Uman NUH | today: 05/20/2019

Species composition of diseases of leaf lettuce in conditions of closed soil during winter-spring cultivation

Author(s) Ketskalo V.V., Candidate of Agricultural Science, Associate Professor of Department of Vegetable Production, Uman National University of Horticulture, Ukraine
Polishchuk T.V., , ,
Category The Agronomy
year 2018 issue Випуск №92. Частина 1
pages 91-99 index UDK 635-1/-2:635.52:631.544.4-977
Abstract In recent years, areas under green vegetable crops are increasing intensively both in the open ground and in structures of enclosed soil. Leading position on growing among them is a leaf salad, which is due to a rapid trend to increase its consumption in Ukraine. As a rule, green crops are grown without the use of pesticides and the "Production – ecological safety" scheme operates here. Due to the fact that the list of varieties of lettuce is constantly updated, it became necessary to determine their resistance to disease and analyze the specific composition of diseases of leaf lettuce in conditions of closed soil during the winter-spring cultivation in the greenhouse of the Uman National University of Horticulture. Phytosanitary inspection of plants of leaf lettuce in the greenhouse during winter-spring cultivation during 2013–2015 shows that the more common and harmful diseases were gray rot, mucous bacteriosis (wet rot), peronosporosis (downy mildew) and black leg. An insignificant amount of leaf lettuce was affected by rhizoctonia (radical decay), on some plants noted virozes (mosaic, chlorosis) and white rot. It was established that over the years of the study the seedlings of leaf lettuce in the period from the emergence of shoots to the formation of a rosette with 3–4 leaves were affected by a black leg, the development of which was insignificant (up to 2,2 %). During the 2013–2015 while the growth of leaf lettuce was dominated by mucous bacteriosis and gray mold, and the maximum index of their development during the harvesting period averaged 19,3 % and 15,5 %, respectively, over the years of the study. An insignificant indicator of the development of peronosporosis – 6.0%, white rot – 1,5 %, radical decay (rhizoctonia) – 2 % and almost complete absence of viroses caused by mosaic viruses and necrotic chlorosis – 0,5 %. On the grades of the Dutch selection Hagino and Frillis, the symptoms of disease were minimal, and the greatest spread of diseases was observed on the salad of the leaf Kudryavets Odessa. The remaining studied varieties were distinguished by a rather high level of resistance, however, in some plants the signs of disease were clearly manifested.
Key words leaf lettuce, closed ground, disease, resistance.
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