The article deals with the results of study early-maturing potato varieties according to the method of tuber pre-planting preparation. The essential influence was pre-plant germination of potato tubers of early varieties at harvest. Determined way of pre-plant sprouting tubers allows 60 days from planting to obtain highest marketable yield of early potato. Pre-plant germination improves the yield of early potato. Sprouting tubers in pallets allow 60 days from planting to get the highest yield of early potato varieties Naghoroda – 15.4 t/ha Tiras – 15.2 t/ha Santarka - 13.9 t/ha.

Potato – one of the most common crops in the world. In Ukraine potato is a product of daily food and raw materials for the processing industry. For the majority of population it is a basis of food security. Therefore, today the urgent task is the yield gain and enlargement of consumption period. To obtain high yields of early potato is of great importance to chose properly a potato variety. Recently, the State Register of Plant Varieties of Ukraine includes over 60 different potato varieties with its economic ripening process. It is known that the degree of viability of each class is determined by the set of its bio-tech features and relations with growth conditions. Along with the impact of modern technology, soil and climatic factors (weather condition zones) are the most accurate assessment of varieties given by the practiced farmers from different zones. For the collective farms, gardeners and farmers are considerably interested in grouping of early ripening potato varieties to obtain new ones in the early periods.

In terms of Right-Bank forest-steppe in dark gray podzolic soils the studied varieties were uneven developed and grown during the growing season. Phenological observations showed the duration of the shoot planting due to varietal features and methods of sprouted tubers. Preplanting germination of potato tubers affected the appearance of shoots on all tested cultivars. Thus, in conducted germination test of tubers, shoots emerged on 5-10 days earlier than the control ones. The shortest period of "shoot planting" - 19-20 days for marked varieties Award, Melody, in the variant where tubers germinated in pallets. The longest period of "shoot planting" (31-32 days) was observed in Vedruska and Karlyk varieties where tubers did not germinate. This pattern was observed at the origin of varieties of the budding and flowering phases.

Biometric measurement results indicate the presence of varied intensity growth and development of potato plants, depending on the type and methods of germination. The study found out that more intensive vegetative mass index was observed in variants where tubers germinated on the techniques and pallets. Among all tested cultivars after 60 days from planting it was Naghoroda variety that involved 65-68sm highest plant height and leaf surface area of the largest bush 0,68-0,70m2. Results of dynamic undermining after 60 days from planting confirmed that early potato yield significantly depends on preplant germination of tubers and varietal features. More intense accumulation of early potato crop occurred in the germinated varieties Naghoroda, Tiras. After 60 days of planting, the most marketable yield was obtained in the following grades: Naghoroda-15,4 t/ha, Tiras-15,2 t/ha and Santarka-13,9 t/h. The similar varieties Vumir-12,5 t/ha, Melodya-12,7 t/ha Skarbnutsya-13,5 t/ha had slightly smaller values. Analyzing the results of the research it should be noted a pattern of productivity of the sprouting tuber harvest methods. Thus, light germination of tubers increased yield-producing power in all tested cultivars -3,0 to 2,0 t/ha compared with the control ones. In this case, the highest early harvest was 4,3-5,9 t/ha in the form where the tubers germinated in pallets.

Structural analysis of early variety studies indicates that the potato variants participating in the pre-plant germination had more product tubers under a bush. The given results revealed that the increase of commercial harvest was put into effect not only by increasing the number of tubers under a bush, but also due to their mass.

In the second undermining (after 70 days from planting) yield gain for ten days in the tested cultivars reached 3,4-7,3 t/ha. The highest marketable yield for this period formed such varieties as Tiras-1,98 t/ha, Naghoroda-20,1 t / ha, Santarka – 20,5 t/ha where tubers germinated in pallets. During potato harvest season in biological maturity of the tested cultivars Tiras-26,3 t/ha, Naghoroda-28,9 t/ha, Skarbnutsya-30,4 t/ha provided the highest yield grade.

To obtain early production of potato in the Right-bank Forest-steppe zone of Ukraine the most suitable varieties are Naghoroda, Tiras, Santarka. Pre-plant germination improves the yield of early potato. Sprouting tubers in pallets allow 60 days from planting to get the highest product yield of early-maturing potato varieties Naghoroda – 15.4 t/ha Tiras – 15.2 t/ha Santarka - 13.9 t/ha.

Key words: potato, sprouting potato, early maturing varieties, productivity.