The Effect of Septoria Diseases on the Yield of Winter Wheat

SUMMARY A partial control of Septoria diseases was obtained with frequent appl.ications of tank‐mix zineb. In the control Pl.ots traces of glume blotch ( S. nodorwn ) and a moderate attack of leaf disease (mainly S. tritici ) occurred, but the full spray programme increased yields by about 35 per cent. The disease did not develop until after ear emergence and the increased yields were due to an increase in grain weight. When only two sprays were applied, after ear emergence, the yield increase was about 10 per cent.