Improving production efficiency is a major challenge for modern orchard systems. The primary response in horticulture is to develop high-density orchard systems that use dwarfing rootstocks and intense management strategies to maintain small tree size. As development and evaluation of novel orchard systems may help improve understanding of plant physiology for the development of high-density systems. The effect of tree size and architecture on physiological and production efficiency was evaluated for tart cherry (Prunus cerasus, P. mahaleb) and apple (Malus spp.) orchard systems using a physiologically driven modeling approach, called allometry. Branch dimensions, canopy dimensions and biomass were measured for 24-year-old tart cherry individuals and 10-year-old 'Golden Delicious' apple individuals on various rootstocks in experimental blocks at the Kaysville Research Farm in Davis Co., Utah. Tree size was related to annual fruit biomass that had been collected over the duration of the apple trial. Branch dimensions, canopy dimensions, yield, and fruit quality were collected in commercial tart cherry orchards of Utah Co. Tree size, architecture, and biomass of tart cherry and apple expressed strong allometric relationships that were broadly consistent among the two orchard tree species and the theoretical expectations derived from wild plants. The most consistent relationship was the trunk diameter (or trunk cross sectional area) - stem biomass relationship, which broadly followed the 8/3-power law. Branch and canopy dimensions that include a measure of length, such as branch length and canopy height, demonstrated architecture indicative of high water efficiency and metabolic activity that is relieved from biomechanical constrains of weight bearing. The apple rootstocks differed from each other in production efficiency with individuals that express smaller branch and canopy dimensions producing a higher proportion of fruit relative to tree size. In the commercial tart cherry orchards, smaller individuals with relatively higher canopy height and spread expressed higher yield and fruit quality. Overall, this research supported the continued development of training systems that maintain small trees to improve physiological and production efficiency. Further research must reconcile other consequences of intense management and overproduction that arise with the increased efficiency facilitated by small tree size and high-density orchard systems to maintain sustainable fruit production.

<p>   </p> <p>Biochar and charcoal cannot properly be discussed without understanding the diverse technologies available for their production. This is because approximately 70% of wood harvested worldwide is burned for energy and this, in addition to unstainable agricultural activities, has caused a massive increase in deforestation and contributed to climate change. Due to this, current global interventions are focused on promoting sustainable approaches through the expansion of agricultural technologies in countries where the deforestation rate keeps increasing due to overdependency on unsustainable and inefficient conversion technologies. It is therefore obvious that African regions cannot be left out when talking about the impact of global agriculture and charcoal production. Not only is 95% of all household energy used in Africa derived from burning wood in the form of charcoal and firewood, but sub-Saharan Africa regions also contribute 62% to global charcoal production. Since sustainability approaches are of global concern and must be understood from different perspectives and regions, this work analyzed sustainable agriculture and climate mitigation strategies using charcoal and biochar production as indicators. From a sustainability point of view, the study categorized this assessment into three chapters to help understand the preferences of local producers in relation to technologies used and the necessary actions or interventions needed for future improvements.</p> <p><br></p> <p>In the first chapter, 492 charcoal producers from Ghana were interviewed with semi-structured questionnaires to understand the demographics of charcoal producers, species used for charcoal, and how these producers intend to sustain the charcoal industry in terms of acquisition of wood resources/raw materials. This helped to analyze how the demographics of charcoal producers influence the charcoal production industry, characterize some wood species suitable and acceptable for sustainable charcoal production, and to recommend some necessary interventions toward sustainability.</p> <p><br></p> <p>In the second chapter, the heating characteristics of the most common indigenous species and exotic species identified in the first chapter were examined for their charcoal production properties (yield and calorific values) using the most common conversion technology available in the study area (earth mound). The heating/calorific values of these species were also determined using a ballistic bomb calorimeter. This also helped in examining the impact of the common charcoal production technologies on the qualities of charcoal produced and their corresponding impacts on the environment. Additionally, this chapter identified that most charcoal production species have longer rotation times with added values other than being used for charcoal. Furthermore, inappropriate conversion technologies minimize charcoal yield and quality; therefore, developing more efficient and affordable conversion kilns would increase charcoal production efficiency and improve the sustainable production of charcoal.</p> <p><br></p> <p>Based on the recommendation from chapter two, chapter three focused on building transferable skills and knowledge to help smallholder farmers and charcoal producers to fabricate cost-effective retorts/kilns for biochar and charcoal production. Through the process, we reviewed, selected, redesigned, and manufactured three common global conversion technologies and tested their potential for sustainable biochar and charcoal production using wood and crop stubbles (corn husk, corn cob, and sorghum residues). This helped in proposing best techniques and technologies suitable for biochar and charcoal production based on their production and use variables. It was therefore concluded that when farmers gain more knowledge and skills in manufacturing relevant and cheap technologies at their convenience, they could make the right subsequent choices towards sustainable agricultural practices.</p> <p>  </p>

