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This work aimed to investigate the partial K-replacement by Na supply to alleviate drought-induced stress in Eucalyptus species. Plant growth, leaf gas exchange parameters, water relations, oxidative stress (H2O2 and MDA content), chlorophyll concentration, carbon (C) and nitrogen (N) isotopic leaf composition (δ13C and δ15N) were analyzed. Drought tolerant E. urophylla and E. camaldulensis showed positive responses to the partial K substitution by Na, with similar dry mass yields, stomatal density and total stomatal pore area relative to the well K-supplied plants under both water conditions, suggesting that 50% of the K requirements is pressing for physiological functions that is poorly substituted by Na. Furthermore, E. urophylla and E. camaldulensis up-regulated leaf gas exchanges, leading to enhanced long-term water use efficiency (WUEL). Moreover, the partial K substitution by Na had no effects on plants H2O2, MDA, δ13C and δ15N, confirming that Na, to a certain extent, can effectively replace K in plants metabolism. Otherwise, the drought-sensitive E. saligna species was negatively affected by partial K replacement by Na, decreasing plants dry mass, even with up-regulated leaf gas exchange parameters. The exclusive Na-supplied plants showed K-deficient symptoms and lower growth, WUEL, and δ13C, besides higher Na accumulation, δ15N, H2O2 and MDA content.

Pouco se sabe sobre o uso de substratos alternativos para produção de mudas de espécies nativas do Cerrado. Desta maneira, com o presente trabalho objetivou-se avaliar o efeito de diferentes composições de substratos (cama de frango e esterco bovino) misturados com solo arenoso no desenvolvimento de mudas de Hymenaea stigonocarpa e Tabebuia heptaphylla. Em viveiro em Nova Andradina, foram realizados dois experimentos (um para cada espécie) que comparavam dois substratos orgânicos (cama de frango e esterco bovino). Além dos tipos de substratos, foram testadas dez proporções entre esterco bovino (EB), cama de frango (CF) misturados com solo arenoso: EB1 = 100% esterco bovino; EB2 = 75% esterco bovino + 25% solo; EB3 = 50% esterco bovino + 50% solo; EB4 = 25% esterco bovino + 75% solo; T5 = 100% solo; CF6 = 100% cama de frango; CF7 = 75% cama de frango + 25% solo; CF8 = 50% cama de frango + 50% solo; CF9 = 25% cama de frango + 75% solo; e Controle = 100% substrato comercial. O delineamento utilizado foi inteiramente casualizado com oito repetições para cada tratamento, sendo feita a comparação desses substratos para cada espécie avaliada. As variáveis avaliadas foram: porcentagem de emergência de plântulas; tempo médio de emergência; altura da planta; número de folhas; diâmetro do colo; e acúmulo de massa seca de raiz e da parte aérea dessas plantas. Além dessas variáveis, foi avaliada também a concentração de macronutrientes na parte aérea das plantas. Por fim, a adição de esterco bovino e cama de frango beneficiou o desenvolvimento de mudas de Tabebuia heptaphylla, nas quais os substratos EB2, EB3, CF7 e CF8 apresentaram excelentes resultados comparados ao substrato comercial; por outro lado, as mudas de Hymenaea stigonocarpa responderam ao uso de cama de frango, ressaltando-se o uso de esterco bovino, visto que o substrato EB3 se sobressaiu em relação aos demais. Destaca-se que os substratos de baixo custo demonstraram resultados semelhantes ao substrato comercial.

Made available in DSpace on 2022-04-28T19:41:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Javna Agencija za Raziskovalno Dejavnost RS Rural and Environment Science and Analytical Services Division Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Phosphorus (P) and zinc (Zn) uptake and its physiological use in plants are interconnected and are tightly controlled. However, there is still conflicting information about the interactions of these two nutrients, thus a better understanding of nutritional homeostasis is needed. The objective of this work was to evaluate responses of photosynthesis parameters, P-Zn nutritional homeostasis and antioxidant metabolism to variation in the P × Zn supply of cotton (Gossypium hirsutum L.). Plants were grown in pots and watered with nutrient solution containing combinations of P and Zn supply. An excess of either P or Zn limited plant growth, reduced photosynthesis-related parameters, and antioxidant scavenging enzymes. Phosphorus uptake favoured photochemical dissipation of energy decreasing oxidative stress, notably on Zn-well-nourished plants. On the other hand, excessive P uptake reduces Zn-shoot concentration and decreasing carbonic anhydrase activity. Adequate Zn supply facilitated adaptation responses to P deficiency, upregulating acid phosphatase activity, whereas Zn and P excess were alleviated by increasing P and Zn supply, respectively. Collectively, the results showed that inter ionic effects of P and Zn uptake affected light use and CO2 assimilation rate on photosynthesis, activation of antioxidant metabolism, acid phosphatase and carbonic anhydrase activities, and plant growth-related responses to different extents. Center for Nuclear Energy in Agriculture University of São Paulo Biotechnical Faculty University of Ljubljana, Jamnikarjeva 111 Jožef Stefan Institute, Jamova 39 São Paulo State University College of Agriculture Luiz de Queiroz University of São Paulo Ecological Science Group The James Hutton Institute Distinguished Scientist Fellowship Program King Saud University College of Resources and Environment Huazhong Agricultural University São Paulo State University CAPES: 309380/2017-0 CNPq: 310572/2017-7

Eucalyptus, the most widely planted tree genus worldwide, is frequently cultivated in soils with low water and nutrient availability. Sodium (Na) can substitute some physiological functions of potassium (K), directly influencing plants’ water status. However, the extent to which K can be replaced by Na in drought conditions remains poorly understood. A greenhouse experiment was conducted with three Eucalyptus genotypes under two water conditions (well-watered and water-stressed) and five combination rates of K and Na, representing substitutions of 0/100, 25/75, 50/50, 75/25, and 100/0 (percentage of Na/percentage of K), to investigate growth and photosynthesis-related parameters. This study focused on the positive effects of Na supply since, depending on the levels applied, the Na supply may induce plants to salinity stress (>100 mM of NaCl). Plants supplied with low to intermediate K replacement by Na reduced the critical level of K without showing symptoms of K deficiency and provided higher total dry matter (TDM) than those Eucalyptus seedlings supplied only with K in both water conditions. Those plants supplied with low to intermediate K replacement by Na had improved CO2 assimilation (A), stomatal density (Std), K use efficiency (UEK), and water use efficiency (WUE), in addition to reduced leaf water potential (Ψw) and maintenance of leaf turgidity, with the stomata partially closed, indicated by the higher values of leaf carbon isotope composition (δ13C‰). Meanwhile, combination rates higher than 50% of K replacement by Na led to K-deficient plants, characterized by the lower values of TDM, δ13C‰, WUE, and leaf K concentration and higher leaf Na concentration. There was positive evidence of partial replacement of K by Na in Eucalyptus seedlings; meanwhile, the ideal percentage of substitution increased according to the drought tolerance of the species (Eucalyptus saligna < Eucalyptus urophylla < Eucalyptus camaldulensis).

