A Survey of Leaf Diseases of Spring Barley in South-west England
1972; Wiley; Volume: 21; Issue: 2 Linguagem: Inglês
10.1111/j.1365-3059.1972.tb01724.x
ISSN1365-3059
AutoresS. C. Melville, Carol A. Lanham,
Tópico(s)Plant Pathogens and Resistance
ResumoSUMMARY The incidence of leaf diseases was assessed in approximately 150 crops of spring barley in Cornwall, Devon and Dorset in 1967–69 inclusive. Estimates of the percentage area of the laminae of the two top leaves affected by each disease were inade at growth stage 11.1 (Feekes scale). Mildew, leaf blotch and brown rust were the main diseases, mildew being the most severe in two of the years. Disease incidence varied with location and cultivar. Leaf blotch was usually more severe in earlier than in later sowings but the effect of sowing date on mildew severity was not consistent. None of the diseases was significantly more severe in crops which immediately followed barley than in those which did not, but the level of mildew was significantly lower after barley than after other crops. Thousand‐grain weight determinations, made on samples from a proportion of the crops surveyed, correlated well with the amount of total disease on the top leaf. The estimated loss in grain yield from all diseases ranged from about 19 to 22 per cent over the three years. Leaf blotch was more severe and mildew less severe in the three south‐western counties than in England and Wales as a whole.
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