Effect of Abiotic Stresses on the Nondestructive Estimation of Rice Leaf Nitrogen Concentration

Table 4

Analysis of variance for specific leaf weight (SLW), chlorophyll concentration, and leaf N concentration (Ch_a and N_a: area based; Ch_dw and N_dw: dry weight based). The analysis was conducted separately for salinity (±SAL), sulfur (±S), and phosphorus (±P) treatments. Included are mean treatment values across varieties and sampling dates, separated for each stress treatment.

	SLW g m^−2	Cha g m^−2	Na g m^−2	Chdw mg g^−1	Ndw mg g^−1
Salinity
Treatment (T)(a)	ns	∗	∗∗∗	ns	∗∗∗
Variety (V)	∗∗∗	ns	∗∗∗	ns	∗∗∗
Sampling (S)	∗∗∗	∗∗∗	∗∗∗	∗∗∗	∗∗∗
T×V	ns	ns	ns	ns	ns
T×S	ns	ns	ns	∗∗	∗
V×S	ns	ns	ns	ns	ns
T×V×S	ns	ns	ns	ns	ns
Treatment; mean(b)
–SAL	44.9 a	0.24 b	0.90 b	6.34 a	22.0 b
+SAL	44.3 a	0.26 a	1.06 a	6.37 a	25.1 a
Sulfur
Treatment (T)(a)	ns	∗	ns	∗∗∗	ns
Sampling (S)	∗∗∗	∗∗∗	∗∗∗	∗∗∗	∗∗∗
T x S	ns	ns	ns	ns	ns
Treatment; mean(b)
+S	46.6 a	0.28 b	1.08 a	6.22 b	24.3 a
–S	44.7 a	0.31 a	1.12 a	6.97 a	25.0 a
Phosphorus
Treatment (T)(a)	ns	∗∗∗	ns	∗∗∗	∗∗
Variety (V)	ns	∗	ns	ns	ns
Sampling (S)	∗∗∗	∗∗∗	∗	∗∗∗	∗∗∗
T×V	∗∗	ns	ns	ns	ns
T×S	ns	ns	ns	ns	∗∗∗
V×S	∗	ns	ns	∗	∗
T×V×S	ns	ns	ns	ns	ns
Treatment; mean(b)
+P	45.0 a	0.33 b	1.42 a	7.39 b	31.7 b
–P	44.0 a	0.39 a	1.44 a	8.89 a	33.1 a

(a) Significance levels indicated for the ANOVA are ns: 𝑃>.05; ∗:.05 ≤ 𝑃 ≤.01; ∗∗:.01 ≤ 𝑃 ≤.001; ∗∗∗: 𝑃<.001.
(b) Values in a column followed by the same letter are not significantly different at 𝑃>.05 according to the Tukey test.