Made available in DSpace on 2021-06-25T11:16:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Blossom-end rot (BER) is a physiological disorder related to calcium (Ca) deficiency in tomato fruits. However, adequate Ca supply is not sufficient to inhibit the BER incidence. The Ni-Ca interaction has increased the Ca content in Ni hyperaccumulators plants. However, studies with commercial plants are still incipient. The objective of this work was to evaluate the effect of Ni-Ca interaction in tomato plants, focusing on yield and incidence of BER. We carried out two trials. The first trial two Ca doses was used: sufficient Ca 0.70 g kg−1 (Ca S) and deficient Ca 0,35 g kg−1 (Ca D) and; four Ni doses applied via substrate (0.0; 0.5; 1.0 and; 2.0 mg kg−1). In the second trial, the same Ca doses of the first trial and four doses of Ni (0.0; 0.08; 0.42 and; 0.84 mM) applied, via foliar, at the beginning of flowering were used. We verified that the Ni-Ca interaction increased the tomato fruits yield, the shoot calcium accumulation reduced the BER incidence and increased the time of fruit color change (green to red). Even under stressed conditions such as a low Ca availability. Both Ni application ways showed positive results for fruit yield and decreased BER incidence. School of Agricultural and Veterinarian Sciences Path of Access Prof. Paulo Donato Castellane São Paulo State University (Unesp) Department of Animal Production Brazil University Center for Nuclear Energy in Agriculture University of Sao Paulo (USP) Department of Natural Resources Federal Institute of Mato Grosso Do Sul (IFMS) School of Agricultural and Veterinarian Sciences Path of Access Prof. Paulo Donato Castellane São Paulo State University (Unesp)

Eucalyptus are widely planted in regions with low rainfall, occasioning frequent drought stresses. To alleviate the stress-induced effects on plants growing in these environments, soil fertilization with potassium (K) may affect drought-adaptive plant mechanisms, notably on tropical soils with low K availability. This work aimed to evaluate the K dynamic nutrition in eucalyptus in response to soil-K and -water availabilities, correlating the K-nutritional status with the physiological responses of contrasting eucalyptus clones to drought tolerance. A complete randomized design was used to investigate the effects of three water regimes (well-watered, moderate water deficit, and severe water deficit) and two K soil supplies (sufficient and low K) on growth and physiological responses of two elite eucalyptus clones: "VM01" (Eucalyptus urophylla × camaldulensis) and "AEC 0144" (E. urophylla). Results depicted that the K-well-nourished E. urophylla × camaldulensis clone under severe water deficit maintained shoot biomass accumulation by upregulating the K-content in leaves and stems, gas exchange, water-use efficiency (WUEI ), leaf water potential (Ψw), and chlorophyll a fluorescence parameters, compared to E. urophylla clone. Meanwhile, E. urophylla with a severe water deficit showed a decreased of K content in leaves and stem, as well as a reduction in the accumulation of dry mass. Therefore, the K-use efficiency and the apparent electron transport rate through photosystem II were positively correlated in plants grown in low K, indicating the importance of K in maintaining leaf photochemical processes. In conclusion, management strategy should seek to enhance K-nutrition to optimize water-use efficiencies and photosynthesis.

Made available in DSpace on 2021-06-25T10:17:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-02-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) There are conclusive evidences of selenium (Se) deficiency in Brazilian soils and foods. Brazil is the largest producer and consumer of coffee worldwide, which favors agronomic biofortification of its coffee. This study aimed to evaluate effects of foliar application of three formulations and six rates of Se on antioxidant metabolism, agronomic biofortification and yield of coffee beans. Seven Se concentrations (0, 10, 20, 40, 80, 100 and 160 mg L−1) were applied from three formulations of Se (sodium selenate, nano-Se 1500, and nano-Se 5000). Selenium application up to 40 mg L−1 increased the concentration of photosynthetic pigments such as chlorophylls, pheophytins and carotenoids in coffee leaves. Foliar application of Se ranging from 20 to 80 mg L−1 decreased lipid peroxidation and concentration of hydrogen peroxide, but increased superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase activities in coffee leaves. These results indicated that foliar Se application stimulates antioxidative metabolism to mitigate reactive oxygen species. Foliar application of 20 mg Se L−1 of sodium selenate increased coffee yield by 38%, and 160 mg Se L−1 of nano-Se 5000 increased dramatically coffee yield by 42%. Selenium concentration in grains ranged from 0.116 to 4.47 mg kg−1 (sodium selenate), 4.84 mg kg−1 (nano-Se 1500) and 5.82 mg kg−1 (nano-Se 5000). The results suggest the beneficial effect of Se on the increment of photosynthetic pigments, antioxidative metabolism, increased coffee yield and nutritional quality of grains. The recommended foliar Se application in this study can mitigate abiotic stressors such as high temperatures resulting in higher yield of coffee plants. São Paulo State University (UNESP) Federal Institute of Mato Grosso do Sul (IFMS), MS – 473, km 23 São Paulo State University (UNESP) School of Sciences and Engineering São Paulo State University (UNESP) São Paulo State University (UNESP) School of Sciences and Engineering CAPES: 001 CNPq: 309380/2017-0

