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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Cultivares de café Conilon (Coffea Canephora) sob estresse salino-hídrico /

Temóteo, Amansleone da Silva, 1973- January 2012 (has links)
Orientador: Antônio de Pádua Souza / Banca: Célia Regina Lopes Zimback / Banca: Raimundo Leite Cruz / Banca: Carmen Silvia Fernandes Boaro / Banca: José Francismar de Medeiros / Resumo: A cafeicultura expandiu-se para áreas consideradas pouco aptas ao seu desenvolvimento e o cafeeiro Conilon tem apresentado características de adaptações para tais áreas. Nessas áreas, a salinidade aliada à deficiência hídrica apresentam restrições para cultivos de certas espécies ou cultivar, interferindo no crescimento e desenvolvimento de culturas comerciais. O objetivo deste estudo foi avaliar de forma comparativa os efeitos da salinidade aliada à disponibilidade hídrica do solo, em cultivares de café Conilon na fase inicial de crescimento, por meio de variáveis fisiológicas e nutricionais. O experimento foi desenvolvido em ambiente protegido em área experimental do Departamento de Engenharia Rural da FCA- UNESP, Botucatu-SP, no delineamento estatístico de blocos casualizados com duas cultivares de Conilon (clones 120 e 14), quatro níveis de salinidade no solo (0,0; 2,0; 4,0 e 6,0 dS m-1) e dois teores de água no solo (50% e 70% da água disponível no solo - AD), com 4 repetições, totalizando 64 parcelas, com um vaso e uma planta. Aos 165 dias, as mudas foram transplantadas para vasos com capacidade de 10 litros, mantidas com teor de água no solo próximo a capacidade de campo por 15 dias. Atingindo os níveis... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Coffee production has expanded to areas considered unsuitable to its development. Conilon coffee plant has shown adaptation characteristics for such areas where salinity combined to water deficit restrict crops of certain species or cultivar, interfering in the growth and development of commercial crops. This study aimed to compare the effects of salinity and soil water availability on Conilon coffee cultivars in the initial phase of the development through physiological and nutritional variables. The experiment was carried out in a protected environment of an experimental area of the Department of Rural Engineering of FCA-UNESP, Botucatu-SP, in a random block statistical design with two Conilon cultivars (clones 120 and 14), four levels of soil salinity (0.0; 2.0; 4.0 and 6.0 dS m-1) and two water contents in the soil (50% and 70% of available water in the soil - AW) and four replications, totalizing 64 plots with a vase and a plant. At 165 days, the seedlings were transferred to 10-liter vases, and the soil water content was kept almost at field capacity for 15 days. The vases were weighed daily, and water was replaced until pre-determined levels when they reached (50% and 70% of AW). Growth evaluations (leaf area, stem diameter and stem height) were done at (0, 20, 40, 60, 80, 100, 120, 140, 160 and 180 days), and 20 days after the differentiation of water treatments (DAT) in the soil, measurements were done. For relative water content and leaf water potential, (30, 60, 90, 120, 150 and 180 DAT) were taken into consideration. At the end of the experiment (180 DAT), the number of plagiotropic branches was counted; and at the time of the experiment, expanded leaves of the medial region were collected for the... (Complete abstract click electronic access below) / Doutor
32

Resposta varietal da cana-de-açúcar à deficiência hídrica, durante o desenvolvimento inicial em um latossolo vermelho distroférrico /

