Epidemiological development and chemical control of Drechslera sorokiniana (Sacc.), Subram. and Jain on spring barley
1993
Weisig, V. (Goettingen Univ. (Germany). Inst. fuer Pflanzenpathologie und Pflanzenschutz) | Fehrmann, H.
During 3 years (1986 to 1988), experiments were carried out to study the epidemics and chemical control of Drechslera sorokiniana leaf blotch in spring barley (cv. 'Apex'). When naturally infected seeds were sown, typical symptoms and damages were observed first on the seedlings and on the primary leaves. The development of the epidemics became progressive mainly at heading stage (EC 55) as the leaves on different levels up to the flag-leaf became infected successively resulting into heavily diseased plants. In field experiments, effectiveness of chemical control was compared by using seed treatments with either Baytan U (a.i. triadimenol, fuberidazol plus imazalil) or the Elanco fluessig (imazalil plus nuarimol), by spraying with Folicur (tebuconazol), or by a combination of both. Seed treatment reduced the proportion of infected kernels at harvest, leading to more emergence of seedlings after sowing and lowering the incidence on young plants at early development stages. Results from investigations on the disease frequency on different plants organs suggest a secondary infection from the primary leaves. Seed treatment decreased the disease severity on leaves on a moderate scale only. On the other hand, spraying tebuconazol yielded a highly significant control of leaf infection, and this was largely independent of seed treatment as well as of timing or frequency of spray applications. Both seed treatment and spraying were yield effective. Seed treatment increased yield mainly by increasing the density of the plant stand, while spraying increased grain yield mainly by a higher thousand-grain-weight. Combining the above two methods of fungicide application did not produce an additional increase in yield
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Эту запись предоставил ZB MED Nutrition. Environment. Agriculture