THE ZONAL VARIABILITY OF YIELD OF LEAF CUTTING LETTUCE VARIETY SNEZHINKA

Abstract

Purpose. Determine the dependence of yield of cutting lettuce variety ‘Snezhinka ‘on the hydrothermal coefficients of the Left bank Forest-steppe and Polissya zones, and analyze the parameters of the zone's adaptive of varieties. Methods. Field studies, statistical methods for determining ecological variability. Results. The results of researches on determining the dependence of productivity of cutting variety ‘Snezhinka’ on the hydrothermal coefficient in the zones of the Left bank Forest-steppe and Polissya of Ukraine are presented. The optimum values of the GTK for obtaining the maximum yield in the conditions of the Left bank Forest-steppe make up 0,8–1,0, in the Polissya – 1,2–2,0. In conditions of Polissya, the influence of weather conditions on the yield of cutting lettuce was the lowest, which is confirmed not by high values of the coefficient of elasticity (0,00053–0,00155). Relative stability of variety is greater in the Forest-steppe (20,24 %), that is, in the data of the soil-climatic conditions for the variation of weather conditions, stable high productivity is not guaranteed. But in the conditions of the Forest-steppe on the parameter bi of cutting lettuce variety ‘Snezhinka’ was more plastic (1,24), that is, in favorable weather conditions, showed relatively high yields. In the conditions of Polissya, on the contrary, variety ‘Snezhinka’ was less plastic (0,76) and with a lower level of relative stability of genotype (15,94 %). The breeding value of genotype for the variety of cutting lettuce ‘Snezhinka’ in the zone of Polissya was higher (4,59). Conclusions. In the zone of the Left bank Forest-steppe, according to the fluctuations of the year cultivation of the sum of active temperatures 1076-1318 oC and the amount of precipitation 56,6–193,6 mm, the yield of cutting lettuce ‘Snezhinka’ was 6,7-12,2 t/ha. In the zone of Polissya, the ratio of precipitation to the sum of active temperatures almost did not affect the formation of yields at its fluctuation from 0,65 to 1,48. The dependence of yield formation in the zones of the Forest-steppe and Polissya on the coefficient of elasticity, respectively, was 0,05 and 0,26, indicating the favorable conditions of natural zone of the Left-bank Forest-steppe for the development of seedlings. The general and specific adaptive ability of variety Snezhinka was higher in the Forest-steppe zone (0,75 and 3,93 respectively); The largest breeding value of variety is characteristic for the zone of Polissya (4,59).

Keywords

• leaf lettuce
• hydrothermal coefficient