Orientador: Giuliana Aparecida Santini Pigatto / Resumo: O setor citrícola brasileiro revela peculiaridades organizacionais e institucionais que, se bem compreendidas e estudadas, podem representar uma alternativa ao conhecido processo de redução do número de pequenos citricultores em atividade no cinturão da laranja. No século XXI, o fato das participações crescentes de pequenos citricultores em associações e cooperativas, a fim de fazer frente às incertezas de mercado, clama pela necessidade de estudos dessas formas de governança que representem um arranjo menos vertical e mais cooperativo entre agentes. Frente ao exposto, este trabalho tem como problema de investigação: A estrutura de governança em rede adotada por cooperativas citrícolas de pequenos produtores permite a redução dos riscos nas transações, ex-ante (seleção adversa) e ex-post (risco moral), e os problemas de oportunismo a jusante e a montante da cadeia produtiva? O objetivo geral da pesquisa consiste em analisar se a estrutura de governança em rede adotada por cooperativas citrícolas de pequenos produtores tem permitido a redução dos riscos nas transações, ex-ante (seleção adversa) e ex-post (risco moral), e os problemas de oportunismo a jusante e a montante da cadeia produtiva. O procedimento metodológico planejado compreendeu a estruturação e a realização de dois estudos de caso em cooperativas de pequenos produtores de laranja do interior do estado de São Paulo. As análises foram suportadas pelas abordagens da Economia dos Custos de Transação e de Rede Social. ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Brazilian citrus sector reveals organizational and institutional peculiarities that, if well understood and studied, can represent an alternative to the well-known process of reduction of small citrus producers operating in the orange belt. In the 21st century, the growing participation of small citrus producers in associations and cooperatives, in order to deal with market uncertainties, calls for the studies of these forms of governance that represent a less vertical and more cooperative arrangement between agents. Taking that into account, this work has the following research problem: The network governance structure adopted by small producers’ citrus cooperatives allows the reduction of risks in transactions, ex-ante (adverse selection) and ex-post (moral hazard), and the problems of opportunism downstream and upstream of the production chain? The general objective of the research is to analyze if the network governance structure adopted by small producers’ citrus cooperatives has allowed the reduction of risks in transactions, ex-ante (adverse selection) and ex-post (moral hazard), and the problems of opportunism downstream and upstream of the production chain. The planned methodological procedure included the structuring and research of two case studies in cooperatives of small orange producers in the interior of the state of São Paulo. The analyzes were supported by the Transaction Cost Economics and Social Network approaches. As a result, the importance of the coo... (Complete abstract click electronic access below) / Mestre

Thesis (M.Sc. Agriculture (Horticulture)) -- University of Limpopo, 2019 / Cucurbitacin-containing phytonematicides and a variety of unidentified soil microbes in suppressive soils (Biomuti) had been consistent in suppression of population densities of root-knot (Meloidogyne spp.) nematodes on various crops. However, information on suppressive effects of cucurbitacin-containing phytonematicides and Biomuti on citrus growth and suppression of the citrus nematode (Tylenchulus semipenetrans) had not been documented. The objective of this study therefore, was to determine the interactive effects of Nemarioc-AL and Nemafric-BL phytonematicides and Biomuti on growth and nutrient elements in leaf tissues of Poncirus trifoliata rootstock seedlings under greenhouse and field conditions. Uniform six-month-old citrus rootstock seedlings [Du Roi Nursery (Portion 21, Junction Farm, Letsitele)] were transplanted in 4 L plastic bags filled with growing mixture comprising steam-pasteurised (300°C for 1 h) loam and compost (cattle manure, chicken manure, sawdust, grass, woodchips and effective microorganisms) at 4:1 (v/v) ratio and placed on greenhouse benches. A 2 × 2 × 2 factorial experiment with the first, second and third factors being Nemarioc-AL phytonematicide (A) and Nemafric-BL phytonematicide (B) and Biomuti (M), were arranged in randomized complete block design, with 10 blocks. The treatment combinations were A0B0M0, A1B0M0, A0B1M0, A0B0M1, A1B1M0, A1B0M1, A0B1M1 and A1B1M1, with 1 and 0 signifying with and without the indicated factor. Treatments were applied at 3% dilution for each product as substitute to irrigation at a 17-day application interval. Under greenhouse conditions, seedlings were irrigated every other day with 300 ml chlorine-free tap water. Under field conditions, the study was executed using similar procedures to those in the greenhouse trial, except that the citrus seedlings were transplanted directly into the soil of a prepared field and seedlings were irrigated using drip irrigation for 2 h every xxi other day. At 64 days after transplanting, plant growth variables were measured and foliar nutrient elements were quantified using the Inductively Coupled Plasma Optical Emission Spectrometry (ICPE-9000). Data were subjected to analysis of variance using SAS software. Significant second and first order interactions were further expressed using the three-way and two-way tables, respectively. At 64 days after the treatments, under greenhouse conditions Nemarioc-AL × Nemafric-BL × Biomuti interaction was not significant (P ≤ 0.05) on plant variables of seedling rootstocks in both experiments. In contrast, the Nemarioc-AL × Biomuti interaction was highly significant (P ≤ 0.01) on stem diameter, contributing 52% in TTV of the variable in Experiment 1 (Table 3.1), whereas in Experiment 2 the interaction was highly significant on dry shoot mass, contributing 33% in TTV of the variable (Table 3.2). Relative to untreated control, the two-way matrix showed that the