É restrito o número de cultivares utilizado nos pomares comerciais, embora a diversidade de gêneros, espécies, cultivares e clones de citros seja grande. No entanto, o processamento industrial baseia-se em quatro cultivares principais, a Hamlin, como precoce, a Pêra como meia estação e a Natal e Valência como tardias. Alicerçada nestas quatro cultivares, o processamento industrial de sucos utiliza-se de frutos de junho a dezembro, com maior intensidade, e até fevereiro do ano seguinte quando a oferta diminui, sendo março a maio o período da entressafra. Por esse motivo, é de extrema importância selecionar cultivares que produzam nesse período. O objetivo, este trabalho foi avaliar o desempenho horticultural de doze cultivares de laranja doce de maturação precoce e identificar aquelas superiores à laranja Hamlin, com intuito de oferecer ao citricultor da região sudoeste do Estado de São Paulo, novas opções que produzam frutos de qualidade, tanto para fruta in natura como para processamento industrial e que tenham produção antecipada. As cultivares avaliadas foram Hamlin (cultivar precoce padrão), Westin, Pineapple, Rubi, Seleta Vermelha, Mayorca, Valência 2, Olivelands, Kawatta, IAPAR 73, Salustiana e Valência Americana. O delineamento experimental foi o inteiramente casualizado, com quatro repetições, compostas por três plantas de cada cultivar. Os dados referentes ao crescimento vegetativo (altura, diâmetro de planta e volume de copa), produção e eficiência produtiva, morfologia dos frutos (massa, largura, comprimento, tamanho, espessura da casca e número de sementes) e características de qualidade interna dos frutos (SST, acidez, porcentagem de suco, ratio, índice tecnológico, ácido ascórbico, índices de cor da polpa e da casca) foram coletados. As médias foram comparadas com a cultivar padrão Hamlin e analisadas pelo teste Dunnett. Para avaliar simultaneamente as características, foram aferidos os índices de desempenho para identificar cultivares promissoras que atendessem aos requisitos tanto para o processamento industrial como para o consumo in natura. Oliverlands foi a cultivar de laranja doce que registrou maior altura de planta e volume de copa, maior produção de frutos e maior eficiência produtiva em relação a cultivar Hamlin. Para o processamento industrial, a laranja Westin apresentou alto índice de desempenho enquanto que as laranjas Valência 2 e Salustiana registraram índices de desempenho favoráveis para consumo in natura. Não foram observados cultivares de laranja doce com dupla aptidão para o processamento industrial e consumo in natura na região sudoeste do Estado de São Paulo. / The number of sweet orange cultivars used in commercial orchards in Brazil is restricted, although the diversity of genera, species, cultivars and clones of citrus is great. However, the industrial processing is based on four main cultivars, the \'Hamlin\', as early maturing, the \'Pera\', as mid-season, and \'Natal\' and \'Valencia\' as late maturing cultivars. Anchored on these four cultivars, the orange juice industry processes fruits from June through December with greater intensity, January and February with lower supply, and the period from March through May is considered off season. Therefore, it is extremely important to select varieties that produce during this period. The objective of this study was to evaluate the horticultural performance of twelve early maturing sweet orange cultivars and identify those better than the \'Hamlin\' sweet orange, aiming to offer new options for producing fruits with quality, as for fresh fruit market as for industrial utilization, during early citrus harvest season in the southwest region of São Paulo state. The cultivars \'Hamlin\' (early maturing standard cultivar), \'Westin\', \'Pineapple\', \'Ruby\', \'Seleta Vermelha\', \'Mayorca\', \'Valencia 2\', \'Oliverlands\', \'Kawatta\', \'IAPAR 73\', \'Salustiana\' and \'Valencia Americana\' were evaluated. The experimental design was completely randomized with four replications, consisting of three plants of each cultivar per plot. Data concerning vegetative growth (plant height, stem diameter and canopy volume), production and yield efficiency, fruit morphology (mass, width, length, size, shell thickness and number of seeds) and the characteristics of internal fruit quality (total soluble solids, acidity, percentage of juice, \"ratio\", technological index, ascorbic acid, color indexes of pulp and peel) were collected The averages were compared to \'Hamlin\' sweet orange (standard cultivar) and analyzed by Dunnett test. To evaluate the characteristics simultaneously, performance indexes were estimated for identifying promising cultivars for utilization as for juice industry as for consumption fresh fruit market. \'Oliverlands\' was the sweet orange cultivar which showed higher plant height and plant volume, higher production and yield efficiency as compared to \'Hamlin\' sweet orange. The cultivar \'Westin\' showed higher performance index for the industrialization process, whereas \'Valencia 2\' and \'Salustiana\' sweet oranges had adequate performance indexes for fresh fruit market. There was no cultivar of sweet orange that had the simultaneous ability for the juice industry and for fresh fruit market in the southwestern region of Sao Paulo state.

