Nitrogen-induced variations in leaf gas exchange of spring triticale under field conditions

• Published in: Acta physiologiae plantarum 2017-09, Vol.39 (9), p.1-12, Article 193
• Main Authors: Janusauskaite, Daiva, Feiziene, Dalia, Feiza, Virginijus
• Format: Article
• Language: English
• Subjects: Aging; Aging (artificial); Agriculture; Ammonium; Ammonium nitrate; Biomedical and Life Sciences; Chlorophyll; Conductance; Crop yield; Exchanging; Fertilization; Fertilizer application; Fertilizers; Gas exchange; Grain; Growth stage; Leaves; Life Sciences; Nitrates; Nitrogen; Original Article; Photosynthesis; Photosystem II; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Resistance; Soil analysis; Spring; Statistical analysis; Stomata; Stomatal conductance; Transpiration; Triticale; Urea; Variance analysis; Water use; Water use efficiency
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-017-2495-5

Nitrogen (N) is the key factor limiting photosynthetic processes and crop yield. Little is known about the response of leaf gas exchange of spring triticale ( Triticosecale Wittm.) to N supply. The effect of N fertilizers on different gas exchange variables, i.e., photosynthetic rate ( A ), transpiration rate ( E ), stomatal conductance ( g s ), instantaneous water use efficiency (WUE) and maximum quantum yield of photosystem II (PSII) ( F v / F m ), chlorophyll index (SPAD, soil–plant analysis development), and the relationship of these variables with yield were studied in spring triticale grown under field conditions. Six treatments of N—0, 90, 180, 90 + 30, 90 + 30 + 30 kg ha −1 (applied as ammonium nitrate, AN) and one treatment of N 90 + 30 + 30 kg ha −1 (applied as urea ammonium nitrate solution, UAN) were compared. The analysis of variance showed that throughout the triticale growing season, N fertilization had significant effects on A , WUE, g s and SPAD. On average, N fertilizer application increased A values by 14–70%. E and F v / F m values were not influenced by N fertilization levels. The effect of growth stage and year on gas exchange variables and F v / F m and SPAD was found to be significant. At different growth stages, A values varied and maximum ones were reached at BBCH 31–33 (decimal code system of growth stages) and BBCH 59. With aging, values of A decreased independently of N fertilization level. The gas exchange variables were equally affected by both fertilizer forms. The interplay among grain yield, leaf gas exchange variables, F v / F m and SPAD of spring triticale was estimated. The statistical analysis showed that grain yield positively and significantly correlated with A and SPAD values throughout the growing season.