Nemarioc-AL × Biomuti interaction, Nemarioc-AL phytonematicide and Biomuti each increased stem diameter by 1%, 12% and 5%, respectively (Table 3.3). Relative to untreated control, the two-way matrix table showed that Nemarioc-AL × Biomuti interaction increased dry shoot mass by 10%, whereas Nemarioc-AL phytonematicide and Biomuti each increased dry shoot mass by 23% and 17%, respectively (Table 3.4). Nemarioc-AL × Nemafric-BL × Biomuti interaction was not significant (P ≤ 0.05) for all plant growth variables in both experiments. However, Nemarioc-AL × Nemafric-BL interaction was significant for leaf number and stem diameter contributing 45% and 29% in TTV of the respective variables in Experiment 2 (Table 4.1). Relative to untreated control, two way matrix table showed that the Nemarioc-AL × Nemafric-BL interaction and Nemafric-BL phytonematicides each increased stem diameter by 8% and 11% respectively, whereas Nemarioc-AL phytonematicides reduced stem diameter by 2% (Table 4.2). Also using two-way matrix table showed that Nemarioc-AL and Nemafric xxii BL phytonematicides each increased leaf number by 1% and 7% respectively, whereas the Nemarioc-AL × Nemafric-BL interaction increased leaf number by 6% (Table 4.2). Nemafric-BL × Biomuti interaction was significant for stem diameter contributing 29% in TTV of the respective variable in Experiment 2 (Table 4.1). Using two-way matrix table showed that Nemafric-BL × Biomuti interaction and Nemafric-BL phytonematicide each increased stem diameter by 7%, whereas Biomuti alone reduced stem diameter by 6% (Table 4.3). Under greenhouse conditions, the second order Nemarioc-AL × Nemafric-BL × Biomuti interaction was highly significant for foliar Mg, contributing 5% in TTV of the variable in Experiment 1 (Table 3.4). Relative to untreated control, the three-way matrix table showed that the three factors, Nemafric BL phytonematicide and Biomuti each reduced Mg by 33%, 35% and 53%, respectively, whereas Nemarioc-AL phytonematicide increased Mg by 12% (Table 3.5). Nemarioc-AL × Biomuti interaction was highly significant for foliar Mg, contributing 9% in TTV of the variable in Experiment 1 (Table 3.4). Relative to untreated control, the two-way matrix table showed that the Nemarioc-AL × Biomuti interaction and Nemafric-BL phytonematicide reduced Mg by 42% and 12%, respectively, whereas Nemarioc-AL phytonematicide alone increased Mg by 14% (Table 3.6). Nemarioc-AL × Biomuti interaction was highly significant for foliar Ca and Mg, contributing 59 and 4% in TTV of the respective variables in Experiment 1 (Table 3.4). Also using two-way matrix table showed that Nemarioc-AL phytonematicide and Biomuti separately reduced Ca by 12% and 22% respectively, whereas the Nemarioc-AL × Biomuti interaction increased Ca by 1% (Table 3.7). Relative to untreated control, the Nemarioc-AL × Biomuti interaction, Nemarioc-AL phytonematicide and Biomuti reduced foliar Mg by 26%, 21% and 33%, respectively (Table 3.7). Nemafric-BL × Biomuti interaction was highly significant for foliar Mg and P, contributing 50 and 21% xxiii in Experiment 1, whereas in Experiment 2 the interaction was significant for foliar Ca and Mg, contributing 41% and 38% in TTV of the respective variables (Table 3.4). Relative to untreated control, the two-way matrix table showed that Nemafric-BL phytonematicide and Biomuti individually reduced Mg by 60% and 51%, respectively, whereas the Nemafric-BL × Biomuti interaction reduced Mg by 38% (Table 3.8). Also, in the two-way matrix table the Nemafric-BL × Biomuti interaction and Nemafric-BL phytonematicide each reduced Mg by 13% and 2%, respectively, whereas Biomuti alone increased P by 17% (Table 3.8). Relative to untreated control, Nemafric-BL phytonematicide and Biomuti reduced Ca by 29% and 18%, respectively, whereas Nemafric-BL × Biomuti interaction reduced Ca by 14% (Table 3.9). Using two-way matrix table showed that Nemafric-BL phytonematicide and Biomuti separately reduced Mg by 21%, whereas the Nemafric-BL × Biomuti interaction reduced Mg by 16% (Table 3.9). Interaction of Nemarioc-AL × Nemafric-BL × Biomuti had no significant effect on K, Na and Zn in both experiments. Under field conditions, the second order Nemarioc-AL × Nemafric-BL × Biomuti interaction was not significant for all the nutrient elements in Experiment 1. Nemarioc-AL × Biomuti was significant for Ca, K and highly significant for Mg and P, contributing 31, 8, 23 and 19% in TTV of the respective variables in Experiment 1 (Table 4.4). Relative to untreated control, two-way matrix table showed that Nemarioc-AL phytonematicide and Biomuti each increased Ca by 15% and 26% repectiviely, whereas the Nemarioc-AL × Biomuti increased Ca by 17% (Table 4.5). Interaction of Nemarioc-AL × Biomuti, Nemarioc-AL phytonematicide and Biomuti each reduced Mg by 48%, 70% and 37% (Table 4.5). Also using two-way matrix table showed that Nemarioc-AL phytonematicide and Biomuti each increased P by 4% and 5% respectively, whereas the Nemarioc-AL × Biomuti interaction increased P by 50% (Table 4.5). Realative to untreated control, xxiv Biomuti and Nemarioc-AL phytonematicide each reduced K by 10% and 5% respectively, whereas the Nemarioc-AL × Nemafric-BL interaction reduced K by 38% (Table 4.7). Nemafric-BL × Biomuti interaction was highly significant for Mg and Zn, contributing 11% and 29% in TTV of the respective variables in Experiment 1 (Table 4.4). Relative to untreated control, two-way matrix table showed that Nemarioc-AL phytonematicide and Biomuti separately increased Mg by 1% and 19% respectiviely, whereas the Nemafric-BL × Biomuti interaction reduced Mg by 43% (Table 4.6). Nemafric-BL × Biomuti interaction, Nemafric-BL phytonematicide and Biomuti each reduced Zn by 35%, 31% and 64% (Table 4.6). Using three-way matrix table showed that the Nemarioc-AL × Nemafric-BL × Biomuti, Nemarioc-AL × Nemafric-BL, Nemarioc-AL × Biomuti and Nemafric-BL × Biomuti interactions each increased Ca by 44%, 18%,10% and 24% (Table 4.8). Further the matrix showed that Nemarioc-AL, Nemafric-BL phytonematicides and Biomuti each increased Ca by 25%, 31% and 23% (Table 4.8). Under both greenhouse and field conditions, although second and first order interactions were not consistent of various variables, results demonstrated that the three products interacted significantly for various products. In conclusion, the study suggested that these innovative products could be used in combination with Biomuti to stimulate plant growth but had antagonistic effects on accumulation of nutrient elements in P. trifoliata rootstock seedlings, suggesting that the products should be applied separately. / Agricultural Research Council-Universities Collaboration Centre and the National Research Foundation (NRF)