Made available in DSpace on 2020-12-12T02:04:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Cadmium (Cd) is probably the most damaging metal to plant species; with a long biological half-life, it can be taken up by plants, disrupting the cell homeostasis and triggering several metabolic pathways. Selenium (Se) improves plant defence systems against stressful conditions, but the biochemical antioxidant responses to Cd stress in tomato plants is poorly understood. To further address the relationship of Cd-stress responses with Se mineral uptake, Cd and Se concentration, proline content, MDA and H2O2 production, and the activity of SOD, APX, CAT and GR enzymes were analyzed in Micro-Tom (MT) plants submitted to 0.5 mM Cd. The results revealed different responses according to Se combination and Cd application. For instance, roots and leaves of MT plants treated with Se exhibited an increase in dry mass and nutritional status, exhibited lower proline content and higher APX and GR activities when compared with plants with no Se application. Plants submitted to 0.5 mM Cd, irrespective of Se exposure, exhibited lower proline, MDA and H2O2 content and higher SOD, CAT and GR activities. Selenium may improve tolerance against Cd, which allowed MT plants exhibited less oxidative damage to the cell, even under elevated Cd accumulation in their tissues. The results suggest that Se application is an efficient management technique to alleviate the deleterious effects of Cd-stress, enhancing the nutritional value and activity of ROS-scavenging enzymes in tomato plants. Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias (FCAV) Departamento de Biologia Aplicada à Agropecuária Universidade de São Paulo (USP) Centro de Energia Nuclear na Agricultura (CENA) Laboratório de Nutrição Mineral de Plantas Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias (FCAV) Departamento de Fitossanidade Universidade Estadual Paulista (UNESP) Faculdade de Ciências e Engenharia Laboratório de Biologia Universidade de São Paulo (USP) Escola Superior de Agricultura Luiz de Queiroz (ESALQ) Depto. de Genética Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias (FCAV) Departamento de Biologia Aplicada à Agropecuária Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias (FCAV) Departamento de Fitossanidade Universidade Estadual Paulista (UNESP) Faculdade de Ciências e Engenharia Laboratório de Biologia

Made available in DSpace on 2020-12-12T01:31:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-15 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Selenium (Se) is considered a beneficial element to higher plants based on its regulation of antioxidative system under abiotic or biotic stresses. However, the limit of beneficial and toxic physiological effects of Se is very narrow. In the present study, the antioxidant performance, nutritional composition, long-distance transport of Se, photosynthetic pigments, and growth of Coffea arabica genotypes in response to Se concentration in solution were evaluated. Five Coffea arabica genotypes (Obatã, IPR99, IAC125, IPR100 and Catucaí) were used, which were grown in the absence and presence of Se (0 and 1.0 mmol L−1) in nutrient solution. The application of 1 mmol L−1 Se promoted root browning in all genotypes. There were no visual symptoms of leaf toxicity, but there was a reduction in the concentration of phosphorus and sulfur in the shoots of plants exposed to high Se concentration. Except for genotype Obatã, the coffee seedlings presented strategies for regulating Se uptake by reducing long-distance transport of Se from roots to shoots. The concentrations of total chlorophyll, total pheophytin, and carotenoids were negatively affected in genotypes Obatã, IPR99, and IAC125 upon exposure to Se at 1 mmol L−1. H2O2 production was reduced in genotypes IPR99, IPR100, and IAC125 upon exposure to Se, resulting in lower activity of superoxide dismutase (SOD), and catalase (CAT). These results suggest that antioxidant metabolism was effective in regulating oxidative stress in plants treated with Se. The increase in sucrose, and decrease in SOD, CAT and ascorbate peroxidase (APX) activities, as well as Se compartmentalization in the roots, were the main biochemical and physiological modulatory effects of coffee seedlings under stress conditions due to excess of Se. São Paulo State University (UNESP), Passeio Monção 830 Center for Nuclear Energy in Agriculture (CENA) University of São Paulo (USP), Av. Centenário 303 Federal Institute of Mato Grosso Do Sul (IFMS), MS–473, Km 23 São Paulo State University (UNESP), Rua Domingos da Costa Lopes 780 São Paulo State University (UNESP), Passeio Monção 830 São Paulo State University (UNESP), Rua Domingos da Costa Lopes 780

Made available in DSpace on 2020-12-10T17:27:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-02-26 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Jatropha is an excellent plant model to evaluate physiological responses involving species tolerance to abiotic stresses, such as low calcium (Ca), magnesium (Mg) and sulfur (S) availability. Moreover, Ca, Mg and S are essential for the establishment of this plant in large areas. Better acknowledgment of appropriate nutrient levels can help with proper fertilization. This study aimed to gain insight during initial growth in Jatropha plants deficient in Ca, Mg and S by measuring leaf gas exchange, nutrient uptake efficiency (UpE), nutrient use efficiency (UtE) and biomass partitioning at plant harvest. Chlorophyll, carotenoid concentration, net photosynthesis rate (A), stomatal conductance (g(S)), transpiration (E), leaf-scale intrinsic water use efficiency (IWUE) and instantaneous carboxylation efficiency (k) in leaves of Ca-, Mg- and S-deficient plants revealed imbalances prior to visual symptom appearance. Nutrient deficiencies decreased A, which in turn hindered plant growth and biomass partitioning among leaves, stem and roots. However, S-deficient plants maintained values of UtE (at 120 days after S withdrawal), as well as of A, g(S), E, k and biomass allocation similar to those of control plants, during all evaluation periods. Jatropha was highly and very sensitive to Ca and Mg deficiency, respectively, with all results were dramatically decreased in contrast to the control. In conclusion, early physiological evaluation of Ca and Mg status in starved young plants with contrasting UtE values may be a reliable tool with which to predict early nutritional deficiencies before visual symptom appearance. Univ Sao Paulo, Ctr Nucl Energy Agr, Ave Centenario 303 CP 96, BR-13416000 Piracicaba, Brazil Univ Sao Paulo, Luiz de Queiroz Coll Agr, Piracicaba, Brazil Sao Paulo State Univ, Fac Ciencias Agr & Vet, Jaboticabal, Brazil Sao Paulo State Univ, Fac Ciencias Agr & Vet, Jaboticabal, Brazil FAPESP: 2011/15208-0 CNPq: 310572/2017-7

The fragmentary information on phosphorus (P) × zinc (Zn) interactions in plants warrants further study, particularly in plants known for their high P and Zn requirements, such as cotton (Gossypium hirsutum L.). The objective of this study was to investigate the effect of P × Zn interactions in a modern cultivar of cotton grown hydroponically. Biomass, mineral nutrition and photosynthetic parameters were monitored in plants receiving contrasting combinations of P and Zn supply. Root biomass, length and surface area were similar in plants with low P and/or low Zn supply to those in plants grown with high P and high Zn supply, reflecting an increased root/shoot biomass quotient when plants lack sufficient P or Zn for growth. Increasing P supply and reducing Zn supply increased shoot P concentrations, whilst shoot Zn concentrations were influenced largely by Zn supply. A balanced P × Zn supply (4 mM P × 4 μM Zn) enabled greatest biomass accumulation, while an imbalanced supply of these nutrients led to Zn deficiency, P toxicity or Zn toxicity. Net photosynthetic rate, stomatal conductance, transpiration rate and instantaneous carboxylation efficiency increased as P or Zn supply increased. Although increasing P supply reduced the P-use efficiency in photosynthesis (PUEP) and increasing Zn supply reduced the Zn-use efficiency in photosynthesis (ZnUEP), increasing Zn supply at a given P supply increased PUEP and increasing P supply at a given Zn supply increased ZnUEP. These results suggest that agricultural management strategies should seek for balanced mineral nutrition to optimize yields and resource-use efficiencies.

