Follow manufacturers' instructions for proper application of inoculant. All inoculant sold in Canada is registered under the Fertilizers Act, and Agriculture and Agri-Food Canada tests inoculants regularly to ensure they meet the guaranteed number of bacteria stated on the label. The inoculant contains live cultures of bacteria and should be kept refrigerated or cool and moist and out of direct sunlight. To assess the effectiveness of rhizobium nodules after planting, dig plants and examine the roots. Effective nodules will be a pink colour when sliced open.
Ineffective nodules are pale green or white inside.
Generally, nodulation is visible one month after seeding, and the number of nodules increases until flowering. Plants stressed by weather or disease may not nodulate. High levels of soil nitrogen may inhibit nodule formation and activity. Soils should be sampled to zero to six and six-24 inch depths. Beans are very sensitive to seed-placed fertilizer.