Com as novas tecnologias de produção visando maiores lucratividades e sustentabilidade, as técnicas e ferramentas da agricultura de precisão (AP) vêm sendo avaliadas pelos produtores na gestão de pomares comerciais de citros. A AP leva em consideração a desuniformidade das lavouras, tentando buscar soluções e ferramentas para melhor explorar tais variabilidades. As técnicas propostas se baseiam na variabilidade espacial existente no campo e em ações de manejo implementadas de forma localizada, em taxa variável, ou seja, de acordo com a demanda local pelos insumos. Já existem metodologias para confecção de mapas de produtividade em citros, um dos passos essenciais para o início da implantação da AP nas propriedades, e assim, o possível processamento dos dados e aplicação de fertilizantes e corretivos em taxas variadas. O objetivo deste trabalho foi avaliar os efeitos de aplicações em taxa fixa e variável sobre a produtividade e os parâmetros de fertilidade do solo bem como sobre o consumo de fertilizantes e calcário em talhões de citros em larga escala (ao longo de sete safras). O estudo foi conduzido durante sete anos, de 2011 a 2017 e englobou áreas experimentais em pomares que se localizam na fazenda Rio Pardo, município de Iaras - SP (22º57\'03,5\"S; 48º39\'37,4\"W) e consistiam em dez talhões de aproximadamente 25 hectares implantados em 2008 e 2009. Cinco talhões foram conduzidos utilizando o tratamento \"Dose fixa\" (DF) e cinco \"Dose variável\" (DV). O processamento dos dados consistia na realização da análise exploratória inicial, filtragens e limpezas, análises geoestatísticas, interpolações e recomendações dos insumos. No tratamento DF, os insumos foram aplicados seguindo a metodologia convencional de adubação, uma amostra de solo e folha era retirada de cada talhão e com base na expectativa de produção, a necessidade de insumos era calculada. No tratamento DV, as amostragens eram georreferenciadas e realizadas a cada um hectare. As recomendações de fósforo, potássio, calcário e nitrogênio foram calculadas com base nos mapas de produtividade do ano anterior e com os resultados laboratoriais das amostragens. As aplicações de P, K e N do tratamento DV não foram reduzidas quando comparadas às aplicações do tratamento DF, porém as aplicações em doses variadas apresentaram maiores eficiências na aplicação. Os valores médios de P e K nos solos se diferiram estatisticamente somente nos anos de 2013/14 e 2014/15, sendo maiores no tratamento DV. A produtividade no tratamento DV foi maior quando comparada ao tratamento DF e nas comparações entre os anos, em quatro safras o tratamento DV apresentou maiores produtividades, chegando a aumentos de 26% de produção de frutas e cerca de 2,74 t ha-1 na média nos seis anos avaliados. / With all the new and advance in production technologies, that aims for a greater profitability and sustainability, techniques and tools used in precision agriculture (PA) are starting to be evaluated by the producers in the management of citrus commercial fields. PA considers the unequal nature of the crops, willing to find solutions and procedures to exploit such variabilities with better results. The proposed techniques are based on spatial variability in the field and on management actions implemented locally, at varied rates, in other words, according to local demand for inputs. It is known that already exists some methodologies for making and developing maps of citrus productivity, one of the essential procedures of the implantation of PA in properties, and thus, the possible processing of data and application of fertilizers and correctives in varied rates. The objective of this paper was to evaluate the effects of fixed and variable rate applications on productivity and soil fertility parameters as well as on fertilizer and limestone consumption in large-scale citrus stands (over seven harvests). The study was developed for seven years, from 2011 to 2017 in experimental areas within orchards located in the Rio Pardo farm, in the municipality of Iaras - SP (22º57\'03.5 \"S; 48º39\'37.4\" W) and consisted of ten plots of approximately 25 hectares established in 2008 and 2009. Five plots were conducted using the \"Fixed-rates\" (DF) and five \"variable rates\" (DV) treatments. The data processing procedure consisted of performing the initial exploratory analysis, filtering and cleaning data, geostatistical analysis, interpolations and recommendations of the inputs. In the DF treatment, the inputs were applied according to the conventional fertilization methodology, a soil and leaf sample was with drawn from each plot and, based on the expected production, the input requirement was calculated. In the DV treatment, the samplings were georeferenced and carried out to each hectare. The recommendations for phosphorus, potassium, limestone, and nitrogen were calculated based on the previous year\'s productivity maps and the laboratory results of the samplings. The applications of P, K, and N of the DV treatment were not reduced when compared to the applications of DF treatment, but the applications in varied rates presented better efficiencies in the application. The medium values of P and K in soils differed statistically only in the years 2013/14 and 2014/15 and were higher in DV treatment. The productivity in the DV treatment was higher when compared to the treatment DF and in the comparisons between the years, in four harvests the DV treatment presented higher productivities, presenting increases of 26% of fruit production and around 2.74 t ha-1 on average in the six years evaluated.

