Pe. Olsen et al., ANALYSIS AND REGULATION OF LEGUME INOCULANTS IN CANADA - THE NEED FORAN INCREASE IN STANDARDS, Plant and soil, 161(1), 1994, pp. 127-134
Rhizobial inoculants for use in Canada are regulated and have been eva
luated 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 Prod
uction and Inspection Branch) as well as analysis (by Research Branch)
of approximately 220 inoculants and pre-inoculated seed products year
ly. Inoculant evaluation is based upon the calculated number of viable
rhizobia which would be provided per seed if the inoculant was applie
d at the manufacturer's recommended rate. Current standards are 10(3),
10(4), and 10(5) viable rhizobia per seed, of the proper cross-inocul
ation group, for small, intermediate, and large seeded legumes, respec
tively. 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 sus
tainable agriculture, taken together with advances in inoculant formul
ation technology, warrant an increase by a factor of ten in the minimu
m acceptable Canadian standards for legume inoculants and pre-inoculat
ed seed products.