Scientifically validated items of growing technology disclosed for cos lettuce marketable products in the conditions of Forest-Steppe of Ukraine. Impact of environmental factors onto growth and development of Lactuca sativa var. longifolia L. plants. Sowing terms established for the seed of cos lettuce at field-seeded growing. Development parameters are quoted for plant productivity indices and marketable product indices for cos lettuce of national and foreign breeding. According to VCU characteristics a typical model has been designed for the cos lettuce indices of suitability for dissemination in Ukraine.

Purpose. Providing a scientific rationale for the practical application of analysis of variance elements to determine the range of morphological and value for cultivation and use (VCU) characteristics of Romaine lettuce ‘Skarb’ variety. Results. The Romaine lettuce ‘Skarb’ variety was identified by the type of display of quantitative (QN) identification characteristics. VCU characteristics of the var. longifolia L. varieties were determined and statistically processed. The author focused on practical application of histogram and variation curve of phenotype morphological characteristics when performing the uniformity test. The correlation between quantitative characteristics of lettuce leaf and head was observed when plant productivity was developing. Romaine lettuce yield value was verified statistically. Thresholds were established for the indices under study, confidence intervals were defined over the years of study. Conclusions. The use of Lewis stability factor (S.F. = Xmax/Xmin) allowed to establish the stability of each characteristic display. Practical application of the histogram and variation curve for determining code of display of quantitative morphological characters and the range of VCU characteristics of the Romaine lettuce ‘Skarb’ variety was scientifically grounded.