A morte súbita dos citros (MSC) foi identificada em 2001, no município de Comendador Gomes, Minas Gerais, e desde então foi responsável pela perda de 4 milhões de plantas na região sul do Triângulo Mineiro, e no norte e noroeste do estado de São Paulo. É uma doença de combinação copa/porta-enxerto, afetando principalmente laranjeira doce enxertada em limoeiro Cravo, e que culmina na morte das plantas. Passados dez anos do seu relato, até hoje não se tem conhecimento exato do agente causal e dos possíveis vetores. Sabe-se, todavia, que em todas as plantas com morte súbita encontram-se o vírus da tristeza dos citros (Citrus tristeza virus - CTV) e um vírus do Gênero Marafivirus, Família Tymoviridae, denominado Citrus sudden death associated virus (CSDaV). Devido esse fato, há a necessidade de separá-los para testar os postulados de Koch para o CSDaV. O principal objetivo deste trabalho foi tentar isolar o CSDaV para verificar o seu real envolvimento com a MSC. Também se procurou purificar esse vírus para a produção de antissoro policlonal para trabalhos de diagnose da doença. Para a purificação do CSDaV foi utilizado o protocolo de purificação do Potato leaf roll virus, porém os resultados não foram satisfatórios devido a constante presença do CTV. Tentativas de remoção do CTV por meio de imunoprecipitação com antissoro homólogo não foram satisfatórias. O antissoro produzido reagiu indistintamente com extratos de plantas infectadas com o CSDaV e o CTV. O CSDaV foi transmitido mecanicamente para plantas de Nicotiana sp., N. clevelandii, Chenopodium amaranticolor e C. quinoa, causando principalmente infecção localizada. A presença do vírus foi confirmada por RT-PCR e a sua identidade por meio do sequenciamento de nucleotídeos do produto da amplificação. Tentativas de transmissão do CSDaV usando inóculo de extrato de folhas de plantas do campo , por meio da Cuscuta sp., através de cortes no tronco das plantas com lâmina embebida no inóculo, com pulgões Toxoptera citricida aparentemente virulíferos somente para o tymovirus e por meio da inoculação de sementes de citros deram resultados negativos. / Citrus sudden death (CSD) disease was identified in 2001, at Comendador Comes County, State of Minas Gerais, Brazil. Since then the disease has caused the death of 4 million trees in Southwestern Minas Gerais State and Northern São Paulo State. This new and destructive disease affects sweet orange as well as other species, varieties, and hybrids when grafted on Rangpur (Citrus limonia). Then years after the first report on CSD, the causal agent and possible vector(s) have not been precisely identified. It is known, however, that all disease trees are infected with Citrus tristeza virus (CTV) and Citrus sudden death associate virus (CSDaV), which is a member of the Genus Marafivirus, Famíly Tymoviridae. Due to this, it is necessary to separate these pathogens, in order to complete Kochs postulated for the CSDaV. The main purpose of the present work was to try to isolate the CSDaV to verify its role on CSD disease. In addition, attempts were done to purify the virus and produce polyclonal antiserum for disease diagnosis. Purification was carried out as described for Potato leaf roll virus, but results were not suitable due to the constant presence of CTV. Efforts to remove CTV by immunoprecipitation with homologous antiserum did not succeed. The produced antiserum reacted indistinctly with extracts of plants infected with both viruses. SCDaV was mechanically transmitted to Nicotiana sp., N. clevelandii, Chenopodium amaranticolor, and C. quinoa, causing mainly local infection. Infection was confirmed by RT-PCR and virus identity was determined by nucleotide sequence of the amplified fragment. Efforts to transmit CSDaV, using as inoculum extract from field infected plants, by means of Cucucuta sp., by incisions on the trunk of the test-plants, with Toxoptera citricida apparently viruliferous only for the tymovirus, and by means of citrus seed inoculation gave negative results.

