Effects of common stubble treatments and sowing sequences on scald disease (Rhynchosporium secalis) in barley crops

Abstract

Scald disease was absent in barley (Hordeurn vulgare L. cv. Clipper) grown in field plots where nonhosts of Rhynchosporiurn secalis had been grown successively, and from which living hosts of R. secalis had been absent for at least 18 months. In another field experiment, the burning or grazing of barley stubble containing R. secalis reduced the amount of scald disease of barley sown subsequently in the same plots, but only at early and not at later plant growth stages. Application of the fungicide maneb to burnt stubble gave no control additional to that given by burning. However, inoculation of field plots of barley at seedling emergence with differing amounts of R. secalis inoculum produced a corresponding range of levels of scald disease at both early and late growth stages.