Made available in DSpace on 2019-10-04T12:30:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-11-01 Brazilian Federal Government Agency Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Research Foundation Flanders - FWO Exposure to cadmium (Cd) can cause oxidative stress and injuries to the photosynthetic apparatus of plants. Otherwise, plant metabolism impaired by Cd toxicity can be aided by a proper sulfur (S) nutrition, since S is a component of antioxidants and photosynthetic systems. In this sense, our aim in this study was to evaluate the effect of S supply (0.1, 1.9 and 3.7 mmol L-1) on the antioxidant and photosynthetic systems of Massai grass exposed to Cd (0.0, 0.1 and 0.5 mmol L-1) as a prerequisite for studies of Cd phytoextraction. Plants supplied with 3.7 mmol L-1 S showed the lowest growth and the highest Cd concentrations when exposed to 0.5 mmol L-1 Cd. However, Massai grass grown without S deprivation showed the highest GSH + GSSG concentrations in all tissues and the lowest lipid peroxidation in stems and sheaths and roots. In general, the activities of SOD, CAT, APX, GPOX and GR did not increase in Massai grass exposed to Cd, even with proper S supply. Severe Cd exposure halted the photosynthetic system of Massai grass, although well-nourished plants with S exhibited greatest photosynthetic rate probably due to the action of GSH in the control of the oxidative stress. Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13416000 Piracicaba, Brazil Hasselt Univ, Ctr Environm Sci, B-3590 Diepenbeek, Belgium Univ Fed Acre, BR-69920900 Rio Branco, Brazil Univ Sao Paulo, Luiz de Queiroz Coll Agr, BR-13418900 Piracicaba, Brazil Sao Paulo State Univ, BR-17602496 Tupa, Brazil Sao Paulo State Univ, BR-17602496 Tupa, Brazil CAPES: 1332394 FAPESP: 2014/16731-7 FAPESP: 2014/18735-0 FAPESP: 2015/21562-2 FAPESP: 2017/12367-7

Made available in DSpace on 2018-12-11T17:37:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Aluminium (Al) is a toxic element for plants living in soils with acidic pH values, and it causes reductions in the roots and shoots development. High Al concentrations can cause physiological and structural changes, leading to symptoms of toxicity in plant tissue. The aim of this study was to describe the Al toxicity in soybean plants through physiological, nutritional, and ultrastructure analyses. Plants were grown in nutrient solution containing increasing Al concentrations (0; 0.05; 0.1; 1.0, 2.0 and 4.0 mmol L−1). The Al toxicity in the soybean plants was characterized by nutritional, anatomical, physiological, and biochemical analyses. The carbon dioxide assimilation rates and stomatal conductance were not affected by the Al. However, the capacity for internal carbon use decreased, and the transpiration rate increased, resulting in increased root biomass at the lowest Al concentration in the nutrient solution. The soybean plants exposed to the highest Al concentration exhibited lower root and shoot biomass. The nitrate reductase and urease activities decreased with the increasing Al concentration, indicating that nitrogen metabolism was halted. The superoxide dismutase and peroxidase activities increased with the increasing Al availability in the nutrient solution, and they were higher in the roots, showing their role in Al detoxification. Despite presenting external lesions characterized by a damaged root cap, the root xylem and phloem diameters were not affected by the Al. However, the leaf xylem diameter showed ultrastructural alterations under higher Al concentrations in nutrient solution. These results have contributed to our understanding of several physiological, biochemical and histological mechanisms of Al toxicity in soybean plants. São Paulo State University (UNESP), Postal Code 17602-496 São Paulo State University (UNESP), Postal Code 15385-000 São Paulo State University (UNESP), Postal Code 17900-000 University of São Paulo (USP), Postal Code 13416-000 Federal University of Triângulo Mineiro (UFTM), Postal Code 38280-000 Federal University of Parana (UFPR), Postal Code 80060-000 São Paulo State University (UNESP), Postal Code 17602-496 São Paulo State University (UNESP), Postal Code 15385-000 São Paulo State University (UNESP), Postal Code 17900-000 CNPq: 309380/2017-0 CNPq: 448783/2014-2

B-Zn interaction modifies the nutritional dynamics of copper (Cu), iron (Fe) and manganese (Mn) in cotton. The main objective of this research was to evaluate the effect of B and Zn concentrations on the absorption of Cu, Fe and Mn in cotton plants grown in a nutrient solution. A completely randomized experimental design with three replicates was performed, in a 4x5 factorial scheme, corresponding to four concentrations of B (0, 20, 40 and 80 μΜ L-1) and five concentrations of Zn (0, 1, 2, 4 and 8 μΜ L-1). At 115 days after emergence, the plants were collected, divided into roots, shoots and fruits, and chemically analyzed. The results allowed to conclude that the Cu content and total Cu in the fruit, total Cu in the roots, Cu efficiency, Fe content in the roots, Fe absorption efficiency, Mn content in the fruit, and Mn absorption efficiency of cotton are influenced by the concentrations of B in the solution. The interaction between B and Zn affected the total Fe in the roots, Fe content and total Fe content in the fruit, Fe transport efficiency, total Mn in the shoots and Mn transport efficiency. In addition, Zn acts differently according to the supply of B and vice versa. RESUMEN La interacción boro-zinc (B-Zn) modifica la dinámica nutricional del cobre (Cu), hierro (Fe) y manganeso (Mn) en el cultivo del algodón. El objetivo del presente trabajo fue evaluar el efecto de concentraciones de B y Zn sobre la absorción de Cu, Fe y Mn por plantas de algodón creciendo en solución nutritiva. Se utilizó un diseño completamente al azar con tres repeticiones en un esquema factorial 4x5, siendo cuatro las concentraciones de B (0, 20, 40 y 80 μM L-1) y cinco las concentraciones de Zn (0, 1, 2, 4 y 8 μM L-1). A los 115 días después de emergencia las plantas fueron recolectadas, divididas en raíz, parte aérea y frutos, y sometidas a análisis químicos. Los resultados permitieron concluir que el contenido y el total de Cu en el fruto, el contenido de Cu en la raíz, la eficiencia de utilización de Cu, el total de Fe en la raíz, la eficiencia de absorción de Fe, el total de Mn en el fruto y la eficiencia de absorción de Mn son influenciadas por las concentraciones de B en la solución. La interacción B-Zn afectó el contenido de Fe en la raíz, el contenido y el total de Fe en el fruto, eficiencia de transporte de Fe, el total de Mn en la parte aérea y la eficiencia del transporte de Mn, Adicionalmente Zn actúa de manera diferente de acuerdo al suministro de B y viceversa.