A presente dissertação constitui-se num estudo de caso que versa acerca da utilização da tecnologia GIS (Geographic Information System) no processo de inspeção agrícola. A pesquisa teve o caráter exploratório com metodologia qualitativa, tendo como técnicas de pesquisa a revisão bibliográfica, a fim de identificar os conceitos atinentes ao tema, análise documental, entrevistas semi-estruturadas e observação de campo. O significativo e constante crescimento da citricultura paulista no cenário mundial do agronegócio reforça a necessidade de se criar mecanismos para controle e desenvolvimento da atividade. Dessa forma, o referido estudo apresenta a compreensão e análise da utilização de uma tecnologia baseada em sistema de informação geográfica (software livre), desenvolvido por um centro nacional de pesquisa agropecuária, aplicada ao processo de inspeção citrícola de um instituto de pesquisa em citros, localizado na cidade de Araraquara, no Estado de São Paulo. / This work is based on a study of case about the use of the GIS (Geographic Information System) at the process of agricultural inspection. The research was an exploration using the qualitative methodology based on the bibliography review in order to identify the concepts of the theme, documental analyses, semi structured interviews and environmental research. A constant fairly increasing of the paulista citriculture worldwide reinforces the necessity of the creation of a mechanism to control and develop the activity. This way, the mentioned study presents comprehension and analyses of the technology utilization based on a geographic information system (free software), developed by a national center of agropecure research, applied to the process of citric inspection in an institute of research in citric placed in Araraquara in São Paulo state, Brazil.

A deficiência de boro (B) é comum nos pomares citrícolas paulistas. A maioria das pesquisas sobre mobilidade (transporte e redistribuição) de micronutrientes têm sido realizadas com o auxílio de isótopos radioativos, entretanto, para o B não existe um isótopo radioativo com meia vida suficientemente longa para tais estudos. Os isótopos estáveis de B (10B e 11B) foram pouco utilizados como traçador em estudos com vegetais, devido à dificuldade de detecção, entretanto, com o advento do ICP-MS (inductively coupled plasma mass spectrometry – espectrômetro de massas acoplado a uma fonte de plasma),tornou-se possível quantificar os átomos de 10B e 11B. Desta forma, utilizando-se de compostos enriquecidos em 10B, tornaram-se viáveis os estudos de absorção, transporte e redistribuição do B nas plantas. O objetivo do presente trabalho foi estudar, com o auxilio da técnica isotópica, a absorção de B pelas raízes e folhas da laranjeira, verificar a mobilidade do elemento na planta e quantificar a contribuição da adubação com B para os frutos da laranjeira. No estudo foram realizados 4 experimentos, sendo 3 experimentos realizados em casa de vegetação e 1 experimento realizado em pomar de laranjeira em produção. Dos experimentos realizados em casa de vegetação, O primeiro estudou a absorção de B pelas raízes de laranjeiras em sistema hidropônico e a mobilidade do nutriente na planta. Laranjeiras de copa ‘Valencia’ em dois porta-enxertos (limoeiro ‘Cravo’ e citrumelo ‘Swingle’) foram conduzidas em soluções nutritivas com concentrações de B adequadas ou deficientes, e o início dos tratamentos com 10B ocorreram em épocas distintas, com plantas em diferentes condições nutricionais de B. O segundo experimento estudou a eficiência da absorção foliar de B pelas laranjeiras ao longo do tempo e a mobilidade do nutriente na planta. O terceiro experimento comparou a mobilidade do B, absorvido pelas raízes e pelas folhas, para os novos fluxos de crescimento. O quarto experimento, realizado no campo, comparou as adubações com B no solo, via fertirrigação, e nas folhas das laranjeiras. Avaliou a contribuição destas adubações para os frutos das laranjeiras e verificou o efeito residual da adubação realizada no ano anterior na nutrição da planta no ano seguinte. Pelos resultados obtidos nos experimentos foi possível verificar que cerca de 20% a 40% do B presente nas partes novas da laranjeira foi proveniente de reservas das laranjeiras, ou seja, foi redistribuído na planta, e o menor valor foi obtido quando as laranjeiras estavam deficientes em B. A absorção de B pelas folhas da laranjeira foi inferior a 9% total de B depositado nas folhas, e o nutriente permaneceu principalmente nos órgãos onde foi aplicado (97%). A adubação com B no solo foi, cerca de 3 a 4 vezes, mais eficiente em fornecer o nutriente para a laranjeira, do que a aplicação do nutriente na folha. / Boron deficiency is widespread in São Paulo citrus orchards. Most of researches on micronutrients mobility (transport and redistribution) have been carried out using radioactive isotopes, however, for the B there is not any radioactive isotope with half-life enough for such studies. The B stable isotopes (10B and 11B) had little been used as tracer in plant studies due to the difficult detection, but with the development of the ICP-MS inductively coupled plasma mass spectrometry), it is possible to quantify the atoms of 10B and 11B. This way, using enriched compound with 10B, the absorption, transport and redistribution studies have become possible.The present work aimed to study, with aid of isotopic methodology, the B absorption through the roots and leaf of orange plant, to verify the B mobility in the plant and to quantify the B fertilization contribution to the fruit. In the study 4 experiments were carried out, 3 experiments in greenhouse and 1 experiment in a productive orange orchard. From the experiment carried out in greenhouse, in the first one the B absorption through the roots in nutrient solution system and the nutrient mobility in the plant were studied. ‘Valencia’ sweet orange trees budded on Rangpur lime or Swingle citrumelo were grown in nutrient solution with suitable or deficient B supply, and the treatments with 10B were initiated in different periods with plants in different nutritional condition of B. The second experiment studied the efficiency of B uptake by the orange leaves, which were harvested in different periods after 10B spraying, and the nutrient mobility in the plant. The third experiment compared the B mobility absorbed through roots and leaves, and driven to the new shoots. The fourth experiment, performed in orange orchard, compared the B applied in the soil by fertigation and in the leaves. The contribution of B from fertilizer to the fruits was evaluated and verified the residual effect of fertilizer applied in the year before on the plant nourishing in the next year. By the results from the experiments it was possible to verify that approximately 20% to 40% of B contained in the new parts of orange plant was derivated from old parts, in other words, the B was redistributed in the plant, and the lower value was obtained when the plants grew in nutrient solution with deficient B supply. The B absorption by the leaves was less than 9% of total B deposited on the foliar lamina, and remained mainly in the sites where it was applied (97%). The B fertilization in the soil was, approximately 3 to 4 times more efficient in providing B to the orange plant than the B sprayed on the leaves.

