Fig. 2From: Alleviation of iron deficiency in pear by ammonium nitrate and nitric oxideEffects of exogenous NH4NO3 and NO on SPAD value and photosynthetic performance of iron-deficient pear leaves. The data are expressed as the mean ± SD (n = 6). Different letters indicate significant differences at P < 0.05 (LSD test)Back to article page