Mechanical seed processing improves the seed quality and reduces Karnal Bunt incidence in seed lots of varied wheat cultivars

Abstract

Quality seed production differs from commercial or grain crop production in several aspects. Special methods, precautions and operations are needed to deploy to produce seed of optimum quality. Seed processing influences the quality as well as marketability of seed and could be effectively deployed for elimination of diseased and damaged seeds from healthy seeds. Karnal Bunt (KB) of wheat is an internationally regulated disease and adversely affects the yield, seed appearance and trade. Therefore, effective seed testing and processing is vital to check the spread of disease through the seed. In the present study, efficacy of mechanical seed processing with recommended screen sizes were tested in six different wheat varieties and found that DBW-222 and DBW-187 shown highest recovery percentage of 90 and 89% respectively. HD-2967 and HD-3086 recorded seed recovery of 87 and 86% respectively. Lowest recovery was observed in case of durum wheat variety i.e. DDW-47 (85%). Further, eleven seed lots were tested for eight seed quality parameters and it was found that all carry over and fresh seed lot maintained germination above Indian Minimum Seed Certification Standards i.e. 85%. Further, processed seed lot showed lower KB infection as compared to un-processed seed lots, being minimum in processed seed lot of DBW-187 (0.15%) produced at Meerut. However, seed lot of DBW-187 and DBW-222 produced at Karnal recorded 0.17% KB incidence, followed by HD-3086 and HD-2967 (0.18%) both produced at Meerut. Further, DDW-47 recorded 0.23% of KB incidence which was higher among all the varieties after processing. Among two methods adopted for KB detection, NaOH method was found to be more sensitive (processed as well as un-processed seed lots) as compared to dry inspection method.