É restrito o número de cultivares utilizado nos pomares comerciais, embora a diversidade de gêneros, espécies, cultivares e clones de citros seja grande. No entanto, o processamento industrial baseia-se em quatro cultivares principais, a Hamlin, como precoce, a Pêra como meia estação e a Natal e Valência como tardias. Alicerçada nestas quatro cultivares, o processamento industrial de sucos utiliza-se de frutos de junho a dezembro, com maior intensidade, e até fevereiro do ano seguinte quando a oferta diminui, sendo março a maio o período da entressafra. Por esse motivo, é de extrema importância selecionar cultivares que produzam nesse período. O objetivo, este trabalho foi avaliar o desempenho horticultural de doze cultivares de laranja doce de maturação precoce e identificar aquelas superiores à laranja Hamlin, com intuito de oferecer ao citricultor da região sudoeste do Estado de São Paulo, novas opções que produzam frutos de qualidade, tanto para fruta in natura como para processamento industrial e que tenham produção antecipada. As cultivares avaliadas foram Hamlin (cultivar precoce padrão), Westin, Pineapple, Rubi, Seleta Vermelha, Mayorca, Valência 2, Olivelands, Kawatta, IAPAR 73, Salustiana e Valência Americana. O delineamento experimental foi o inteiramente casualizado, com quatro repetições, compostas por três plantas de cada cultivar. Os dados referentes ao crescimento vegetativo (altura, diâmetro de planta e volume de copa), produção e eficiência produtiva, morfologia dos frutos (massa, largura, comprimento, tamanho, espessura da casca e número de sementes) e características de qualidade interna dos frutos (SST, acidez, porcentagem de suco, ratio, índice tecnológico, ácido ascórbico, índices de cor da polpa e da casca) foram coletados. As médias foram comparadas com a cultivar padrão Hamlin e analisadas pelo teste Dunnett. Para avaliar simultaneamente as características, foram aferidos os índices de desempenho para identificar cultivares promissoras que atendessem aos requisitos tanto para o processamento industrial como para o consumo in natura. Oliverlands foi a cultivar de laranja doce que registrou maior altura de planta e volume de copa, maior produção de frutos e maior eficiência produtiva em relação a cultivar Hamlin. Para o processamento industrial, a laranja Westin apresentou alto índice de desempenho enquanto que as laranjas Valência 2 e Salustiana registraram índices de desempenho favoráveis para consumo in natura. Não foram observados cultivares de laranja doce com dupla aptidão para o processamento industrial e consumo in natura na região sudoeste do Estado de São Paulo. / The number of sweet orange cultivars used in commercial orchards in Brazil is restricted, although the diversity of genera, species, cultivars and clones of citrus is great. However, the industrial processing is based on four main cultivars, the \'Hamlin\', as early maturing, the \'Pera\', as mid-season, and \'Natal\' and \'Valencia\' as late maturing cultivars. Anchored on these four cultivars, the orange juice industry processes fruits from June through December with greater intensity, January and February with lower supply, and the period from March through May is considered off season. Therefore, it is extremely important to select varieties that produce during this period. The objective of this study was to evaluate the horticultural performance of twelve early maturing sweet orange cultivars and identify those better than the \'Hamlin\' sweet orange, aiming to offer new options for producing fruits with quality, as for fresh fruit market as for industrial utilization, during early citrus harvest season in the southwest region of São Paulo state. The cultivars \'Hamlin\' (early maturing standard cultivar), \'Westin\', \'Pineapple\', \'Ruby\', \'Seleta Vermelha\', \'Mayorca\', \'Valencia 2\', \'Oliverlands\', \'Kawatta\', \'IAPAR 73\', \'Salustiana\' and \'Valencia Americana\' were evaluated. The experimental design was completely randomized with four replications, consisting of three plants of each cultivar per plot. Data concerning vegetative growth (plant height, stem diameter and canopy volume), production and yield efficiency, fruit morphology (mass, width, length, size, shell thickness and number of seeds) and the characteristics of internal fruit quality (total soluble solids, acidity, percentage of juice, \"ratio\", technological index, ascorbic acid, color indexes of pulp and peel) were collected The averages were compared to \'Hamlin\' sweet orange (standard cultivar) and analyzed by Dunnett test. To evaluate the characteristics simultaneously, performance indexes were estimated for identifying promising cultivars for utilization as for juice industry as for consumption fresh fruit market. \'Oliverlands\' was the sweet orange cultivar which showed higher plant height and plant volume, higher production and yield efficiency as compared to \'Hamlin\' sweet orange. The cultivar \'Westin\' showed higher performance index for the industrialization process, whereas \'Valencia 2\' and \'Salustiana\' sweet oranges had adequate performance indexes for fresh fruit market. There was no cultivar of sweet orange that had the simultaneous ability for the juice industry and for fresh fruit market in the southwestern region of Sao Paulo state.

