EFFECT OF SELENIUM SEED TREATMENT ON SELENIUM CONCENTRATIONS IN SOYBEANS

This study was conducted in Prince Edward Island (PEI), Canada, to det ermine the effect selenium (Se) treated seed on Se concentrations in s oybean seed (Glycine max). Seed Se concentrations were also compared t o those obtained with foliar applied Se. An application of 10 g Se ha( -1) as seed treatment raised soybean Se concentrations to more than 0. 5 mg kg(-1). Soybeans with these Se concentrations, when included in r ations at 200 kg t(-1) with other low Se ingredients, would produce ra tions exceeding 0.1 mg Se kg(-1), i.e., the minimum level required to prevent Se deficiency in livestock. Seed treatment with 100 g Se ha(-1 ) produced soybean Se concentrations greater than 10 mg Se kg(-1). Whe n included in rations at 200 kg t(-1) with other low Se feed sources, soybeans with such Se levels would produce rations in excess of the ma ximum tolerable dietary concentration of 2 mg Se kg(-1) dry matter. Ev en higher soybean Se concentrations were obtained from equivalent Se r ates when applied as foliar spray. In summary, treatment of soybean se ed with Se has a potential for improving the Se status of rations that would be formulated with ingredients originating from Se deficient ar eas.