The objective of the present study was to evaluate agronomic biofortification with nitrogen (N) and selenium (Se) with the aim of increasing the daily Se intake by the population and the nutritional quality of the grain. A randomized block experimental design with a 5 × 2 factorial scheme was used; the factors were the five levels of N (0, 20, 40, 80, and 120 kg ha−1), applied as topdressing fertilization, and the two levels of Se (0 and 25 g ha−1). The reserve protein fractions in the seeds, glutelin, and globulin increased significantly when Se application was combined with N fertilization. Grain Se content varied from 0.03 to 0.35 mg kg−1, which was within the food safety limit of 0.3 mg kg−1 established by the Codex Alimentarius. The estimated daily Se intake originating from Se-biofortified rice varied between 2.05 and 24.7 μg per day, representing an increase from 3.72% to 44.9% of the daily Se requirement. Because the recommended Se daily intake for adults is 55 μg per day, the present study presents relevant information about agronomic biofortification to increase Se concentrations in edible plant parts, with possible benefits to human health.

Made available in DSpace on 2018-12-11T17:36:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-12-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Nickel (Ni) toxicity has been reported to decrease productivity in soybean (Glycine max L.). However, soybean responses to Ni toxicity are not well understood. The aim of the present study was to describe Ni toxicity in soybean plants through physiological, nutritional, and ultrastructural analyses. Plants were grown in nutrient solution containing increasing Ni concentrations (0, 0.05, 0.1, 0.5, 10, and 20 μmol L−1), and nutritional, anatomical, physiological and biochemical features were determined. The results revealed previously unreported detrimental effects of Ni toxicity on soybean plants. CO2 assimilation rates, stomatal conductance and transpiration decreased, resulting in lower biomass in soybean plants exposed to the highest Ni levels. Nitrate reductase activity increased with up to 0.05 μmol L−1 Ni and then decreased, indicating halted N-metabolism. Urease activity increased with increasing Ni availability in the nutrient solution, and peroxidase and superoxide dismutase activities were higher in plants grown at higher Ni levels. Leaf epidermal thickness (abaxial and adaxial), as well as root xylem and phloem diameter, decreased starting at 0.1 μmol L−1 Ni. Mean Ni concentrations varied from 77.5 to 17,797.4 mg kg−1 in roots and 2.3 to 16,774.5 mg kg−1 in shoots. Soybean plants exhibited symptoms of Ni toxicity starting at 0.1 μmol L−1 Ni, presenting mean shoot Ni concentration of 28.9 mg kg−1, along with leaf water loss until complete drying. The results contribute to our understanding of several physiological, biochemical and histological mechanisms of Ni toxicity in soybean, which is still poorly understood. São Paulo State University - UNESP Federal University of Mato Grosso do Sul - UFMS University of São Paulo - USP São Paulo State University − UNESP São Paulo State University - UNESP São Paulo State University − UNESP CNPq: 448783/2014-2

Made available in DSpace on 2020-12-12T01:13:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-30 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) BACKGROUND: Selenium (Se) is an essential element for humans and animals. Rice is one of the most commonly consumed cereals in the world, so the agronomic biofortification of cereals with Se may be a good strategy to increase the levels of daily intake of Se by the population. This study evaluated the agronomic biofortification of rice genotypes with Se and its effects on grain nutritional quality. Five rates of Se (0, 10, 25, 50, and 100 g ha−1) were applied as selenate via the soil to three rice genotypes under field conditions. RESULTS: Selenium concentrations in the leaves and polished grains increased linearly in response to Se application rates. A highly significant correlation was observed between the Se rates and the Se concentration in the leaves and grains, indicating high translocation of Se. The application of Se also increased the concentration of albumin, globulin, prolamin, and glutelin in polished grains. CONCLUSION: Biofortifying rice genotypes using 25 g Se ha−1 could increase the average daily Se intake from 4.64 to 66 μg day−1. Considering that the recommended daily intake of Se by adults is 55 μg day−1, this agronomic strategy could contribute to alleviating widespread Se malnutrition. © 2019 Society of Chemical Industry. São Paulo State University (UNESP) University of São Paulo (USP) School of Biosciences University of Nottingham The James Hutton Institute São Paulo State University (UNESP) FAPESP: 15/11690-3 CNPq: 309380/2017-0

A demanda crescente por alimentos e as preocupações ambientais fizeram com que líderes governamentais incentivassem a adoção de tecnologias que possam aumentar a oferta de alimentos de forma sustentável. O objetivo com esse trabalho é valorar a mitigação de gases de efeito estufa através da recuperação de pastagem por meio do financiamento com a linha de crédito do Programa Agricultura de Baixa Emissão de Carbono, utilizando a ferramenta custo marginal de abatimento. Para alcançar os objetivos propostos, foram utilizados dados financeiros do Centro de Estudos Avançados em Economia Aplicada e da Confederação da Agricultura e Pecuária do Brasil e de emissões, do Painel Intergovernamental sobre Mudanças Climáticas e do Plano Agricultura de Baixa Emissão de Carbono para simular os custos anuais líquidos e as emissões líquidas da tecnologia atual e de abatimento, representadas por uma pecuária de baixa tecnologia e em pastagem recuperada, respectivamente. Os valores financeiros e de emissões da pecuária em pasto recuperado se apresentaram mais favoráveis quando comparados à pecuária de baixa tecnologia. Considerando esses dois fatores, chega-se a um custo marginal de abatimento de - R$ 24,72 por tCO2 equivalente. Desta maneira, a cada uma tonelada de gás carbônico equivalente mitigado pela recuperação da pastagem, o pecuarista tem um resultado financeiro de R$ 24,72 a mais do que se continuasse com uma pecuária de baixa tecnologia. Sendo assim, a recuperação de pastagem demostra ser uma prática que permite o aumento na produção de alimento de forma sustentável tanto ambientalmente quanto financeiramente. = Due to the growing demand for food and environmental concerns, government leaders have been driven to encourage the adoption of technologies which can increase the food supply in a sustainable way. This work aims to value greenhouse gas mitigation through pasture recovery by market incentives such as financing with the Low Carbon Agriculture Program credit line, using the marginal abatement cost tool. To achieve the proposed goals, financial data from the Center for Advanced Studies in Applied Economics and the Brazilian Confederation of Agriculture and Livestock was used, as well as emissions data from the Intergovernmental Panel on Climate Change and Low Carbon Agriculture Plan in order to simulate an annual net costs and net emissions of current and abatement technologies, represented respectively by a low-tech livestock and a livestock in recovered pasture. The financial and emissions figures of a livestock in a recovered pasture were more favorable in comparison to low-tech livestock. Taking into consideration these two factors, the marginal abatement cost is - R$ 24.72 per tCO2 equivalent. In other words, for each ton of equivalent carbon dioxide mitigated by pasture recovery, the farmer has a financial gain of R$ 24.72 than keeping low-tech livestock. Thus, from a financial and environmental perspective, pasture recovery has shown to be a practice which allows a sustainable increase in food production.