Enquanto a toxidez de manganês (Mn) pode ser um problema comum nas regiões tropicais com predominância de solos ácidos, a deficiência deste nutriente, relatada em diversas espécies vegetais, tem sido atribuída principalmente ao uso excessivo de calcário. O estudo foi desenvolvido em casa-de-vegetação e teve como objetivo avaliar as causas de maior tolerância à toxidez de manganês e susceptibilidade à deficiência. Os cultivares de soja [Glycine max (L.) Merrill] Santa Rosa, IAC-15 e IAC-Foscarin 31 foram desenvolvidos em solução nutritiva (pH 4,97) com cinco níveis de Mn (0,5; 1,0; 2,0; 4,0 e 10,0 µmol/L), nos experimentos de eficiência de absorção e de uso (experimento 1), enquanto que para o estudo de tolerância ao excesso (experimento 2), as doses foram de 2,0; 100,0; 150,0; 200,0 e 250,0 µmol/L. Para as observações de anatomia e ultraestrutura (experimento 3), foram utilizadas três concentrações de Mn na solução nutritiva: 0,5; 2,0 (controle) e 200,0 µmol/L. O delineamento estatístico foi o de blocos completos ao acaso em esquema fatorial 5x3 (cinco doses de Mn e três cultivares), com três repetições. No experimento 1, os sintomas visuais de deficiência manifestaram-se, nos três cultivares, a partir do décimo dia após o início dos tratamentos, no estádio V3. Na condição do fornecimento das duas mais baixas doses, tanto as folhas inferiores quanto as superiores exibiram os sintomas de carência. As faixas de valores de concentração de Mn no tecido associadas à deficiência variaram entre 9 a 16 mg/kg nas folhas superiores e entre 15 a 26 mg/kg nas folhas inferiores. Ocorreu interação significativa entre as doses de Mn e os cultivares de soja para as produções de massa seca da parte aérea, de raízes e total. Para a produção de grãos e pericarpos constatou-se significância para as doses de Mn somente para IAC-15 e Santa Rosa. O cultivar IAC-Foscarin 31 não apresentou resposta às doses de Mn fornecidas, porém, mostrou-se eficiente na utilização de Mn para a produção de grãos. Os índices de eficiência de produção de grãos (IEP) calculados para IAC-Foscarin 31 (Mn-eficiente IEP>1,0), IAC-15 e Santa Rosa (Mn-pouco eficiente 0,5<IEP<1,0) foram, respectivamente, de 1,41; 0,78 e 0,66. Apesar do menor comprimento e superfície total de raízes produzidos pelo cultivar IAC-Foscarin 31, na condição de baixo suprimento de Mn, o acúmulo de Mn nas raízes, nos grãos e nas plantas foi superior ao dos demais cultivares. Os cultivares apresentaram comportamentos distintos na absorção de Mn, sendo o IAC-Foscarin 31 o mais eficiente na absorção (maior Vmax e menores valores de Km e Cmin) e o Santa Rosa o menos eficiente (menor valor de Vmax e maiores valores de Km e Cmin). No experimento 2, os cultivares IAC-15 e Santa Rosa exibiram sintomas visuais de toxidez de Mn. Os teores de Mn nas folhas associados ao excesso foram de 1.000,0 mg/kg. Entretanto, o IAC-15 apresentou maior produção de grãos e de massa seca da parte aérea, acompanhado pelo IAC-Foscarin 31 (intermediário) e o Santa Rosa (menor produção). O maior comprimento total de raízes, as maiores produções de massa seca de raízes e acúmulo de Mn neste tecido conferiram ao IAC-Foscarin 31 maior tolerância ao excesso de Mn na solução. A taxa de crescimento absoluto do sistema radicular, no início do desenvolvimento das plantas, pode conferir maior eficiência de absorção e maior tolerância ao excesso do elemento. As quantidades de Mn absorvidas no simplasto e apoplasto variaram entre os cultivares. A organização das células do mesófilo foliar (células parenquimáticas), do córtex radicular e das ultraestruturas celulares, como os cloroplastos, grãos de amido e glóbulos de lipídios é afetada pelas desordens nutricionais em Mn, principalmente, no cultivar IAC-15 e Santa Rosa. Há