Agriculture and forestry

Khareba Volodymyr Vasylovich − Doctor of Agricultural Sciences, Professor, Academician of the NAAS, Acting Academician-Secretary, Office of the Presidium of the National Academy of Agrarian Sciences of Ukraine (01010, Kyiv, Mykhailo Omelyanovicha-Pavlenko St., 9. e-mail: prezid@naas.gov.ua.).

Chernenko Dmytro Serhiyovych − Postgraduate Student of the Institute of Vegetable and Melon Growing of the NAAS (62478, Ukraine, Selektsiyne village, Kharkiv district, Kharkiv region, Instytutska St., 1, e-mail: ovoch.iob@gmail.com).

One of the forgotten crops is turnip, which originates from Western Asia. It belongs to the oldest vegetable plants and has been cultivated by man for over 4 thousand years. Successful cultivation of turnip is possible if the elements of cultivation technology are observed. Therefore, the purpose of the research was to establish the optimal sowing dates of turnip seeds and their impact on plant productivity and quality indicators of the root crop in open ground conditions. The research was conducted in 2023–2024 in the conditions of Western Polissya of Ukraine. Turnip seeds were sown in the 2nd and 3rd decades of April, and the 1st, 2nd and 3rd decades of May. The varieties Zolota Kulya, Purpurlepop, Purpurova and Geisha were used in the experiment. The control was the variant in which the seeds of the Zolota Kulya variety were sown in the 2nd decade of April using a wide-row method with a row spacing of 45 cm. The experiment determined the duration of interphase periods of growth and development of turnip varieties, the mass of leaves and turnip roots, the total yield of root crops and their quality depending on the time of sowing seeds. The study was carried out in three replicates using the randomized block method. As a result of growing turnips, it was found that at early sowing dates (the second and third decades of April), the germination period is shorter, and at sowing seeds at later dates, the germination period is extended and ranges from 8 to 9 days. When sowing turnip seeds in the third decade of April, there is a more active growth of root crops; when sowing in the first and second decades of May, active plant growth and root crop development are observed; when sowing seeds in the third decade of May, better development of the leaf surface is established. The largest mass of root crops is characterized by the turnip variety Purpulepop (388.3 g) when sowing seeds in the second decade of April. The optimal seed sowing date, which contributes to obtaining a higher yield of turnips, is the second and third decades of April, where the value can vary from 23.8 t/ha to 24.9 t/ha of root crops. When sowing seeds in the first and third decades of May, the yield of turnip roots decreases. The highest yield of root crops is characterized by the turnip variety Purpulepop 24.9 t/ha and 24.6 t/ha, which exceeds the yield of the Zolota Kulya variety by 1.5 and 1.2 t/ha, respectively. The highest dry matter content is possible when sowing seeds in the first decade of May for all turnip varieties - (18.89 − 19.51 %), with the varieties Purpurova (19.51 %) and Geisha (18.89 %) standing out; the highest sugar content (10.66 and 11.34%) or an increase of 2.88 % and 2.2 % is possible for early sowing dates (second and third decades of April) for the Purpurova variety; an increase in protein content by 12% is possible for the Zolota Kulya variety when sowing seeds in the third decade of April, and an approximate value is characterized by the Purpulepop varieties (6.63%) when sowing seeds in the second decade of May and the Purpurova variety - 6.61% (third decade of April); vitamin C in root crops can increase by 7-10% for the Purpulepop and Purpurova varieties, the seeds of which should be sown in the second-third decade of April and the first decade of May.

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