Holanda, Lucas Almeida de, 1987. January 2012 (has links)
Orientador: Antônio de Pádua Sousa / Coorientador: Marcelo de Almeida Silva / Banca:Roberto Lyra Villas Bôas / Banca: Maritane Prior / Resumo: Devido ao aumento na demanda por etanol combustível, principalmente por causa dos veículos bicombustível, há uma expansão das áreas cultivadas com cana-de-açúcar para ambientes menos favoráveis para o desenvolvimento da cultura, com períodos de déficit hídrico maiores e mais intensos. O estresse hídrico está entre os fatores que mais limitam o crescimento e a produtividade agrícola. Mesmo a cana-de-açúcar sendo uma cultura com resistência moderada à seca, tem grandes perdas de produtividade por causa da mesma. Por isso, a seleção de genótipos tolerantes ao déficit hídrico pode representar uma alternativa para diminuir a quantidade de água utilizada na irrigação, mantendo ou aumentando a produtividade. Esse trabalho foi desenvolvido com o objetivo de conhecer o comportamento de quatro cultivares de cana-de-açúcar durante o desenvolvimento inicial, sob condições de deficiência hídrica, por meio de variáveis morfológicas e fisiológicas, visando auxiliar na seleção de genótipos mais tolerantes à seca no sentido de promover diminuição de gastos com irrigação sem prejuízos econômicos à cultura. O experimento foi conduzido em casa de vegetação, no Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas - UNESP/Botucatu - SP, entre os dias 26/11/2010 a 05/04/2011. Foram avaliadas quatro cultivares de cana-de-açúcar (RB855453, RB92579, RB965902 e RB965917), em seu desenvolvimento inicial, em um tratamento controle (100% da capacidade de campo) e com déficit hídrico (50% da capacidade de campo). As avaliações foram feitas em três datas diferentes (0, 28 e 63 dias após a aplicação do tratamento). Foram analisadas variáveis morfológicas: altura da planta; área foliar; comprimento da folha; largura da folha; número de folhas verdes, variáveis fisiológicas: conteúdo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Due to increase in demand for ethanol fuel, mainly because of the flex-fuel vehicles, there is an expansion of areas planted with sugarcane to less favorable environments for the crop development, with major and more intense episodes of drought. Water stress is among the factors that limit growth and agricultural productivity. Even the sugarcane being a crop with moderate resistance to drought, it has high yield losses because of it. Therefore, the selection of tolerant genotypes to water stress may represent an alternative to reduce the amount of water used for irrigation, while maintaining or increasing productivity. This work was developed in order to understand the behavior of four sugarcane cultivars during the initial development under water stress conditions by means of morphological and physiological variables, aiming the selection of tolerant genotypes to drought to promote reduction of spending on irrigation without economic damage to the crop. The experiment was carried out in a greenhouse at the Department of Rural Engineering, College of Agricultural Sciences - UNESP / Botucatu - SP, between 11/26/2010 to 04/05/2011. We evaluated four sugarcane varieties (RB855453, RB92579, RB965902 and RB965917) in its initial development under two treatments, i.e., in a control (100% of field capacity) and drought (50% of field capacity). Evaluations were made on three different dates (0, 28 and 63 days after treatment application). The morphological variables plant height, leaf area, leaf length, leaf width, number of green leaves, and the physiological variables total chlorophyll content, chlorophyll content through SPAD index, leaf water potential, stomatal conductance, maximum quantum yield of PSII, as well dry matter production of shoots and roots were analyzed. The cultivars RB855453 and RB92579 had better results of dry... (Complete abstract click electronic access below) / Mestre
