To determine if and how manganese deficiency in lupins can be overcome.

• Replicated trials at 22 sites were sown in factorial design of two rates of manganese sulphate (0 and 32 kg/ha), drilled with the superphosphate (200 kg/ha) at seeding, and two rates of manganese foliar spray (Mangasol®) at 0 and 10 1/ha) applied at flowering.
• Harvest yields were obtained, and the number of split seeds recorded in the grain sample.
• Manganese significantly (P < 0.05) increased grain yields and reduced the proportion of split seeds in the grain sample at 10 of the 22 sites (see table).
• Manganese significantly (P < 0.05) reduced the proportion of split seeds at 8 non-yield responsive sites, and produced no response at 4 sites (see table). Cultivar effects were not apparent. Concluded that a Mangasol® foliar spray applied at flowering is a more reliable means of controlling manganese deficiency in lupins than is the drilling of manganese at seeding time.
• Wide-spread aerial applications of Mangasol® have been commercially applied in the two seasons since these trials. The method is cost-effective, and in most cases coincides with insecticide application.