The influence of application of different variants of sowing terms, depth of tubers wrapping with comb method, variety and their interaction on the field sprouting of potato plants in the conditions of the Right Bank Forest-steppe of Ukraine was studied. It was established that the most favorable conditions for the appearance of simultaneous sprouts of potatoes of medium-early varieties on the experimental variants, were formed from the second planting season (May 03-05). On average, according to the terms of seeding of tubers with comb method of medium-early varieties, the best indicators of simultaneous sprouts are established from the second seeding period (03-05.05) – 92.1 %. The smallest of these indicators were noted from the third year of planting (13-15.05) – 88.0 %. Obtaining of simultaneous sprouts of potatoes of medium-early varieties in the years of research was influenced mostly by the depth of wrapping (factor B) – 43.1 %, terms of planting (factor A) – 22.2 %, and varieties (factor C) – 17.7 %.

The most favorable conditions for the appearance of simultaneous sprouts of potatoes of medium-ripe varieties developed from the second term of planting (03-05.05) and, on average, by factor A, the value of the indicator was the highest and amounted to 93.7 %, from the first planting date (23-25.04) – 92.6 %, respectively. The smallest index of simultaneous sprouts of medium-early varieties of potatoes was established from the third term of planting (13-15.05) at 92.1 %, but among the varieties, according to the given indicator, the variety Nadiyna is distinguished, simultaneous sprouts of which on average for the depth of tubers wrapping was 91.3 %. In determining the indicators of the appearance simultaneous sprouts of potatoes of medium-ripe varieties, according to the calculations of the dispersion analysis, it is confirmed that most of the time for this research was influenced by the terms of planting (factor A), 57.1 %, and the depth of tubers wrapping (factor B) 27.3 %. It should be noted that the varietal differences of the middle-ripe varieties (factor C) of 4.6 % practically did not affect the change in the index of potato simultaneous sprouts.

The obtained results of the research confirm that the varieties, terms of planting and the depth of tubers wrapping also affect the simultaneity of sprouts of medium-late varieties. So, among the terms of planting the second term is allocated (03-05.05) with a depth of tubers wrapping 2-3 cm and 6-8 cm. According to varieties, this indicator is: Oksamyt – 95.6 % and 95.9 %, Alladin – 94.1 % and 93.8 %, Dar – 95.9 % and 96.4%, respectively. The third term of planting was distinguished by ordinary results of the appearance of simultaneous sprouts of potatoes (13-15.05). On average, regardless of the depth of tubers wrapping, the rate of sprouts simultaneity in Oksamyt variety was 92.6 %, Alladin – 92.6 %, and Dar – 93.0 %, and on average, by factor A, it is 92.7 %. In addition, in the years of research with a prolonged cold spring, the sprouts simultaneity is somewhat lower, the sprouts appear much later, often liquefied and not aligned due to lesions of ricoctoniosis. As observed in our studies, a decrease in the depth of wrapping calls for more accurate and better performing of other technology requirements.

Also, with a small wrapping (2-3 cm) from the first term (23-25.04), the sprouts simultaneity of Oksamyt variety is 91.7 %, Alladin – 90.8 %, Dar – 92.4 %. However, in the second (03-05.05) and the third (13-15.05) periods of planting, these indicators were slightly higher, this is due to the fact that the small fractions of tubers (30-50 g) are planted in the majority.

According to the results of the dispersion analysis, the impact of the varieties was 6.4 %, the influence of the terms of the planting period was 40.4 %, the depth of tubers wrapping was 39.2 %. The combination of the influence of varietal characteristics, the terms of planting and the depth of tubers wrapping (factor ABC) was 3.0 %

Thus, most of all the simultaneity of sprouts of potato plants depended on the soil-climatic conditions, the terms of planting, the share of which in the change of this indicator was 22.2-57.1 %, the depth of tubers wrapping – 27.3-43.1 %, and the variety features of studied varieties are 4.6-17.7 %, respectively.

Key words: potatoes, varieties, terms of planting, depth of tubers wrapping, sprouting, dispersion analysis.