33

Irrigação deficitária em videira de vinho cv. Syrah durante o período chuvoso no semiárido /

Correia, Joselina de Souza, 1978. January 2012 (has links)
Orientador: Luís Henrique Bassoi / Banca: Raimundo Leite Cruz / Banca: Antonio Odair Santos / Resumo: As disponibilidades de radiação solar e de água para irrigação contribuem para a produção de uvas ao longo do ano no Vale do Submédio São Francisco. Diante da expansão da vitivinicultura nesta região, a demanda por pesquisas em relação ao manejo adequado e prático da videira para a região semiárida brasileira tem aumentado. Desta forma, o presente trabalho teve o objetivo de avaliar a influência de estratégias de irrigação na cultura da videira de vinho, e suas possíveis influências na produtividade e qualidade das uvas. O experimento foi conduzido na Embrapa Semiárido, em Petrolina -PE, entre 10 de novembro de 2010 a 28 de fevereiro de 2011, com a videira cv. Syrah/Paulsen 1103, plantada em espaçamento de 1 x 3 m, em um Argissolo Vermelho Amarelo Eutrófico Latossólico. O sistema de irrigação utilizado foi o gotejamento, com emissores espaçados em 0,5 m na linha de plantio, com vazão de 2,5 L.h-1. O delineamento utilizado foi o de blocos casualizados, com 3 tratamentos e 4 repetições. Os tratamentos foram: 1- irrigação plena (IP), irrigação realizada com base na reposição da evapotranspiração da cultura (ETc), durante todo o ciclo de produção; 2 - irrigação com déficit controlado (IDC), irrigação interrompida aos 65 dias após a poda de produção (dapp), porém com irrigações aos 91, 92 e 93 dapp; e 3 - irrigação deficitária (ID), irrigação interrompida aos 65 dapp até a colheita aos 110 dapp. A ETc foi estimada pela relação entre evapotranspiração de referência (ETo), e o coeficiente de cultura (Kc). O potencial hídrico foliar (Ψfoliar) foi medido em cada tratamento, do estádio fenológico de maturação até o estádio de cachos maduros. Durante o experimento, ocorreu uma precipitação total de 252 mm. A ETc durante... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The availability of solar radiation and water for irrigation contribute to the wine grape production throughout the year in the Lower Middle São Francisco Valley. In consequence of increase of vine growing area in this region, the research demand about suitable and feasible vine water management in the Brazilian semi-arid region has increased. Thus, this study aimed to evaluate the influence of irrigation strategies in vineyards, and their possible effects on yield and quality of wine grapes. The experiment was carried out at Embrapa Tropical Semi-arid, in Petrolina, State of Pernambuco, Brazil, from November 10, 2010, to February 28, 2011. The grapevive cv. Syrah, grafted on Paulsen 1103, was planted at a spacing grid of 1 x 3 m, in a Argissolo Vermelho Amarelo Eutrófico Latossólico. Drip irrigation was used, with emitters spaced 0.5 m within the plant row, with 2.5 L.h-1 flow. The design was a randomized complete block with three treatments and four replications. The treatments were: 1 - full irrigation (FI), where irrigation was performed based on crop evapotranspiration (ETc, mm) during all growing season, without water restriction to the vines; 2 - regulated deficit irrigation (RDI), where irrigation was performed based on ETc until 65 days after pruning (dap), but performed at 91, 92, and 93 dap and 3 - deficit irrigation (ID) - where irrigation interrupted at 65 dap until harvest at 110 dap. The ETc was estimated by the relationship between reference evapotranspiration (ETo), and crop coefficient (kc) for each phenological phase of vine. The leaf water potential (Ψpd) was measured... (Complete abstract click electronic access below) / Mestre
34

