Battie-Laclau, PatriciaLaclau, Jean-Paul [UNESP]Piccolo, Marisa de CassiaArenque, Bruna CersózimoBeri, ConstanceMietton, LaurianeMuniz, Marta R. AlmeidaJordan-Meille, LionelBuckeridge, Marcos SilveiraNouvellon, YannRanger, JacquesBouillet, Jean-Pierre2014-05-272014-05-272013-10-01Plant and Soil, v. 371, n. 1-2, p. 19-35, 2013.0032-079Xhttp://hdl.handle.net/11449/76689Background and Aims: Recent studies showed a positive tree response to Na addition in K-depleted tropical soils. Our study aimed to gain insight into the effects of K and Na fertilizations on leaf area components for a widely planted tree species. Methods: Leaf expansion rates, as well as nutrient, polyol and soluble sugar concentrations, were measured from emergence to abscission of tagged leaves in 1-year-old Eucalyptus grandis plantations. Leaf cell size and water status parameters were compared 1 and 2 months after leaf emergence in plots with KCl application (+K), NaCl application (+Na) and control plots (C). Results: K and Na applications enhanced tree leaf area by increasing both leaf longevity and the mean area of individual leaves. Higher cell turgor in treatments +K and +Na than in the C treatment resulting from higher concentrations of osmotica contributed to increasing both palisade cell diameters and the size of fully expanded leaves. Conclusions: Intermediate total tree leaf area in treatment +Na compared to treatments C and +K might result from the capacity of Na to substitute K in osmoregulatory functions, whereas it seemed unable to accomplish other important K functions that contribute to delaying leaf senescence. © 2013 Springer Science+Business Media Dordrecht.19-35engCell sizeCell turgorExpansionKLeaf areaLeaf lifespanLeaf longevityNaNutrientOsmotic potentialSoluble sugarsArtigo10.1007/s11104-013-1663-7WOS:000324882500003Acesso restrito2-s2.0-84884816917