evidencias nas diferenças genotípicas entre os cultivares e que vários mecanismos atuam conjuntamente tanto na eficiência de absorção do Mn, em condição de baixa disponibilidade no substrato, quanto na capacidade de tolerar níveis excessivos do metal. / Manganese (Mn) toxicity may be a major constraint for crop production in acid soils of tropical countries. Nevertheless, deficiency has been recognized as a worldwide nutritional disorder frequently related to excessive lime. A greenhouse experiment was carried out with the objective of evaluating the efficiency of uptake of manganese and use in three-soybean cultivars [Glycine max (L.) Merrill] as well as their tolerance to manganese excess. Cultivars (Santa Rosa, IAC-15 and IAC-Foscarin 31) were evaluated under five rates of Mn (0.5; 1.0; 2.0; 4.0 and 10.0 µmol/L) in the nutrient solution (pH = 4.97) with respect to efficiency of uptake and of use. Other experiment was carried out with the objective of evaluating tolerance to manganese in the same cultivars when grown at five doses (2.0; 100.0; 150.0; 200.0 and 250.0 µmol/L). For anatomical and ultrastructures studies the Mn doses tested were 0.5; 2.0 (control) and 200.0 µmol/L. The experimental design was a 5x3 factorial of five Mn doses and three cultivars, set in a randomized block, with three replications. In experiment 1, visual symptoms of Mn deficiency (in both upper and lower leaves at the two lowest rates), started at the 10th day after transplanting of the three cultivars, at the V3 vegetative growth stage. The average of Mn concentration in the deficient upper leaves was close to 9 to 16 mg/kg, ranging from 15 to 26 mg/kg in the lower ones. Results showed significant interaction of Mn rates and cultivars with the dry matter of the tops, roots and total. Mn rates promoted increase in grain and pericarps yield only on IAC-15 and Santa Rosa cultivars. IAC-Foscarin 31 did not show grain yield responses to Mn supply. However, the indices (grain yield efficiency index) calculated for IAC-Foscarin 31, IAC-15 and Santa Rosa were, respectively, of 1.41; 0.78 and 0.66. They were therefore classified as Mn-Efficient (IEP>1.0) and of Mn-intermediate efficiency use (0.5<IEP<1.0). Although IAC-Foscarin 31 presented the lowest total root length and total root surface of the three cultivars even at low Mn doses, it had higher amount of Mn in roots, grains and whole plant than the other cultivars. The cultivars had distinct behavior in absorption of Mn. IAC-Foscarin 31 was more efficient. It showed higher Vmax and lower Km and Cmin than Santa Rosa and IAC-15. In experiment 2, IAC-15 and Santa Rosa leaves showed visual symptoms of Mn toxicity. The average Mn concentration in these leaf blades was close to 1,000.0 mg/kg. Nevertheless, IAC-15 had grain and dry matter in tops higher than IAC-Foscarin 31 (intermediate yield) and Santa Rosa. The highest total root length and root dry matter yield as well as root Mn content in IAC-Foscarin 31 contributes to explain differences in tolerance to Mn excess. The root absolute growth rate, at beginning of vegetative growth, may confer Mn uptake efficiency and tolerance as well. Total, symplastic and apoplastic Mn absorption varied among the three soybean genotypes. The effects of manganese deficiency and toxicity on the morphology of the roots (cortex, stele and vascular cylinder) and leaves (mesophyll tissues) and ultrastructure, like chloroplasts and its starch grains and lipid globules showed distinct degrees for the cultivars, being IAC-15 and Santa Rosa more affected. There are clear evidences of genotypics differences among the cultivars and that joint mechanisms are involved in the efficiency of absorption of low Mn, in the substrate, as well as in the tolerance to high levels.