Nickel availability in the soil is altered mainly by pH, which can indirectly be changed by base saturation (BS). The objective was to evaluate the effect of consecutive plants growth on Ni availability and enzymatic activities in the rhizosphere. It was evaluated the interaction between BS ratios (50% and 70%) and Ni application rates (0, 0.1, 0.5, 1.0, and 10.0 mg dm−3 of soil) on the availability of Ni in the rhizosphere. Two agricultural crops were grown in succession (soybean and sunflower). The effects of Ni rates and BS ratios on the activity of the urease and dehydrogenase in the soil were evaluated. Ni distribution in the bulk soil fractions was also investigated by Ni sequential extraction. The objective was to evaluate the effect of consecutive plants growth on Ni availability and enzymatic activities in the rhizosphere. It was observed the Ni availability was higher in the rhizosphere than bulk soil. The plant species have a large influence on the enzymatic activities in the rhizosphere. Urease activity was higher in the rhizosphere with BS70 under soybean growth, whereas for sunflower, BS50 lead to the highest urease activity, in all rates. The dehydrogenase activity was greater with BS70, regardless of plant species. The extractants Mehlich-1, Mehlich-3, and diethylenetriamine penta acetic acid (DTPA) showed comparable ability to estimate the available Ni fraction in the rhizosphere with a significant correlation with Ni accumulation in the grains. The Ni sequential extraction results showed the predominant effect of pH on the availability of Ni in bulk soil. Ni bound to organic matter (OM) was the fraction that showed the greatest BS influence. In soil under BS50, up to 20% of total Ni in the soil was bound to OM. Increasing Ni application rates to the soil increased the exchangeable fraction of Ni in the bulk soil up to 36-fold, but did not cause toxicity for either crops. Collectively, the results showed that nickel availability in rhizosphere affected urease and dehydrogenase activities, Ni uptake, and plant growth-related responses to different extents. Our work suggests that the rhizosphere should be evaluated for Ni monitoring in Ni-supplied agricultural areas.

Made available in DSpace on 2018-12-11T17:18:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-06-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Selenium (Se) is considered a beneficial element for plants; however, in high concentrations, it causes negative effects on plant physiology and development. This study reports the first physiological, nutritional, and ultrastructural description of Se toxicity in cowpea growing under field conditions. Selenium was supplied as a foliar application of sodium selenite at varying concentrations (0, 50, 100, 200, 400, 800, 1200, and 1600 g ha−1). An increased yield was observed with the application of 50 g ha−1 Se. Application of concentrations higher than 50 g ha−1 caused leaf toxicity. Increased lipid peroxidation and hydrogen peroxide concentration and reduced total sugars, sucrose, and carotenoid concentration were observed at highest doses tested (1200 and 1600 g ha−1). Applications of more than 50 g ha−1 Se reduced the phloem diameter, caused chlorosis of the leaf blade with a coalescence of lesions, and caused pink salt deposits to appear. Lesions were observed mainly near the trichomes on the adaxial surface of the leaf blade. An analysis of the element distribution with microprobe X-ray fluorescence spectrometry (μ-XRF) revealed accumulation of Se, calcium (Ca), potassium (K), copper (Cu), and manganese (Mn) near the primary vein and in the necrotic brown areas of the leaf lesions. In contrast, Na was homogeneously distributed in the leaf tissue. São Paulo State University – UNESP, Ilha Solteira, Postal Code 15.385-000 São Paulo State University – UNESP, Tupã Postal Code 17602-496, SP University of São Paulo – USP, Postal Code 13416-000, SP The James Hutton Institute, Invergowrie School of Biosciences The University of Nottingham, Sutton Bonington São Paulo State University – UNESP, Ilha Solteira, Postal Code 15.385-000 São Paulo State University – UNESP, Tupã Postal Code 17602-496, SP FAPESP: 2015/19121-8 FAPESP: 2016/19773-8

The efficient production of cotton in soils with low levels of phosphorus (P) require a better understanding of the interference of plant adaptations in relation to P stress, about the absorption, transport and use of other nutrients such as nitrogen (N). Thus, the selection of genotypes efficient in the use of N in low P supply conditions is an effective tool for proper plant development. Hear, was to evaluate the nitrogen use efficiency in Gossypium barbadense L. genotypes grown in an adequate and low phosphorus availability conditions. For that were tested 14 genotypes of pima cotton, grown in two level of P supply: adequate and low level. We evaluated the concentration and accumulation of N, as well as the N efficiency of absorption, transport and use. The genotypes grown under low P supply showed higher leaf N, indicating clear synergistic relationship between N and P. The MT 92 genotype showed a higher capacity to absorb and transport of N in low P supply in the soil conditions. The MT 105 genotype showed higher capacity of conversion N in biomass. The genotypes studied were characterized as a source of genes for adaptation to low P availability for the use of N, are indicated for genetic improvement in the cotton crop (Gossypium hirsutun L).