Os efeitos do estresse hídrico na cultura da soja (Glycine Max, (L.) Merrill.) / The effects of water stress in soybean (Glycine max (L.) Merrill.)

Ricardo Gava 27 June 2014 (has links)
O Brasil é o segundo maior produtor mundial de Soja e as áreas de plantio se localizam em regiões com os mais diversos regimes pluviais. Esse trabalho estudou os efeitos do estresse hídrico na cultura da soja, causados pela falta de água e pelo excesso, ocorrendo tanto no ciclo total como individualmente nas fases mais importantes. O experimento foi conduzido no Departamento de Engenharia de Biossistemas, da Escola Superior de Agricultura \"Luiz de Queiroz\" - ESALQ/USP, em Piracicaba - SP, no período de Dezembro de 2011 à Março de 2013, tendo sido realizadas duas safras de soja (Safra 2011/2012 e Safra 2012/2013). Foi utilizada a cobertura de uma casa de vegetação, equipada com 48 caixas com controle de drenagem, de 1,1 m de largura por 1,3 m de comprimento e 0,75 m de profundidade. A Evapotranspiração de Referência (ETo) foi calculada pelo método de Penman Montheith - FAO. O delineamento experimental foi em blocos casualizados com 4 repetições. Para aplicação dos tratamentos o ciclo da cultura foi dividido em 4 subperíodos: S1(Desenvolvimento Vegetativo); S2 (Floração à Início da Frutificação); S3 (Completa Formação de Vagens à Formação da Produção); S4 (Maturação). Na Safra 2011/2012, a cultivar utilizada foi a EMBRAPA BRS 316-RR (V1). O plantio foi realizado em 12 Dezembro de 2011 e a colheita em 10 de Abril de 2012. Os tratamentos constaram de 3 lâminas de irrigação: Déficit (50% da ETc); Excesso (150% da ETc) e Irrigação Plena (100% da ETc) variando em 12 diferentes formas de ocorrência: Déficit no ciclo total, Déficit no S1, Déficit no S2, Déficit no S3, Déficit no S4, Excesso no ciclo total, Excesso no S1, Excesso no S2, Excesso no S3, Excesso no S4 e Irrigação Plena (IP). Quando não estavam passando pelo subperíodo de aplicação do tratamento, a parcela era irrigação com irrigação plena. O excesso não foi prejudicial para nenhuma das variáveis analisadas. Já o déficit aplicado na fase de enchimento de grãos resultou em perdas significativas de produtividade. Já na safra 2012/2013, a cultivar de soja utilizada foi a BMX POTÊNCIA RR (V2). O plantio foi realizado em 06 de novembro de 2012 e a colheita em 08 de março de 2013. Nesse caso os tratamentos constaram de 4 lâminas de irrigação (30, 50, 100 e 150% da ETc) aplicadas em cada um dos 4 subperíodos da cultura. O déficit de 50% (moderado) foi chamado de D1 e o déficit de 70% (Severo) foi chamado de D2. Assim, os tratamentos com 50% de déficit ocorrendo nos 4 subperíodos e no Ciclo Total (CT) foram: D1S1V2, D1S2V2, D1S3V2, D1S4V2, D1CTV2. Da mesma forma os tratamentos com déficit de 70% foram chamados de: D2S1V2, D2S2V2, D2S3V2, D2S4V2 e D2CTV2. Houve ainda um tratamento com excesso (150% da ETc) chamado de E1CTV2 e o tratamento testemunha com irrigação plena (IPCTV2). Os resultados mostraram que as lâminas de déficit reduziram a produtividade quando aplicadas no ciclo todo. Porém, quando aplicadas somente em subperíodos, não apresentaram diferenças significativas em relação à irrigação plena. / Brazil is the second largest producer of soybean and its plantation areas are located in regions with very different rainfall patterns. Thus, this study aimed to study the effects of water stress in soybean, caused by lack of water and excess, occurring both in the total cycle as individually in the most important stages of the culture. The experiment was conducted in the Biosystems Engineering Department, \"Luiz de Queiroz\" College of Agriculture - ESALQ / USP, in Piracicaba - SP, in the period of December 2011 to March 2013, two crops of soybeans have been harvested (2011/2012 harvest and 2012/2013 harvest). Covering a greenhouse equipped with 48 boxes with controlled drainage, 1.1 m wide by 1.3 m long and 0.75 m deep was used. The reference evapotranspiration (ETo) was calculated by Penman Montheith - FAO. The experiment was done in randomized blocks design with 4 replications. For the application of the treatments, the crop cycle was divided into four sub-periods: S1 (All of Vegetative Stage); S2 (Beginning Bloom until Full Pod); S3 (Beginning Seed until Full Seed); S4 (Beginning Maturity until Full Maturity). In 2011/2012 harvest, the cultivar was BRS 316 EMBRAPA - RR (V1). The planting was done on December 12, 2011, and harvested in April 10, 2012. The treatments consisted of three irrigation levels, Deficit (50% ETc); Excess (150% ETc) and Full irrigation (100% ETc) ranging in 12 different forms of occurrence: Deficit in total cycle; Deficit only in S1; Deficit only in S2; Deficit only in S3; Deficit only in S4; Excess in total cycle; Excess only in S1; Excess only in S2, Excess only in S3; Excess only in S4 and Full Irrigation. When they were not passing through the sub period of application of the treatment, the plot was irrigation with full irrigation. Excess was not detrimental to any of the variant. However the deficit applied during grain filling resulted in significant productivity losses. As for the 2012/2013 harvest, the soybean variety used was BMX POTEMCIA RR (V2). The planting was done in November 6, 2012, and the harvest in March, 8, 2013. In this case the treatments consisted of four irrigation levels (30, 50, 100 and 150% of ETc) applied in each one of the four sub-periods of culture. The deficit of 50% (moderate) was called D1 and the deficit of 70% (Severe) was called D2. Thus, treatments with 50% deficit occurring in 4 subperiods and Full Cycle (CT) were: D1S1V2, D1S2V2, D1S3V2, D1S4V2, D1CTV2. Likewise, the treatments with 70% deficit were called: D2S1V2, D2S2V2, D2S3V2, D2S4V2 and D2CTV2. There was also a treatment with excess (150% ETc) called E1CTV2 and control treatment with Full irrigation (IPCTV2). The results showed that the water depths of Deficit reduced productivity when applied in full cycle. However, when applied only in subperiods showed no significant differences compared to full irrigation.
35

Environmental and management impacts in turfgrass systems: nitrous oxide emissions, carbon sequestration, and drought and traffic stress

