Success in growing an agricultural crop is considered to be the maximum realization of the potential of a variety, as well as a stable level of its yield over the years. In the article there are analysed the results of studies, conducted with the narrow-leaved lupine (Lupinus angustifolius L.) on the grey forest soil under the Forest-Steppe conditions. There are shown the peculiarities of the influence of hydrothermal conditions upon the duration of the period from sowing to the emergence of seedlings, interphase periods and the growing season, on the whole. An analysis is presented of the influence of weather conditions over the years of the research and agrotechnical measures upon the generative development of the plants, the formation of the crop grain yield, as well as its quality upon the variant, recommended for production, in comparison with the control variant. The weather conditions that developed during the period from sowing to full ripeness of the narrow-leaved lupine plants differed significantly over the years of research, influenced the duration of the period from sowing to germination (from 7 to 15 days), the growing season of the crop, on the whole, (from 79 to 101 days), growth and development of plants, and, as a result, - on the level of the yield. The seed yield in the experiment was unstable over the years even in the recommended production variant - from 3.28 to 2.10 t∙ha–1, that is, with a difference in the most favourable and unfavourable years of 1.18 t∙ha–1. The most favourable conditions for the formation of the crop were in 2016 on the variant, recommended for the production, and it provided for the application of N68P48K66, sowing lupine of the “Pobeditel” variety with an inter-row spacing of 45 cm, a seeding rate of 1.2 million germinating seeds t∙ha–1, treated with a bioinoculant with a bioprotectant, and also foliar top dressing with microfertilizer at the IV stage of plant organogenesis. The year 2020 turned out to be the most unfavourable, as evidenced by the minimum yield level of 2.10 t∙ha–1 and the index of the conditions of the year –0.51.