Table 3 Leaf mineral (nitrogen; N, phosphorus; P, and potassium; K⁺) contents and ionic homeostasis (K⁺/Na⁺ and Ca²⁺/Na⁺ ratios) of sugar beet plant as influenced by indole‒3‒acetic acid (IAA) and nitrogen (N) rate (data average for 2022/23 and 2023/24 cropping seasons)

IAA (mg L^− 1)

IAA₀

21.7 ± 1.0c

2.74 ± 0.14b

28.8 ± 0.80c

1.01 ± 0.05b

0.38 ± 0.03b

IAA₁₅₀

22.3 ± 1.1b

2.97 ± 0.14a

29.2 ± 0.79b

1.02 ± 0.05b

0.39 ± 0.03b

IAA₃₀₀

24.3 ± 1.2a

3.04 ± 0.16a

29.4 ± 0.84a

1.08 ± 0.06a

0.42 ± 0.03a

N rate (kg ha^− 1)

N₂₄₀

19.3 ± 1.3b

2.39 ± 0.16b

26.1 ± 0.85b

0.86 ± 0.03c

0.30 ± 0.01c

N₂₉₀

23.2 ± 0.5a

3.08 ± 0.07a

29.9 ± 0.36a

1.03 ± 0.03b

0.38 ± 0.01b

N₃₄₀

25.8 ± 0.7a

3.28 ± 0.1a

31.3 ± 0.55a

1.21 ± 0.04a

0.51 ± 0.02a

IAA × N rate

IAA₀

N₂₄₀

18.5 ± 2.3a

2.26 ± 0.28a

25.8 ± 1.52a

0.84 ± 0.06a

0.29 ± 0.02a

N₂₉₀

22.0 ± 0.6a

2.90 ± 0.11a

29.7 ± 0.64a

1.02 ± 0.06a

0.36 ± 0.02a

N₃₄₀

24.5 ± 1.0a

3.05 ± 0.16a

30.9 ± 0.97a

1.16 ± 0.07a

0.48 ± 0.05a

IAA₁₅₀

N₂₄₀

19.0 ± 2.4a

2.45 ± 0.30a

26.2 ± 1.55a

0.85 ± 0.07a

0.30 ± 0.03a

N₂₉₀

22.8 ± 0.7a

3.16 ± 0.10a

30.0 ± 0.64a

1.03 ± 0.06a

0.37 ± 0.02a

N₃₄₀

25.3 ± 1.2a

3.31 ± 0.16a

31.4 ± 1.01a

1.18 ± 0.07a

0.49 ± 0.05a

IAA₃₀₀

N₂₄₀

20.5 ± 2.6a

2.46 ± 0.32a

26.3 ± 1.59a

0.87 ± 0.06a

0.32 ± 0.02a

N₂₉₀

24.8 ± 0.8a

3.19 ± 0.14a

30.1 ± 0.67a

1.06 ± 0.07a

0.40 ± 0.03a

N₃₄₀

25.7 ± 1.3a

3.48 ± 0.20a

31.7 ± 1.02a

1.30 ± 0.08a

0.55 ± 0.04a

p-value

IAA

< 0.001^**

< 0.001^**

< 0.001^**

0.044^*

< 0.001^**

N rate

< 0.001^**

< 0.001^**

< 0.001^**

< 0.001^**

< 0.001^**

IAA × N rate

0.997^ns

0.910^ns

1.000^ns

0.779^ns

0.862^ns

CV (%)

10.8

6.1

6.0

7.7

9.2