Impact of climatic factors on growth and development of Cichorium Endivia in greenhouse in Leningrad region, Russia

The paper discusses the results of the study of the effect of climatic factors on the yield and biometric indicators of various varieties of endive chicory (Cichorium endivia (L.)) over a two-year study grown in the summer-autumn period in the plastic greenhouses on the experimental plots of the St. Petersburg Agrarian University, Pushkin, Russia. The plants of the genus Chicory are known and valued for their unique medicinal and nutritional properties. Total of 14 varieties of domestic and foreign Cichorium endivia breeding were studied. The study was carried out in 2015 and 2016years that were sharply differed in the amount of precipitation and temperature. The climate of Leningrad region is characterised with humid and long-lasting cold season. The aim of the research was to identify the variety of endive chicory that is most suitable and tolerant for the climatic conditions of Leningrad region, Russia. During the growing season the plant biometric parameters such as plant height (cm), rosette diameter of leaves (cm), and number of leaves (pieces) were measured. During harvesting, additional parameters such as biomass of plants and leaves, the area of the assimilation surface were determined. The decrease in plant biometric parameters during the phenological observations in September 2016 was associated with an increased amount of precipitation in July-August. The results showed that the variety "Broad Betavian fullhearted" was the most sensitive to the adverse effects of weather, showing the largest variation in biometrics over the studied years. In plants of this variety the mass of leaves decreased by 9.2 times, the area of the assimilation surface was reduced by 11.6 times, while the crop shortfall in 2016 was almost 90%. The varieties "Green curled" and "Scarola bionda" were the most tolerant to weather conditions. These varieties were characterized by the maximum yield in both years of research: "Green curled"-7.90 kg/m 2 and 2.87 kg/m 2 , "Scarola bionda"-8.06 kg/m 2 and 2.84 kg/m 2 in 2015 and 2016, respectively. Generally, the result of the study showed that most of the studied varieties were sensitive to the amount of precipitation and the number of sunny days. The study made it possible to identify the most sensitive and most tolerant varieties of endive chicory for growing in the Leningrad region.