Jatropha seeds oil can replace fossil fuels, but the nutrient supply management for this species is not fully described. The objective with this work was to establish curves of macronutrient (nitrogen - N; phosphorus - P; potassium - K; calcium - Ca; magnesium - Mg and sulfur - S) content in leaves, stem and roots, and to evaluate the relative growth rate (RGR), absolute growth rate (AGR) and the foliar mass ratio (FMR). The experiment was arranged in completely randomized design with five replications. Jatropha plants were grown in nutrient solution and collected at intervals of 14 up to 119 days after treatments started. The period of highest uptake of nutrients occurred from 7 to 35 days after treatments started, which coincides with highest AGR, RGR, FMR and accumulation of dry biomass. The highest Ca and Mg accumulation occurred in the leaves (respectively 48% and 47% of the total taken up), while N, K, S and P were mostly accumulated in the stem (58%, 56%, 56% and 53%, respectively). The nutrients more taken up by Jatropha plants were N and Ca, and the order of macronutrients uptake was: N > Ca > K > Mg > S > P. Jatropha plants have shown high macronutrients content on its early development, indicating the importance of nutritional management to achieve reliable biomass yield. RESUMO O óleo das sementes de pinhão-manso possui potencial para substituir combustíveis fósseis, porém o manejo nutricional para a espécie ainda não é totalmente descrito. O objetivo com esse trabalho foi estabelecer curvas de acumulo de macronutrientes em folhas, caule e raiz, bem como avaliar a taxa de crescimento relativo (TCR), taxa de crescimento absoluto (TCA) e relação de massa foliar (RMF) do pinhão-manso. O experimento foi inteiramente casualizado com cinco repetições. Plantas de pinhão-manso foram cultivadas em solução nutritiva e coletadas em intervalos de 14 dias até 119 após o início do tratamento. O período de maior absorção de macronutrientes ocorreu entre 7 a 35 dias após o início dos tratamentos, que coincidiu com a maior TCR, TCA, RMF e acúmulo de biomassa seca. O maior conteúdo de Ca e Mg ocorreu nas folhas (respectivamente 48% e 47% do total absorvido), enquanto N, K, S e P foram mais acumulados no caule (58%, 56%, 56% e 53%, respectivamente). Os nutrientes mais absorvidos pelo pinhão-manso foram N e Ca, e a ordem de conteúdo de macronutrientes foi: N > Ca > K > Mg > S > P. O pinhão-manso apresentou alto acúmulo de macronutrientes no seu desenvolvimento inicial, indicando a importância do manejo nutricional para alcançar a produção adequada.

Made available in DSpace on 2018-12-11T17:32:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-06-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The description of physiological disorders in physic nut plants deficient in nitrogen (N), phosphorus (P) and potassium (K) may help to predict nutritional imbalances before the appearance of visual symptoms and to guide strategies for early nutrient supply. The aim of this study was to evaluate the growth of physic nuts (Jatropha curcas L.) during initial development by analyzing the gas exchange parameters, nutrient uptake and use efficiency, as well as the nitrate reductase and acid phosphatase activities and polyamine content. Plants were grown in a complete nutrient solution and solutions from which N, P or K was omitted. The nitrate reductase activity, phosphatase acid activity, polyamine content and gas exchange parameters from leaves of N, P and K-deficient plants indicates earlier imbalances before the appearance of visual symptoms. Nutrient deficiencies resulted in reduced plant growth, although P- and K-deficient plants retained normal net photosynthesis (A), stomatal conductance (gs) and instantaneous carboxylation efficiency (k) during the first evaluation periods, as modulated by the P and K use efficiencies. Increased phosphatase acid activity in P-deficient plants may also contribute to the P use efficiency and to A and gs during the first evaluations. Early physiological and biochemical evaluations of N-, P- and K-starved plants may rely on reliable, useful methods to predict early nutritional imbalances. USP – University of São Paulo Center for Nuclear Energy in Agriculture UNESP – São Paulo State University UNESP – São Paulo State University FAPESP: 2011/15208-0

Selenium (Se) is an essential micronutrient for human and animal healthy due to its capabilities to support antioxidant defence systems. However, problems related to the deficiency of Se are emerging issue for human health worldwide and plant species differ considerably in their susceptibility to high concentrations of Se, and certain plant species can be able to accumulate Se to astonishingly high concentrations. Many factors can affect the content of Se in different foods, including different uptake rate by plants, which can be related to plant type, soil, pH, microbial activity, rainfall and a number of other biogeochemical parameters. Humans Se intake and Se status in the population depends firstly on Se concentrations in soils, and hence the Se concentrations in the harvested edible plants in these soils. Thus, this chapter aims to compile some information about research work on essentiality of Se for humans and other mammals, and the need for a sufficient daily Se intake.

Resumen pt: Muitas especies e mesmo variedades de plantas, diferem em suas respostas quanto a disponibilidade de nutrientes no meio de cultivo, cujas causas residem ...

Made available in DSpace on 2018-12-11T16:45:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-04-01 Manganese (Mn) is an essential element for plants; however, high concentrations in certain soil conditions can cause toxicity symptoms in the plant tissue. Here, we describe Mn toxicity symptoms and Mn toxicity responses in soybean plants. Soybean plants exposed to excess Mn showed reductions in the CO2 assimilation rate and stomatal conductance, which in turn resulted in decreased shoot biomass. Furthermore, peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity were higher in plants grown with the highest Mn concentration. The Mn doses increased the activity of antioxidant enzymes such as CAT, POD, and SOD. The toxicity symptoms presented by the leaves included hypertrophying of the adaxial epidermis and the formation of necrotic areas with purple-colored veins. Dramatic movement of calcium from the healthy region to the purple-colored necrotic region was observed, as was the exit of potassium from the necrotic area to the healthy region of the tissue. The high activities of POD and SOD in the presence of high Mn compartmented in the roots was the main physiological responses at high Mn uptake by soybean plants. USP – University of São Paulo Center for Nuclear Energy in Agriculture UNESP – São Paulo State University UNESP – São Paulo State University

