Irrigation and potassium fertilization effects on plant growth, tuber yield, quality, and water use efficiency of potato

Abstract

Potato (Solanum tuberosum L.) requires high levels of water and potassium to achieve optimal yield and quality. This is of importance for the sustainable agriculture, and therefore, it is quite concern of agronomists to define the proper irrigation level and potassium rates in potato. In this study, we tested three irrigation levels (full irrigation (I₁₀₀), 66% full irrigation (I₆₆; 33% deficit), 33% full irrigation (I₃₃; 66% deficit)), and six potassium doses (K₀:0 kg ha⁻¹ of K, K₁:40 kg ha⁻¹ of K, K₂:80 kg ha⁻¹ of K, K₃:120 kg ha⁻¹ of K, K₄:160 kg ha⁻¹ of K and K₅:200 kg ha⁻¹ of K) in Agria. The study was conducted in Niğde (Central Anatolia, Türkiye, 37°56′31.8′′N 34°38′04.2′′E) as a two-year field experiment. In the experiment, the respective values were recorded for each variable; plant height 36.0–92.0 cm, maturation period 82.0–98.0 days, number of stem per plant 3.4–4.7, number of tuber per plant 4.1–7.7, tuber yield per plant 247.1–846.2 g, marketable tuber ratio 79.4–99.4%, discarded tuber ratio 0.6–5.7%, secondary structured tuber ratio 0.0–16.6%, total tuber yield 11.8–38.7 t, dry matter 19.2–21.6%, specific gravity 1.072–1.087 g cm³, and starch 13.2–15.9%. Besides, it was determined that the optimum irrigation × potassium interaction was achieved at I₁₀₀×K₃ and I₁₀₀×K₄ in terms of plant and yield parameters, and I₃₃×K₃ and I₃₃ × K₄ in terms of tuber quality parameters. In our work, we concluded that a water need of average 590–720 mm (not including the effective rainfall amount) and potassium supply of 120–160 kg ha⁻¹ in Central Anatolia will be optimal for the potato cultivation. The findings of this study will contribute to potato cultivation practices by providing proper information about the optimal irrigation need and potassium dose.