Enquanto a toxidez de manganês (Mn) pode ser um problema comum nas regiões tropicais com predominância de solos ácidos, a deficiência deste nutriente, relatada em diversas espécies vegetais, tem sido atribuída principalmente ao uso excessivo de calcário. O estudo foi desenvolvido em casa-de-vegetação e teve como objetivo avaliar as causas de maior tolerância à toxidez de manganês e susceptibilidade à deficiência. Os cultivares de soja [Glycine max (L.) Merrill] Santa Rosa, IAC-15 e IAC-Foscarin 31 foram desenvolvidos em solução nutritiva (pH 4,97) com cinco níveis de Mn (0,5; 1,0; 2,0; 4,0 e 10,0 µmol/L), nos experimentos de eficiência de absorção e de uso (experimento 1), enquanto que para o estudo de tolerância ao excesso (experimento 2), as doses foram de 2,0; 100,0; 150,0; 200,0 e 250,0 µmol/L. Para as observações de anatomia e ultraestrutura (experimento 3), foram utilizadas três concentrações de Mn na solução nutritiva: 0,5; 2,0 (controle) e 200,0 µmol/L. O delineamento estatístico foi o de blocos completos ao acaso em esquema fatorial 5x3 (cinco doses de Mn e três cultivares), com três repetições. No experimento 1, os sintomas visuais de deficiência manifestaram-se, nos três cultivares, a partir do décimo dia após o início dos tratamentos, no estádio V3. Na condição do fornecimento das duas mais baixas doses, tanto as folhas inferiores quanto as superiores exibiram os sintomas de carência. As faixas de valores de concentração de Mn no tecido associadas à deficiência variaram entre 9 a 16 mg/kg nas folhas superiores e entre 15 a 26 mg/kg nas folhas inferiores. Ocorreu interação significativa entre as doses de Mn e os cultivares de soja para as produções de massa seca da parte aérea, de raízes e total. Para a produção de grãos e pericarpos constatou-se significância para as doses de Mn somente para IAC-15 e Santa Rosa. O cultivar IAC-Foscarin 31 não apresentou resposta às doses de Mn fornecidas, porém, mostrou-se eficiente na utilização de Mn para a produção de grãos. Os índices de eficiência de produção de grãos (IEP) calculados para IAC-Foscarin 31 (Mn-eficiente IEP>1,0), IAC-15 e Santa Rosa (Mn-pouco eficiente 0,5<IEP<1,0) foram, respectivamente, de 1,41; 0,78 e 0,66. Apesar do menor comprimento e superfície total de raízes produzidos pelo cultivar IAC-Foscarin 31, na condição de baixo suprimento de Mn, o acúmulo de Mn nas raízes, nos grãos e nas plantas foi superior ao dos demais cultivares. Os cultivares apresentaram comportamentos distintos na absorção de Mn, sendo o IAC-Foscarin 31 o mais eficiente na absorção (maior Vmax e menores valores de Km e Cmin) e o Santa Rosa o menos eficiente (menor valor de Vmax e maiores valores de Km e Cmin). No experimento 2, os cultivares IAC-15 e Santa Rosa exibiram sintomas visuais de toxidez de Mn. Os teores de Mn nas folhas associados ao excesso foram de 1.000,0 mg/kg. Entretanto, o IAC-15 apresentou maior produção de grãos e de massa seca da parte aérea, acompanhado pelo IAC-Foscarin 31 (intermediário) e o Santa Rosa (menor produção). O maior comprimento total de raízes, as maiores produções de massa seca de raízes e acúmulo de Mn neste tecido conferiram ao IAC-Foscarin 31 maior tolerância ao excesso de Mn na solução. A taxa de crescimento absoluto do sistema radicular, no início do desenvolvimento das plantas, pode conferir maior eficiência de absorção e maior tolerância ao excesso do elemento. As quantidades de Mn absorvidas no simplasto e apoplasto variaram entre os cultivares. A organização das células do mesófilo foliar (células parenquimáticas), do córtex radicular e das ultraestruturas celulares, como os cloroplastos, grãos de amido e glóbulos de lipídios é afetada pelas desordens nutricionais em Mn, principalmente, no cultivar IAC-15 e Santa Rosa. Há evidencias nas diferenças genotípicas entre os cultivares e que vários mecanismos atuam conjuntamente tanto na eficiência de absorção do Mn, em condição de baixa disponibilidade no substrato, quanto na capacidade de tolerar níveis excessivos do metal. / Manganese (Mn) toxicity may be a major constraint for crop production in acid soils of tropical countries. Nevertheless, deficiency has been recognized as a worldwide nutritional disorder frequently related to excessive lime. A greenhouse experiment was carried out with the objective of evaluating the efficiency of uptake of manganese and use in three-soybean cultivars [Glycine max (L.) Merrill] as well as their tolerance to manganese excess. Cultivars (Santa Rosa, IAC-15 and IAC-Foscarin 31) were evaluated under five rates of Mn (0.5; 1.0; 2.0; 4.0 and 10.0 µmol/L) in the nutrient solution (pH = 4.97) with respect to efficiency of uptake and of use. Other experiment was carried out with the objective of evaluating tolerance to manganese in the same cultivars when grown at five doses (2.0; 100.0; 150.0; 200.0 and 250.0 µmol/L). For anatomical and ultrastructures studies the Mn doses tested were 0.5; 2.0 (control) and 200.0 µmol/L. The experimental design was a 5x3 factorial of five Mn doses and three cultivars, set in a randomized block, with three replications. In experiment 1, visual symptoms of Mn deficiency (in both upper and lower leaves at the two lowest rates), started at the 10th day after transplanting of the three cultivars, at the V3 vegetative growth stage. The average of Mn concentration in the deficient upper leaves was close to 9 to 16 mg/kg, ranging from 15 to 26 mg/kg in the lower ones. Results showed significant interaction of Mn rates and cultivars with the dry matter of the tops, roots and total. Mn rates promoted increase in grain and pericarps yield only on IAC-15 and Santa Rosa cultivars. IAC-Foscarin 31 did