Cereal stubble mulching protects lupins from brown spot [Pleiochaeta setosa (Kirchn.) Hughes]

Abstract

Brown spot of lupins, initiated by rainsplash of soil-borne spores of the fungus Pleiochaeta setosa, was controlled by cereal stubble mulches. Stubble provided protection for longer in the season than fungicide seed dressing. At 1 site, late season pod infection was reduced by stubble mulch. Disease severity decreased with increasing quantity of stubble, but there was little benefit in retaining more than 2 t/ha of stubble. Grain yield was increased from 0.87 to 1.48 t/ha by retaining 2 t/ha of stubble at 1 site. The reduction in brown spot by stubble and fungicide was additive.