A deficiência de boro (B) é comum nos pomares citrícolas paulistas. A maioria das pesquisas sobre mobilidade (transporte e redistribuição) de micronutrientes têm sido realizadas com o auxílio de isótopos radioativos, entretanto, para o B não existe um isótopo radioativo com meia vida suficientemente longa para tais estudos. Os isótopos estáveis de B (10B e 11B) foram pouco utilizados como traçador em estudos com vegetais, devido à dificuldade de detecção, entretanto, com o advento do ICP-MS (inductively coupled plasma mass spectrometry – espectrômetro de massas acoplado a uma fonte de plasma),tornou-se possível quantificar os átomos de 10B e 11B. Desta forma, utilizando-se de compostos enriquecidos em 10B, tornaram-se viáveis os estudos de absorção, transporte e redistribuição do B nas plantas. O objetivo do presente trabalho foi estudar, com o auxilio da técnica isotópica, a absorção de B pelas raízes e folhas da laranjeira, verificar a mobilidade do elemento na planta e quantificar a contribuição da adubação com B para os frutos da laranjeira. No estudo foram realizados 4 experimentos, sendo 3 experimentos realizados em casa de vegetação e 1 experimento realizado em pomar de laranjeira em produção. Dos experimentos realizados em casa de vegetação, O primeiro estudou a absorção de B pelas raízes de laranjeiras em sistema hidropônico e a mobilidade do nutriente na planta. Laranjeiras de copa ‘Valencia’ em dois porta-enxertos (limoeiro ‘Cravo’ e citrumelo ‘Swingle’) foram conduzidas em soluções nutritivas com concentrações de B adequadas ou deficientes, e o início dos tratamentos com 10B ocorreram em épocas distintas, com plantas em diferentes condições nutricionais de B. O segundo experimento estudou a eficiência da absorção foliar de B pelas laranjeiras ao longo do tempo e a mobilidade do nutriente na planta. O terceiro experimento comparou a mobilidade do B, absorvido pelas raízes e pelas folhas, para os novos fluxos de crescimento. O quarto experimento, realizado no campo, comparou as adubações com B no solo, via fertirrigação, e nas folhas das laranjeiras. Avaliou a contribuição destas adubações para os frutos das laranjeiras e verificou o efeito residual da adubação realizada no ano anterior na nutrição da planta no ano seguinte. Pelos resultados obtidos nos experimentos foi possível verificar que cerca de 20% a 40% do B presente nas partes novas da laranjeira foi proveniente de reservas das laranjeiras, ou seja, foi redistribuído na planta, e o menor valor foi obtido quando as laranjeiras estavam deficientes em B. A absorção de B pelas folhas da laranjeira foi inferior a 9% total de B depositado nas folhas, e o nutriente permaneceu principalmente nos órgãos onde foi aplicado (97%). A adubação com B no solo foi, cerca de 3 a 4 vezes, mais eficiente em fornecer o nutriente para a laranjeira, do que a aplicação do nutriente na folha. / Boron deficiency is widespread in São Paulo citrus orchards. Most of researches on micronutrients mobility (transport and redistribution) have been carried out using radioactive isotopes, however, for the B there is not any radioactive isotope with half-life enough for such studies. The B stable isotopes (10B and 11B) had little been used as tracer in plant studies due to the difficult detection, but with the development of the ICP-MS inductively coupled plasma mass spectrometry), it is possible to quantify the atoms of 10B and 11B. This way, using enriched compound with 10B, the absorption, transport and redistribution studies have become possible.The present work aimed to study, with aid of isotopic methodology, the B absorption through the roots and leaf of orange plant, to verify the B mobility in the plant and to quantify the B fertilization contribution to the fruit. In the study 4 experiments were carried out, 3 experiments in greenhouse and 1 experiment in a productive orange orchard. From the experiment carried out in greenhouse, in the first one the B absorption through the roots in nutrient solution system and the nutrient mobility in the plant were studied. ‘Valencia’ sweet orange trees budded on Rangpur lime or Swingle citrumelo were grown in nutrient solution with suitable or deficient B supply, and the treatments with 10B were initiated in different periods with plants in different nutritional condition of B. The second experiment studied the efficiency of B uptake by the orange leaves, which were harvested in different periods after 10B spraying, and the nutrient mobility in the plant. The third experiment compared the B mobility absorbed through roots and leaves, and driven to the new shoots. The fourth experiment, performed in orange orchard, compared the B applied in the soil by fertigation and in the leaves. The contribution of B from fertilizer to the fruits was evaluated and verified the residual effect of fertilizer applied in the year before on the plant nourishing in the next year. By the results from the experiments it was possible to verify that approximately 20% to 40% of B contained in the new parts of orange plant was derivated from old parts, in other words, the B was redistributed in the plant, and the lower value was obtained when the plants grew in nutrient solution with deficient B supply. The B absorption by the leaves was less than 9% of total B deposited on the foliar lamina, and remained mainly in the sites where it was applied (97%). The B fertilization in the soil was, approximately 3 to 4 times more efficient in providing B to the orange plant than the B sprayed on the leaves.