not show grain yield responses to Mn supply. However, the indices (grain yield efficiency index) calculated for IAC-Foscarin 31, IAC-15 and Santa Rosa were, respectively, of 1.41; 0.78 and 0.66. They were therefore classified as Mn-Efficient (IEP>1.0) and of Mn-intermediate efficiency use (0.5<IEP<1.0). Although IAC-Foscarin 31 presented the lowest total root length and total root surface of the three cultivars even at low Mn doses, it had higher amount of Mn in roots, grains and whole plant than the other cultivars. The cultivars had distinct behavior in absorption of Mn. IAC-Foscarin 31 was more efficient. It showed higher Vmax and lower Km and Cmin than Santa Rosa and IAC-15. In experiment 2, IAC-15 and Santa Rosa leaves showed visual symptoms of Mn toxicity. The average Mn concentration in these leaf blades was close to 1,000.0 mg/kg. Nevertheless, IAC-15 had grain and dry matter in tops higher than IAC-Foscarin 31 (intermediate yield) and Santa Rosa. The highest total root length and root dry matter yield as well as root Mn content in IAC-Foscarin 31 contributes to explain differences in tolerance to Mn excess. The root absolute growth rate, at beginning of vegetative growth, may confer Mn uptake efficiency and tolerance as well. Total, symplastic and apoplastic Mn absorption varied among the three soybean genotypes. The effects of manganese deficiency and toxicity on the morphology of the roots (cortex, stele and vascular cylinder) and leaves (mesophyll tissues) and ultrastructure, like chloroplasts and its starch grains and lipid globules showed distinct degrees for the cultivars, being IAC-15 and Santa Rosa more affected. There are clear evidences of genotypics differences among the cultivars and that joint mechanisms are involved in the efficiency of absorption of low Mn, in the substrate, as well as in the tolerance to high levels.

A produção comercial brasileira de abacates ocorre em pomares implantados sobre porta-enxertos oriundos de sementes, o que resulta em grande desuniformidade das plantas com relação a tamanho da copa, produção, qualidade de frutos e suscetibilidade a patógenos do solo, principalmente Phytophthora cinnamomi, agente causal da podridão radicular, principal doença da cultura. Enquanto em outros países já é adotado o uso de porta-enxertos com características superiores que são propagados clonalmente visando minimizar esses problemas, no Brasil estes materiais ainda não foram avaliados. Durante os anos de 2010 a 2013 foi conduzido um experimento na Fazenda Jaguacy, município de Bauru, SP, com o objetivo de avaliar o desenvolvimento, produção e qualidade de frutos de abacateiro \'Hass\' sobre dois porta-enxertos, sendo um proveniente de sementes (\'Seedling\') (T1) e o outro da cultivar Dusa obtido por propagação clonal (T2). O experimento foi conduzido seguindo um delineamento em blocos casualizados, com dois tratamentos, 5 repetições e 10 plantas por parcela, totalizando 100 plantas em avaliação. O desenvolvimento vegetativo foi obtido pela medição da altura e diâmetro das plantas, utilizados para o cálculo do volume de copa. A produção foi avaliada a partir da contagem e pesagem de todos os frutos de cada planta e também pelo cálculo da eficiência produtiva e da alternância produtiva entre anos. A qualidade dos frutos foi avaliada a partir da massa, diâmetro e comprimento individual de uma amostra de 200 frutos por tratamento. Os dados foram submetidos à análise da variância, considerando nível de significância de 5%. Nenhuma diferença significativa foi observada entre os tratamentos para volume de copa, produção média, produção acumulada e número de frutos. Para as variáveis de eficiência produtiva, massa, comprimento, diâmetro e relação C:D de frutos ocorreram diferenças significativas que indicaram a superioridade do porta-enxerto clonal \'Dusa\' para plantas de \'Hass\' quando comparadas ao \'Seedling\'. / Avocado production in Brazil takes place in orchards established onto Seedling rootstocks, with large heterogeneity among plants regarding tree size, fruit yield and quality and susceptibility to soil pathogens, mainly Phytophthora cinnamomi that causes avocado root rot and is by far the main disease affecting this crop worldwide. While clonally obtained rootstocks are used in other countries to minimize such disadvantages, in Brazil such materials have not been yet evaluated. During 2010 to 2013 a trial was conducted in Fazenda Jaguacy farm, in Bauru county, with the aim to evaluate plant growth, fruit yield and quality of \'Hass\' avocados onto two rootstocks, a Seedling type (T1) and the \'Dusa\' clonal rootstock (T2). The trial was established after a completely randomized block design, with two treatments, 5 repetitions and 10 trees per plot, with a total of 100 measured trees. Tree size was evaluated by measurements of plant height and diameter, which were utilized to compute canopy volume. Fruit yield was obtained from counting and weighing all the fruits harvested at once from each tree, and also the yield efficiency and alternate bearing index were calculated. Fruit quality was determined from individual measurements of fruit weight, diameter (D) and length (L) on a 200-fruit sample randomly collected from each rootstock. Data was submitted to analysis of variance with a 5% significance level. No significant differences were observed among treatments for canopy volume, mean fruit yield, cumulative yield and fruit number. There were significant differences for yield efficiency, fruit weight, length, diameter and L:D ratio supporting the better performance of \'Dusa\' clonal rootstock on \'Hass\' scion as compared to the Seedling rootstock.

