The influence of mineral fertilizer rates on the table grapes productivity under drip irrigation in Crimea

Abstract

Purpose: to determine the effect of mineral nutrition rates on the growth and development indicators, as well as the productivity of table grape varieties of different ripening periods with drip irrigation in the Republic of Crimea. Materials and methods. The studies were conducted in 2024–2025 on an experimental plot established in November 2021 in the Belogorsk district. The plot soils are southern chernozems, heavy loamy and medium loamy. The field experiment included six variants: without fertilizers (K₁), the calculated rate of N₈₀P₆₀K₆₀ (К₂) and its variations of ±10 % and ±20 %. 70 % of phosphorus and potassium fertilizers were applied in the fall under primary cultivation. Plant nutrition was carried out through fertigation with drip irrigation. The studies were conducted with the table grape varieties Veles (very early), Livia (early), and Preobrazhenie (mid-early). Results. The transition from the variant without fertilizers to the calculated rate ensured a shoot length increase of 11.7–19.5 %, the length of the ripe part of the shoot of 10.5–16.3 %, the leaf-area duration of 10.0–33.3 %, and the photosynthetic net productivity of 10.0–22.2 % (this indicator did not change for the Livia variety). The application of mineral fertilizers increased the grape yield relative to the variant without fertilizers by 38.3–78.8 %, depending on the variety and application rate; at the calculated rate, the increase was 54.3–62.1 %. The Livia variety demonstrated the greatest responsiveness to fertilizer application in terms of growth indicators, while Veles demonstrated the highest yield in relative terms (62.1 % of the K₁ control at a K₂ rate). For each variety, dependences on the yield increase and the total amount of mineral fertilizer applied were obtained. Conclusions. Dependencies for calculating rational rates of mineral fertilizers for the cultivation of table grapes of various maturity groups (very early, early, and mid-early) under drip irrigation in the Republic of Crimea were determined. These dependences will allow the development of a mineral nutrition system for table grapes to achieve yields of 11.8–13.5 t/ha.