A presente dissertação constitui-se num estudo de caso que versa acerca da utilização da tecnologia GIS (Geographic Information System) no processo de inspeção agrícola. A pesquisa teve o caráter exploratório com metodologia qualitativa, tendo como técnicas de pesquisa a revisão bibliográfica, a fim de identificar os conceitos atinentes ao tema, análise documental, entrevistas semi-estruturadas e observação de campo. O significativo e constante crescimento da citricultura paulista no cenário mundial do agronegócio reforça a necessidade de se criar mecanismos para controle e desenvolvimento da atividade. Dessa forma, o referido estudo apresenta a compreensão e análise da utilização de uma tecnologia baseada em sistema de informação geográfica (software livre), desenvolvido por um centro nacional de pesquisa agropecuária, aplicada ao processo de inspeção citrícola de um instituto de pesquisa em citros, localizado na cidade de Araraquara, no Estado de São Paulo. / This work is based on a study of case about the use of the GIS (Geographic Information System) at the process of agricultural inspection. The research was an exploration using the qualitative methodology based on the bibliography review in order to identify the concepts of the theme, documental analyses, semi structured interviews and environmental research. A constant fairly increasing of the paulista citriculture worldwide reinforces the necessity of the creation of a mechanism to control and develop the activity. This way, the mentioned study presents comprehension and analyses of the technology utilization based on a geographic information system (free software), developed by a national center of agropecure research, applied to the process of citric inspection in an institute of research in citric placed in Araraquara in São Paulo state, Brazil.

A morte súbita dos citros (MSC) foi identificada em 2001, no município de Comendador Gomes, Minas Gerais, e desde então foi responsável pela perda de 4 milhões de plantas na região sul do Triângulo Mineiro, e no norte e noroeste do estado de São Paulo. É uma doença de combinação copa/porta-enxerto, afetando principalmente laranjeira doce enxertada em limoeiro Cravo, e que culmina na morte das plantas. Passados dez anos do seu relato, até hoje não se tem conhecimento exato do agente causal e dos possíveis vetores. Sabe-se, todavia, que em todas as plantas com morte súbita encontram-se o vírus da tristeza dos citros (Citrus tristeza virus - CTV) e um vírus do Gênero Marafivirus, Família Tymoviridae, denominado Citrus sudden death associated virus (CSDaV). Devido esse fato, há a necessidade de separá-los para testar os postulados de Koch para o CSDaV. O principal objetivo deste trabalho foi tentar isolar o CSDaV para verificar o seu real envolvimento com a MSC. Também se procurou purificar esse vírus para a produção de antissoro policlonal para trabalhos de diagnose da doença. Para a purificação do CSDaV foi utilizado o protocolo de purificação do Potato leaf roll virus, porém os resultados não foram satisfatórios devido a constante presença do CTV. Tentativas de remoção do CTV por meio de imunoprecipitação com antissoro homólogo não foram satisfatórias. O antissoro produzido reagiu indistintamente com extratos de plantas infectadas com o CSDaV e o CTV. O CSDaV foi transmitido mecanicamente para plantas de Nicotiana sp., N. clevelandii, Chenopodium amaranticolor e C. quinoa, causando principalmente infecção localizada. A presença do vírus foi confirmada por RT-PCR e a sua identidade por meio do sequenciamento de nucleotídeos do produto da amplificação. Tentativas de transmissão do CSDaV usando inóculo de extrato de folhas de plantas do campo , por meio da Cuscuta sp., através de cortes no tronco das plantas com lâmina embebida no inóculo, com pulgões Toxoptera citricida aparentemente virulíferos somente para o tymovirus e por meio da inoculação de sementes de citros deram resultados negativos. / Citrus sudden death (CSD) disease was identified in 2001, at Comendador Comes County, State of Minas Gerais, Brazil. Since then the disease has caused the death of 4 million trees in Southwestern Minas Gerais State and Northern São Paulo State. This new and destructive disease affects sweet orange as well as other species, varieties, and hybrids when grafted on Rangpur (Citrus limonia). Then years after the first report on CSD, the causal agent and possible vector(s) have not been precisely identified. It is known, however, that all disease trees are infected with Citrus tristeza virus (CTV) and Citrus sudden death associate virus (CSDaV), which is a member of the Genus Marafivirus, Famíly Tymoviridae. Due to this, it is necessary to separate these pathogens, in order to complete Kochs postulated for the CSDaV. The main purpose of the present work was to try to isolate the CSDaV to verify its role on CSD disease. In addition, attempts were done to purify the virus and produce polyclonal antiserum for disease diagnosis. Purification was carried out as described for Potato leaf roll virus, but results were not suitable due to the constant presence of CTV. Efforts to remove CTV by immunoprecipitation with homologous antiserum did not succeed. The produced antiserum reacted indistinctly with extracts of plants infected with both viruses. SCDaV was mechanically transmitted to Nicotiana sp., N. clevelandii, Chenopodium amaranticolor, and C. quinoa, causing mainly local infection. Infection was confirmed by RT-PCR and virus identity was determined by nucleotide sequence of the amplified fragment. Efforts to transmit CSDaV, using as inoculum extract from field infected plants, by means of Cucucuta sp., by incisions on the trunk of the test-plants, with Toxoptera citricida apparently viruliferous only for the tymovirus, and by means of citrus seed inoculation gave negative results.

