gamma, Generalized Extreme Value, and Weibull distributions were used to model the probability frequency distribution of the seeds’ length, width, and thickness. This research indicated that the application of the image processing technique could be an excellent method to measure dimensional parameters of tiny seeds. Results showed that, with an increasing moisture content of seeds, the 1000-seed mass increased for basil, cress, and ajowan seeds; but, summer savory seeds showed that increasing-decreasing trend. For all four plant spices, increasing moisture content will result in the bulk density decrement. The particle density of summer savory, basil, and cress seeds decreased due to moisture content increment. However, the particle density of ajowan seeds increased with increasing moisture content. Results of measuring the angle of friction on iron, wood, and galvanized surfaces showed that, in most cases, the angle of friction increased by increasing moisture content. Also, except for the filling angle of repose of summer savory, increasing trends were observed for the emptying and filling angle of repose due to moisture content increment.

The aim of this study is to compare the effects of different concentrations of nano and bulk titanium oxide on germination characteristics and the activity of antioxidant enzymes in Avena Sativa L. The titanium oxide nanoparticles diameter was determined about 40 nm using AFM, DLS, XRD analysis. In this study, based on a completely randomized design, seeds were placed in Petri dishes containing different concentrations of nano and bulk titanium oxide (50, 150, 250, 350 ppm). Three replications were considered for each concentration and the germination factors and antioxidant enzyme activity in the treated plant were compared with the control. The average data were compared using one-way ANOVA analysis and DUNCAN tests. According to the results, the following parameters of seedling vigor index, root length, dry weight, wet weight, guaiacol peroxidase enzyme, and polyphenol oxidase were statistically significant. The highest germination percentage, relative germination percentage, germination rate, weight germination index and shoot length were observed at 250 ppm bulk titanium oxide. In addition, the highest average germination time, seedling vigor index, optimum seedling index, and root length were observed in 50 ppm bulk titanium oxide treatment and the highest shoot length was observed in 250 ppm nano-titanium oxide treatment. In the enzyme activity, the highest activity of guaiacol peroxidase enzyme was observed in 150 ppm bulk titanium oxide treatment and the highest Polyphenol oxidase enzyme activity was observed in bulk titanium oxide 350 ppm treatment.