Is magnesium deficiency the major cause of needle chlorosis of Pinus taeda in Brazil?

查看全文 作　　者：Antônio Carlos Vargas [1]Motta;Shizuo [2]Maeda;Valdécio dos Santos dos Santos [1]Rodrigues;Tamires Maiara [1]Ercole;Stephen Arthur [3]Prior;Ana Elisa Lyra [1]Brumat;Amanda Pacheco Cardoso [4]Moura;Julierme Zimmer [5]Barbosa;João Bosco Vasconcellos [2]Gomes 机构地区：[1]Department of Soil Sciences and Agriculture Engineering,Federal University of Paraná,R.dos Funcionários,1540.,Curitiba,ParanáCEP 80035‑050,Brazil;[2]Brazilian Agricultural Research Company,Embrapa Florestas,Estr.da Ribeira–Br‑476,Km 111–Parque Monte Castelo.,Colombo,ParanáCEP 83411‑000,Brazil;[3]United States Department of Agriculture‑Agricultural Research Service,USDA-ARS National Soil Dynamics Laboratory,411 South Donahue Drive,Auburn,AL 36832,USA;[4]Reforestation Remasa,Rodovia PR 170–Km 522.,Bituruna,ParanáCEP 84640‑000,Brazil;[5]Federal Institute of Southeast of Minas Gerais,R.Luz Interior,360.,Juiz de Fora,Minas Gerais CEP 36030‑713,Brazil 出　　处：《Journal of Forestry Research》索引2024年第35卷第2期,共13页 基　　金：the National council for scientific and technological development(CNPq)and Higher Education Personnel Improvement Coordination(CAPES)。 摘　　要：Needle chlorosis(NC)in Pinus taeda L.systems in Brazil becomes more frequent after second and third harvest rotation cycles.In a study to identify factors contributing to yellowing needle chorosis(YNC),trees were grown in soils originating from contrasting parent materials,and soils and needles(whole,green and chlorotic portions)from 1-and 2-year-old branches and the first and second needle flush release at four sites with YNC on P.taeda were analyzed for various elements and properties.All soils had very low base levels(Ca^(2+),Mg^(2+)and K^(+))and P,suggesting a possible lack of multiple elements.YNC symptoms started at needle tips,then extended toward the needle base with time.First flush needles had longer portions with YNC than second flush needles did.Needles from the lower crown also had more symptoms along their length than those higher in the canopy.Symptoms were similar to those reported for Mg.In chlorotic portions,Mg and Ca concentrations were well below critical values;in particular,Mg levels were only one third of the critical value of 0.3 g kg^(-1).Collectively,results suggest that Mg deficiency is the primary reason for NC of P.taeda in various parent soils in Brazil. 关 键 词：Nutritional deficiency Forest management Soil depletion Pine foliar analysis Needle chlorosis