Image processing for seed stainability detection through tetrazolium test

To evaluate the application of the image processing method (RGB and Lab methods) compared to the visual evaluation method for determining the seed viability or stainability of wheat (Triticum aestivum) and hairy vetch (Vicia villosa) using tetrazolium test, a factorial experiment based on a completely randomized design with three replications was conducted in the laboratory of Department of Mechanical and Biosystems Engineering of the Faculty of Agriculture, Tarbiat Modares University in 2019. The experimental factors included methods for determining seed stainability (visual assessment, RGB, and Lab methods), two plant species (wheat and winter vetch), physical stratification (cross cutting, longitudinal cutting, sanding, needling, and control), and duration of exposure to tetrazolium (10 and 24 hours). The results showed that the stainability of seeds exposed to tetrazolium for 24 hours was higher than those exposed for 10 hours. The highest stainability of seeds was observed in the longitudinal cutting treatment for both wheat and hairy vetch species in the all three determining seed stainability methods. The RGB and Lab methods showed the highest stainability percentage for wheat and hairy vetch seeds, respectively, where the seeds were cut longitudinally. Therefore, the RGB and Lab image processing technique can be used as a fast, precise, and new method for determining the seed viability of crops and weeds through the tetrazolium test.