Validity of the Mechanical Threshing of Onion Seeds from the Point of View of Seed Quality

Background: The production of seeds for horticultural crops has seen a steady growth since 2006. Onion is one of the most widespread crops that followed this trend until 2013, undergoing a slight decline in 2016. Even though these crops are characterized by high economic value, they present some important issues such as high costs and labor required by some operations such as threshing. The purpose of this study is the evaluation of a patented and dedicated system for mechanical threshing throughout the evaluation of seed quality parameters. Methods: The study was conducted comparing seed samples mechanically threshed obtained from 12 companies and samples of the same batches manually threshed to determine the maximum qualitative potential. The chosen terms for comparison are the most important qualitative parameters included within ISTA standards for seed evaluation. Results: The mechanically threshed seeds show lower values for all the considered quality parameters compared to those found in the control samples. In the same way, there is also greater variability. Conclusions: The introduction of the dedicated mechanical systems allows the reduction of seed processing time while maintaining the quality standards within the limits of merchantability, but for obtaining higher standards, further analysis is necessary.