The article presents the results of studies on the impact of time of sowing and seed rate linseed varieties on yield and seed quality in terms of the central Polessye.

500 O-type lines of sugar beet hybrid components were studied according to their main economically valuable characteristics, namely, one-seed structure, germination readiness, productivity, sugar content and sugar yield. 13 best features were determined, herewith one-seed structure of most tested genotypes was observed at the level of 92-99% which appeared to be of nearly the same level during all the years of the research. On that ground they were included into the program for further research. The weight of seeds of the researched numbers ranged from 13,3 to 22,2 gr. The productivity of the researched O-type lines varied from 40,1 to 45,2 tons per hectare. Herewith, the highest productivity index was observed in 664bk 6 line with the average index 42,7 tons per hectare which ensured sugar yield 7,59 tons per hectare. The results of the research into the influence of low temperatures on seed germination readiness and capacity of O-type sugar beet lines were given. All the researched materials readily respond to conditions of germination and the seed germination readiness and germination capacity directly depend on the temperature. However, high indices of seed germination readiness and capacity under low temperatures is an essential feature of parent breeding materials in the breeding process while creating new hybrids which can be grown by means of intensive technologies. This will make it possible to sow heterosis sugar beet hybrids in earlier terms. It was suggested to use the best lines as parent components for development of heterosis hybrids which are able to ensure seed germination under low temperatures.

Purpose. To study the effect of AKM plant growth regulator on growth, development and yield formation of sunflower (Helianthus annuus L.) hybrids in hybridization plots under the conditions of the Southern Steppe zone of Ukraine. Methods. Laboratory tests, field study, statistical evaluation. Results. The results of studies devoted to determining the optimal AKM concentration for the treatment of seeds of the maternal and paternal lines, the effect of AKM on field germination, biometric parameters of sunflower plants, seed quality (F1) and yield are presented. Three hybrids of the Ukrainian selection, such as ‘Alpha’, ‘Logos’ and ‘Persei’ were studied during 2014–2016. Optimal concentration of AKM (0.0015 g/l) was defined. The vigor of seeds processed by AKM was higher than in check variety by 0.8–12.8 р.р. (♂); 0.4–10.7 p.p. (♀), laboratory germination – by 2.3–6.1 p.p. (♂); 3.5–6.2 p.p. (♀). In 2016, the sunflower plant height for all variants exceeded this parameter to be obtained for other years of the study. This could be explained by the fact that HTC in 2016 for the BBCH 00–39 period was 1.4 times higher than in 2015. In general, hybrids as the studied factor considerably influenced sunflower yield, and the share of the hybrid (factor A) influence is 33%. This should be considered when selecting hybrids for sunflower cultivation technologies in the Steppe zone of Ukraine. Conclusions. Hydrothermal conditions of the year had the maximum impact on the formation of seed quality and yield of sunflower plants of the hybrids under study, but when using AKM growth regulator for presowing seed treatment, this negative impact was reduced by an average of 23%.

Revealed main point of formation the matrix differences of lettuce seeds characteristics (Lactuca sativa L.), its correlation with other categories of heterogeneity. It’s been shown the ways of decreasing of the matrix differences of lettuce seeds characteristics with the aim to increase sowing quality of seeds.