A produção comercial brasileira de abacates ocorre em pomares implantados sobre porta-enxertos oriundos de sementes, o que resulta em grande desuniformidade das plantas com relação a tamanho da copa, produção, qualidade de frutos e suscetibilidade a patógenos do solo, principalmente Phytophthora cinnamomi, agente causal da podridão radicular, principal doença da cultura. Enquanto em outros países já é adotado o uso de porta-enxertos com características superiores que são propagados clonalmente visando minimizar esses problemas, no Brasil estes materiais ainda não foram avaliados. Durante os anos de 2010 a 2013 foi conduzido um experimento na Fazenda Jaguacy, município de Bauru, SP, com o objetivo de avaliar o desenvolvimento, produção e qualidade de frutos de abacateiro \'Hass\' sobre dois porta-enxertos, sendo um proveniente de sementes (\'Seedling\') (T1) e o outro da cultivar Dusa obtido por propagação clonal (T2). O experimento foi conduzido seguindo um delineamento em blocos casualizados, com dois tratamentos, 5 repetições e 10 plantas por parcela, totalizando 100 plantas em avaliação. O desenvolvimento vegetativo foi obtido pela medição da altura e diâmetro das plantas, utilizados para o cálculo do volume de copa. A produção foi avaliada a partir da contagem e pesagem de todos os frutos de cada planta e também pelo cálculo da eficiência produtiva e da alternância produtiva entre anos. A qualidade dos frutos foi avaliada a partir da massa, diâmetro e comprimento individual de uma amostra de 200 frutos por tratamento. Os dados foram submetidos à análise da variância, considerando nível de significância de 5%. Nenhuma diferença significativa foi observada entre os tratamentos para volume de copa, produção média, produção acumulada e número de frutos. Para as variáveis de eficiência produtiva, massa, comprimento, diâmetro e relação C:D de frutos ocorreram diferenças significativas que indicaram a superioridade do porta-enxerto clonal \'Dusa\' para plantas de \'Hass\' quando comparadas ao \'Seedling\'. / Avocado production in Brazil takes place in orchards established onto Seedling rootstocks, with large heterogeneity among plants regarding tree size, fruit yield and quality and susceptibility to soil pathogens, mainly Phytophthora cinnamomi that causes avocado root rot and is by far the main disease affecting this crop worldwide. While clonally obtained rootstocks are used in other countries to minimize such disadvantages, in Brazil such materials have not been yet evaluated. During 2010 to 2013 a trial was conducted in Fazenda Jaguacy farm, in Bauru county, with the aim to evaluate plant growth, fruit yield and quality of \'Hass\' avocados onto two rootstocks, a Seedling type (T1) and the \'Dusa\' clonal rootstock (T2). The trial was established after a completely randomized block design, with two treatments, 5 repetitions and 10 trees per plot, with a total of 100 measured trees. Tree size was evaluated by measurements of plant height and diameter, which were utilized to compute canopy volume. Fruit yield was obtained from counting and weighing all the fruits harvested at once from each tree, and also the yield efficiency and alternate bearing index were calculated. Fruit quality was determined from individual measurements of fruit weight, diameter (D) and length (L) on a 200-fruit sample randomly collected from each rootstock. Data was submitted to analysis of variance with a 5% significance level. No significant differences were observed among treatments for canopy volume, mean fruit yield, cumulative yield and fruit number. There were significant differences for yield efficiency, fruit weight, length, diameter and L:D ratio supporting the better performance of \'Dusa\' clonal rootstock on \'Hass\' scion as compared to the Seedling rootstock.