[Effects of foliage spraying sodium bisulfite on photosynthetic physiological characteristics of Citrus sinensis with sulphur deficiency].

The study with solution culture showed that Citrus sinensis plants with sulphur deficiency and with sulphur deficiency plus foliage spraying sodium bisulfite ( NaHSO3 ) halfway had notably decreased photosynthetic pigment content, soluble protein content, net photosynthetic rate (Pn), initial fluorescence (Fo) , maximum fluorescence (Fm) , photochemical efficiency (Fv/Fm) and electron transmit rate (ETR) , compared with those having normal sulphur supply. After 35 days of growth, their photosynthetic pigment content decreased by 23. 45% and 11. 32% , and soluble protein content decreased by 43. 43% and 25. 30% , respectively, while no significant differences were observed between the plants with sulphur deficiency plus foliage spraying NaHSO3 throughout the experiment and those having normal sulphur supply, suggesting that foliage spraying NaHSO3 could be an effective way to supply sulphur element to the C. sinensis with sulphur deficiency, but hard to rectify sulphur deficiency symptom when the plants suffered from a severe sulphur deficiency stress for a long time.