The article presents the results of studying the effect of the timing of planting seedlings on the growth, development, formation of the yield and yield of new varieties of sweet potatoes in conditions of irrigated typical gray soils. It was revealed that the timing of planting seedlings of new varieties of sweet potato significantly affects the growth, development and productivity of plants, and at the same time, the highest seedling yield (15.0-20.7 pcs. From 1 tuber), tall (158.1-191.6 cm ), branched (13.6-15.6 pcs. from a bush), with powerful tops, leafy (219-274 pcs.) or leaf area (0.66- 0.78 m2 from 1 bush) when planting seedlings 30 April. In terms of planting dates and the studied sweet potato varieties, the yield varied within 34.5-53.6 t/ha, and the highest yield of marketable tubers (50 t/ha or more) was observed when the seedlings were planted on April 30 in the sweet potato varieties Sochakinur, Toyloqi and Filial.