Peculiarities of the seed productivity formation of tyfon (Brassica campestris var. oleifera f. biennis D.C. × B. rapa L.) plants under the effect of cultivation technology

Abstract

Purpose. To reveal the peculiarities of the formation of indicators of individual seed productivity of tyfon plants under the effect of the agrotechnical components, such as the width of the rows and the rates of mineral fertilizers. Methods. The research was conducted in the years 2018–2021 at the Nizhyn Agricultural Technical Institute (Chernihiv region) according to generally accepted methods. The scheme of the field experiment provided for the cultivation of tyfon variety 'Orakam' under different methods of sowing (width between rows 15, 30 and 45 cm) and rates of mineral fertilization (without fertilizers, N80P60K60 and N120P90K90). Results. The highest indicators of seed productivity were obtained at a row width of 15 cm against the background of the application of the mineral fertilizers N80P60K60. In particular, the weight of seeds from one plant in this version of the experiment was 8.17 g, of which 1.72 g was the share of the main stem, and the remaining 6.45 g was the share of the side shoots of the first order. In the control option (width between rows 15 cm without fertilizing), these indicators were 7.45; 1.45 and 6.00 g, respectively. In the case of increasing the width of the rows to 30 and 45 cm on the background of application of N80P60K60, the weight of seeds per plant was lower compared to the 15 cm option by 0.36 and 1.15 g, and on the background of N120P90K90 – by 0.50 and 1.18 g, respectively. In all variants of the experiment, the main share in the structure of the individual productivity of crop plants (~ 80%) was occupied by the seed crop formed on their lateral shoots. Accordingly, the share of the yield from the main stem was approximately 20%. The variation of this percentage ratio depending on the impact of the investigated agrotechnical measures (both fertilizer rates and the method of sowing) had only a tendency character, as it did not exceed the experimental error. Conclusions. An increase in the width of the rows in the cultivation of tyfon leads to a significant decrease in the individual productivity of its plants, regardless of the use of fertilizers. Moreover, a clear regularity is followed: the wider the rows, the smaller the seed mass from one plant. To a large extent, the formation of seed productivity of crop plants is influenced by the application of fertilizers. More effective in this regard is the N80P60K60 rate, in the plots with which, for all treatments of the width of the rows, a significant increase is observed compared to the control of the seed mass from the plant. At the same time, when the rate of fertilizers increased to N120P90K90, a significant decrease in the weight of seeds per plant was found, compared to both the control without fertilizers and N80P60K60. The most optimal option for combining both elements of agricultural technology is the cultivation of tyfon at a row width of 15 cm against the background of N80P60K60 application.