ANALYSIS AND REGULATION OF LEGUME INOCULANTS IN CANADA - THE NEED FOR AN INCREASE IN STANDARDS

Rhizobial inoculants for use in Canada are regulated and have been evaluated in a formal testing program since 1975. This program is carried out by Agriculture Canada under authority of the Fertilizers Act and involves inoculant strain and formulation registration (with Food Production and Inspection Branch) as well as analysis (by Research Branch) of approximately 220 inoculants and pre-inoculated seed products yearly. Inoculant evaluation is based upon the calculated number of viable rhizobia which would be provided per seed if the inoculant was applied at the manufacturer's recommended rate. Current standards are 10(3), 10(4), and 10(5) viable rhizobia per seed, of the proper cross-inoculation group, for small, intermediate, and large seeded legumes, respectively. Application of these standards means that some inoculants are considered ''satisfactory'' even though they yield test results as low as 9.4 x 10(6) rhizobia per gram. No standards are currently applied relative to permissible levels of contaminants in inoculant products, despite the fact that some inoculants contain many more contaminating microorganisms than they do Rhizobium cells. The demands of modern sustainable agriculture, taken together with advances in inoculant formulation technology, warrant an increase by a factor of ten in the minimum acceptable Canadian standards for legume inoculants and pre-inoculated seed products.