Soybean Seed Inoculant and Fungicidal Seed Treatment Effects on Soybean

Abstract

Several new bacterial inoculant products have been introduced for use as a soybean [ Glycine max (L.) Merr.] seed treatment. A 3‐yr study over 16 site‐years determined whether soybean seed inoculation had an effect on grain yield, if yield or growth differences occurred between soybean treated with commercial inoculant products, and whether use of seed‐applied fungicide resulted in yield benefits or interacted with commercial inoculants. Eight commercial inoculants were tested both with and without seed‐applied fungicidal treatment in a split‐plot randomized complete block configuration. Use of soybean inoculant raised soybean yield in 6 of 14 site‐years in fields that had been in soybean rotation. The average yield increase as a result of soybean seed inoculation at these 14 site‐years with a previous history of soybean cropping was 85.6 kg ha −1 Differences between inoculant products were observed only at first‐time soybean sites. Fungicidal seed treatment improved yield on 3 of 16 site‐years and only interacted with inoculant on the two first‐time soybean sites.