Nickel (Ni) availability in soil varies as a function of pH. Plants require Ni in small quantities for normal development, especially in legumes due its role in nitrogen (N) metabolism. This study investigated the effect of soil base saturation, and Ni amendments on Ni uptake, nitrogen (N) accumulation in the leaves and grains, as well as to evaluate organic acids changes in soybean. In addition, two N assimilation enzymes were assayed: nitrate reductase (NR) and Ni-dependent urease. Soybean plants inoculated with Bradyrhizobium japonicum were cultivated in soil-filled pots under two base-cation saturation (BCS) ratios (50 and 70%) and five Ni rates - 0.0; 0.1; 0.5; 1.0; and 10.0 mg dm-3 Ni. At flowering (R1 developmental stage), plants for each condition were evaluated for organic acids (oxalic, malonic, succinic, malic, tartaric, fumaric, oxaloacetic, citric and lactic) levels as well as the activities of urease and nitrate reductase. At the end of the growth period (R7 developmental stage - grain maturity), grain N and Ni accumulations were determined. The available soil-Ni in rhizosphere extracted by DTPA increased with Ni rates, notably in BCS50. The highest concentrations of organic acid and N occurred in BCS70 and 0.5 mg dm-3 of Ni. There were no significant differences for urease activity taken on plants grown at BSC50 for Ni rates, except for the control treatment, while plants cultivated at soil BCS70 increased the urease activity up to 0.5 mg dm-3 of Ni. In addition, the highest values for urease activities were reached from the 0.5 mg dm-3 of Ni rate for both BCS treatments. The NR activity was not affected by any treatment indicating good biological nitrogen fixation (BNF) for all plants. The reddish color of the nodules increased with Ni rates in both BCS50 and 70, also confirms the good BNF due to Ni availability. The optimal development of soybean occurs in BCS70, but requires an extra Ni supply for the production of organic acids and for increased N- shoot and grain accumulation.

In the Brazilian Cerrado, P deficiency restricts cotton production, which requires large amounts of phosphate fertilizer. To improve the yield of cotton crops, genotypes with high P use efficiency must be identified and used. The present study evaluated P uptake and use efficiency of different Gossypium barbadense L. genotypes grown in the Cerrado. The experiment was carried out in a greenhouse with a completely randomized design, 15 x 2 factorial treatment structure (15 genotypes x 2 P levels), and four replicates. The genotypes were MT 69, MT 70, MT 87, MT 91, MT 92, MT 94, MT 101, MT 102, MT 103, MT 105, MT 106, MT 110, MT 112, MT 124, and MT 125; P levels were sufficient (1000 mg pot-1, PS treatment) or deficient (PD treatment). Dry matter (DM) and P levels were determined in cotton plant parts and used to calculate plant P content and use efficiency. In general, DM and P content were higher in the PS than in the PD treatment, with the exception of root DM and total DM in some genotypes. Genotypes also differed in terms of P uptake and use capacity. In the PS treatment, genotypes MT 92 and MT 102 had the highest response to phosphate fertilization. Genotype MT 69 exhibited the most efficient P uptake in the PD treatment. Genotype MT 124 showed the best shoot physiological efficiency, apparent recovery efficiency, and utilization efficiency, whereas MT 110 exhibited the highest root physiological efficiency.

Existem diversos métodos para a interpretação da diagnose foliar; o nível crítico ou as faixas de suficiência descritas na literatura são os mais utilizados. Porém, o uso de métodos de determinação de faixas normais de nutrientes que contemplam regiões específicas (localidades) aumenta a eficiência da interpretação. O objetivo deste trabalho foi determinar as faixas normais de nutrientes para a cultura da cana-de-açúcar, mediante a utilização dos métodos Chance Matemática (ChM), Sistema Integrado de Diagnose e Recomendação (DRIS) e Diagnose da Composição Nutricional (CND), além do Nível Crítico determinado pelo método de distribuição normal reduzida. O trabalho foi realizado tomando-se como base dados relativos a teores de nutrientes em amostras foliares e de produtividade de lavouras comerciais de cana-de-açúcar, localizadas no município de Campos de Goytacazes, RJ. Com o método da ChM, foram obtidas faixas de suficiência semelhantes aos métodos DRIS e CND, para N, Ca, S e Mn, enquanto para P, K, Mg, Cu e Zn os valores obtidos pela ChM foram superiores. A utilização dos métodos ChM, DRIS e CND, em lavouras comerciais de cana-de-açúcar em geral, possibilitou a obtenção de menor amplitude da faixa normal dos nutrientes, em comparação com os valores alcançados pelos métodos nível crítico e faixa de suficiência.

Few studies in Brazil have addressed the need for micronutrients of physic nut focusing on physiological responses, especially in terms of photosynthesis. The objective of this study was to evaluate the effects of omission of boron (B), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) on Jatropha curcas L.. The experimental design was a randomized block with four replications. The treatments were complete solution (control) and solution without B, Cu, Fe, Mn, and Zn. We evaluated the chlorophyll content (SPAD units), photosynthetic rate, dry matter production and accumulation of micronutrients in plants, resulting from different treatments. The first signs of deficiency were observed for Fe and B, followed by Mn and Zn, while no symptoms were observed for Cu deficiency. The micronutrient omission reduced the dry matter yield, chlorophyll content and photosynthetic rate of the plants differently for each omitted nutrient. It was, however, the omission of Fe that most affected the development of this species in all parameters evaluated. The treatments negatively affected the chlorophyll content, evaluated in SPAD units, and the photosynthetic rate, except for the omission of B. However this result was probably due to the concentration effect, since there was a significant reduction in the dry matter production of B-deficient plants. São poucos os estudos brasileiros que contemplam a avaliação nutricional de micronutrientes em pinhão-manso, enfocando respostas fisiológicas, especialmente em termos de fotossíntese. Objetivou-se com este trabalho avaliar os efeitos das omissões de boro (B), cobre (Cu), ferro (Fe), manganês (Mn) e de zinco (Zn), nas respostas fisiológicas do Jatropha curcas L.. O delineamento experimental foi em blocos ao acaso com quatro repetições. Os tratamentos das omissões de micronutrientes foram: solução completa (controle) e omissão individual de B, Cu, Fe, Mn, e de Zn. Foram avaliados o teor de clorofila, em unidades SPAD, a taxa fotossintética, a produção de matéria seca e os acúmulos dos micronutrientes nas plantas, em razão dos tratamentos. As primeiras manifestações de deficiência foram observadas para o Fe e B, seguidas das de Mn e Zn; contudo, não foram observados sintomas de carência de Cu. A omissão de micronutrientes reduziu a produção de matéria seca, os teores de clorofila e a taxa fotossintética do pinhão-manso, de forma diferente para cada omissão. Porém, a omissão de Fe foi a que mais limitou o desenvolvimento dessa espécie em todos os parâmetros avaliados. Os tratamentos influenciaram negativamente os teores de clorofila, avaliados em unidades SPAD, e a taxa fotossintética, exceto para a omissão de B. Entretanto, esse resultado deveu-se, provavelmente, pelo efeito de concentração, visto que houve redução significativa na produção de matéria seca das plantas deficientes em B.