Field experiments were carried out at the FAMV/UPF, in 2002, to evaluate whether seed treatment with fungicides was able to influence the process of lesion expansion by barley (Hordeum vulgare) net blotch. Barley seeds of the cultivars BR 2 and MN 698 were treated with triadimenol at 40 g i.a./100 kg seeds. The seed treatment was combined with single or double sprays of a triazol fungicide (tebuconazole), or a triazol + strobyrulin (epoxiconazole + pyraclostrobin), at different plant growth stages. Lesion size and disease severity were assessed at 62, 79, 88, 95, 103, and 111 days after planting. The use of seeds with a low incidence of infection, seeds treated with fungicide, and foliar sprays significantly reduced the process of lesion expansion. The number of sprays, wheter one or two, and the type of fungicide did not influence lesion expansion. The severity of net blotch was low, especially under seed treatment, which reduced the process of lesion expansion, an important component of barley leaf spot epidemics.
Pyrenophora teres; Hordeum vulgare; control
