Table 4 Water deficiency rates and some irrigation system types effectiveness on leaf photosynthetic pigments and proline contents, cell sap osmotic pressure, opened stomata percentage, and leaf bound water content percentage of Washington navel orange leaves (2021–2022 seasons)

First season (2021)

 ETc 100%

0.22^a

0.11^a

35.68^c

25.95^c

90.94^a

45.21^b

 ETc 80%

0.21^b

0.10^b

94.83^b

27.88^b

83.10^b

45.52^b

 ETc 60%

0.20^c

0.09^c

119.93^a

28.85^a

81.88^b

49.09^a

 DIS

0.21^a

0.10^a

79.75^b

27.19^a

86.65^a

47.19^a

 MSIS

0.21^a

0.10^a

87.21^a

27.92^a

83.96^b

46.02^b

 ETc 100% × DIS

0.23^a

0.11^a

26.35^e

25.48^e

93.02^a

44.86^d

 ETc 100% × MSIS

0.22^b

0.10^b

45.00^d

26.42^d

88.86^b

45.57^d

 ETc 80% × DIS

0.21^c

0.10^b

81.16^c

27.09^c

85.47^c

46.57^c

 ETc 80% × MSIS

0.20^d

0.09^c

108.51^b

28.67^b

80.73^d

44.47^d

 ETc 60% × DIS

0.20^d

0.09^c

131.75^a

29.01^a

81.46^d

50.14^a

 ETc 60% × MSIS

0.20^d

0.09^c

108.10^b

28.68^b

82.30^d

48.03^b

Second season (2022)

 ETc 100%

0.22^a

0.10^a

34.11^c

26.32^c

91.66^a

44.16^b

 ETc 80%

0.21^b

0.10^a

91.81^b

28.62^b

85.16^b

44.74^b

 ETc 60%

0.20^c

0.09^b

118.52^a

29.97^a

83.20^b

47.30^a

 DIS

0.22^a

0.10^a

78.23^b

27.76^b

88.29^a

46.03^a

 MSIS

0.21^b

0.10^a

84.73^a

28.85^a

85.07^b

44.77^b

 ETc 100% × DIS

0.23^a

0.11^a

24.74^e

25.84^c

93.94^a

44.15^d

 ETc 100% × MSIS

0.22^b

0.10^b

43.48^d

26.80^b

89.38^b

44.18^d

 ETc 80% × DIS

0.21^c

0.10^b

79.02^c

27.52^b

87.59^c

45.75^c

 ETc 80% × MSIS

0.20^d

0.09^c

104.61^b

29.72^a

82.74^d

43.74^d

 ETc 60% × DIS

0.20^d

0.09^c

130.94^a

29.91^a

83.33^d

48.19^a

 ETc 60% × MSIS

0.20^d

0.09^c

106.10^b

30.04^a

83.07^d

46.40^b