Table 1 The alleviating effect of high-nitrogen and -potassium fertilizers on the impacts of drought stress on leaf area, color coefficient, and stomatal opening size in Hosta ‘Guacamole’

Leaf area (cm²)

65.4 ± 11.6^a

56.0 ± 8.66^b

55.0 ± 6.03^b

58.2 ± 14.4^c

78.4 ± 5.92^a

68.3 ± 8.88^b

Leaf numbers

3.4 ± 0.61^a

3.5 ± 0.61^a

3.5 ± 0.79^a

4.4 ± 1.07^b

9.1 ± 2.37^a

8.5 ± 2.32^a

Size of stomatal opening (px)

27.6 ± 2.88^a

20.9 ± 6.95^b

13.3 ± 3.51^c

-

-

-

Chlorophyll content (SPAD)

15.4 ± 2.58^a

16.4 ± 2.17^a

12.9 ± 1.60^b

12.3 ± 3.47^b

25.4 ± 5.63^a

21.2 ± 5.76^a

Color coefficient of chromameter

L^*

60.2 ± 1.66^b

60.1 ± 1.50^b

62.6 ± 3.12^a

59.5 ± 5.50^a

47.3 ± 6.46^b

55.2 ± 3.62^a

a^*

−18.1 ± 11.0^a

−18.4 ± 10.9^a

−21.8 ± 0.8^a

−21.4 ± 0.98^a

−19.6 ± 1.67^a

−23.7 ± 2.91^b

b^*

46.7 ± 1.29^b

46.5 ± 1.23^b

49.5 ± 1.88^a

46.3 ± 4.07^a

33.8 ± 7.59^b

43.9 ± 3.41^a