A energia radiante absorvida pelas copas tem aplicação em estudos de fotossíntese e transpiração de plantas arbóreas. Sua determinação não é simples. Nas últimas duas décadas tem sido realizados trabalhos sobre interceptação de radiação por espécies arbóreas isoladas ou em renques, envolvendo tanto radiação de ondas curtas como de ondas longas (saldo de radiação, Rn). Uma técnica de medida de Rn utiliza radiômetros movendo-se em torno da copa de uma árvore (geometria esférica de medida) ou ao longo de copas de um renque (geometria cilíndrica). Uma alternativa é o uso de modelagem físico-matemática para estimativa de Rn, que também exige medidas para testar modelos. Considerando os poucos trabalhos nessa linha de pesquisa, o presente estudo objetivou: a) avaliar o desempenho de sistemas móveis de integração espaçotemporal de medidas de Rn em renque de um cafezal e de um pomar de limeira ácida localizados no Campus Luiz de Queiroz, USP, Piracicaba, SP; b) estabelecer relações do saldo de radiação das copas de cafeeiros (Rnc) e limeiras ácidas (Rnl) com o saldo de radiação de gramado (Rng) e irradiância solar global (Rg); c) avaliar o desempenho de três modelos físicomatemáticos de estimativa de Rn por comparação com as medidas realizadas com varredura da copa pelos saldo-radiômetros movimentando-se ao longo dos renques (geometria cilíndrica de medidas). Os estudos foram realizados nas quatro estações do ano e em três no pomar, iniciandose respectivamente no outono e no verão de 2008. Os sistemas integradores forneceram valores diários de magnitude coerentes com os de calor latente de vaporização da copa determinados por medidas de transpiração de uma árvore. O desempenho do sistema de grande porte utilizado no pomar exige testes adicionais. O curso diário de Rn em cada posição dos radiômetros em torno da copa mostraram padrões diferenciados conforme orientação do renque e época do ano. No cafezal foram encontradas muito boas relações de Rnc com Rg e Rng nas escalas de 15min, horária e diurna, exceto no verão para 15min e horária e no inverno, na escala diurna, para Rng. Para o pomar, as relações de Rnl com Rg e Rng foram boas nas três escalas temporais, exceto no verão para 15min e horária e no outono na escala diurna. Para o cafezal o modelo de Beer apresentou altos índices de confiabilidade nas épocas do ano, nas escalas horária e diurna; e no pomar se mostrou confiável para inverno, mas não no verão na escala diurna e na escala horária apresentou menor confiabilidade. O modelo de Pilau apresentou boa confiabilidade para o cafezal no outono e menor confiabilidade nas demais estações, enquanto na escala horária verificou-se boa confiabilidade no outono e inverno; para o pomar, o desempenho foi satisfatório para inverno nas duas escalas temporais e insatisfatório para verão na escala diurna. Para o cafezal o modelo de Oyarzun mostrou-se confiável na escala diurna, e menos confiável na escala horária no verão; para o pomar, apresentou boa confiabilidade em ambas escalas temporais no inverno e baixa confiabilidade no verão. / The amount of radiant energy absorbed by the canopy of trees has great application in photosynthesis and transpiration research. Studies of radiation interception by the canopies of an isolated or a sequence of trees in hedgerows have been carried out by a technique which employs moving radiometers around an isolated tree (spherical geometry of measurement) or along a part of a hedgerow (cylindrical geometry). This technique allows spatiotemporal integration of the values. Crop Modeling is an alternative approach to estimate the radiation balance of canopies (Rn). The present study had the following objectives: a) to evaluate the performance of systems for spatiotemporal integration of Rn measurements in hedgerows of a coffee and an acid lime crops at the Luiz de Queiroz Campus of the University of São Paulo, in Piracicaba, SP, Brazil; b) to establish relations of the net radiation of the coffee (Rnc) and of acid lime plants (Rnl) canopies with grass net radiation (Rng) and incoming solar radiation (Rg); c) to evaluate the performance of three models of Radiation Balance (Rn), by comparing modem results with measurements by the moving radiometers along the planting row (cylindrical geometry). The coffee experiment was carried out all year long starting in the fall of 2008 while for the orchard only three seasons were tested starting in the summer 2008. Measurements of Rn by the moving systems were considered reliable, but it is recommended further testing of that of the orchard. The daily course of Rn for each measurement around the canopy showed different patterns for the two crops, in agreement with planting row orientation and season. Concerning to relations of Rnc with Rg and Rng integrated for 15min, hourly and diurnal periods, they were very good for the coffee crop in the three timescales, excepting for the 15min and hourly timescales in the summer and for the Rng for the diurnal period in the winter. For the orchard, the relations of Rnl with Rg and Rng were good, excepting for the summer in the 15min and hourly and in autumn for the diurnal timescales. The Beer´s model showed good reliability for the coffee crop; while for the orchard it showed to be reliable in the winter, but not in the summer for the diurnal period; for the hourly periods it was less reliable. The Pilau´s model showed good reliability for the coffee crop for both the diurnal and hourly periods during the fall, but less reliability in the other seasons; for the orchard, its performance was reliable for the winter in the two timescales and not reliable for the summer in the diurnal scale. The Oyarzun´s model showed to be reliable in the diurnal timescale and less reliable in the hourly timescale for the summer; for the orchard, it showed good reliability for the winter and little reliability for the summer.