Braun, Ross Charles January 1900 (has links)
Doctor of Philosophy / Department of Horticulture and Natural Resources / Dale J. Bremer / Turfgrasses sequester and emit carbon dioxide, and emit nitrous oxide (N₂O) when fertilized with nitrogen and irrigated. Future water availability is a serious issue and drought restrictions may be imposed on turf managers while turf areas are subjected to traffic stress. My objectives in Chapter 2 were to: 1) quantify the magnitude and patterns of N₂O emissions and carbon (C) sequestration in zoysiagrass (Zoysia japonica Steud.); and 2) determine how irrigation (66% and 33% reference evapotranspiration [ET₀] replacement) and fertilization (polymer-coated urea, urea, and unfertilized) management may reduce N₂O emissions and enhance carbon sequestration. My objectives in Chapters 3 and 4 were to evaluate above- and below-ground responses of cool-season (C3) [Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.)] and warm-season (C4) grasses {buffalograss [Buchloe dactyloides (Nutt.) Engelm] and zoysiagrass] at golf course-related mowing heights [1.6-cm (fairway) and 6.4-cm (rough)], with and without traffic during a simulated drought and subsequent recovery period (without traffic). In Chapter 2, N₂O emissions increased by 6.3% with more irrigation during summers and increased from 4.06 kg ha⁻¹ in unfertilized turf to 4.50, and 5.62 kg ha⁻¹ in polymer-coated urea and urea treated turf, respectively, during the 2-year study. There was no difference in C sequestration rates between a high vs. low input management schedule. The C sequestration rate was 0.952 Mg C ha⁻¹ yr⁻¹ for zoysiagrass when averaged across management schedules and depths. The use of a controlled-release fertilizer such as PCU compared to the use of a quick-release fertilizer and/or lower irrigation will reduce N₂O emissions in turfgrass. In Chapters 3 and 4, the better drought tolerance of C4 grasses led to more differences between traffic treatments within C4 than C3 grasses, but C4 grasses maintained the highest quality and green cover. Quality at rough- compared to fairway-height was more impacted by traffic. Decreasing soil moisture due to drought led to a minimal impact from traffic on soil bulk density, soil penetration resistance (SPR), and root measurements. During drought, SPR at deeper soil depths and fairway plots increased and exceeded the critical value of 2.0 MPa. Both C4 grasses and perennial ryegrass had larger root diameters, which may have led to better soil compaction resistance. Traffic during drought will have a negative and accelerated impacts above-ground, but minimal impact below-ground, which will vary with turf species and mowing height.
36

Evapotranspiração da cana-de-açúcar e fotossíntese acumulada em biomassa e energia, para diferentes variedades, disponibilidades hídricas no solo e ciclos de cultivos / Sugarcane evapotranspiration and accumulated photosynthesis into biomass and energy, for different varieties, soil water availability and crop cycles

Leal, Daniel Philipe Veloso 21 June 2012 (has links)
O objetivo neste experimento foi quantificar a evapotranspiração de diferentes variedades de cana-de-açúcar, a produtividade de biomassa e energia (fotossíntese acumulada), bem como a produtividade da água (PA), submetidas à irrigação plena e sob déficit, durante o estádio de enchimento e crescimento dos colmos, em três ciclos de cultivo sequenciais (2009, 2010 e 2011). Dois experimentos nomeados Experimento 1 e Experimento 2 foram instalados e desenvolvidos em casa de vegetação, com 23 variedades, em vasos com volume de 0,5 m3. No Experimento 1 foram avaliadas 9 variedades, sendo elas RB855453, RB855536, RB925211, RB867515, SP89-1115, SP81-3250, CTC14, CTC8 e CTC6 implantadas em um solo de textura argilosa, classificado como Nitossolo Vermelho Eutrófico. Outras 14 variedades (RB925345, RB855156, RB966928, RB72454, RB92579, IACSP95-5000, Caiana, SP83-2847, SP90-3414, SP79-1011, CTC17, CTC15, CTC9 e CTC2) foram implantadas no Experimento 2 em um solo de textura franco-arenosa, classificado como Latossolo Vermelho Amarelo. Em ambos os experimentos as variedades foram submetidas à irrigação plena e à irrigação sob déficit. O manejo da irrigação foi realizado através de irrigação por gotejamento mediante controle do potencial mátrico, via tensiômetros instalados em diferentes profundidades. Em todos os ciclos e para cada variedade e cada tipo de manejo da irrigação (com e sem déficit), foram avaliadas a biomassa fresca de colmo (BFC), os parâmetros tecnológicos, o rendimento bruto de açúcar (RBA), a fotossíntese acumulada (biomassa seca da parte aérea), a energia total da biomassa (ET) e a produtividade da água da BFC, do RBA e da ET. Os fatores que mais influenciaram na fotossíntese acumulada (biomassa e energia), e consequentemente na produtividade da água durante os três ciclos de cultivos nas variedades estudadas foram a radiação e a disponibilidade hídrica no solo. A produtividade da água em BFC (PABFC) no solo de textura argilosa atingiu valor máximo de 29,10 Kg.m-3 na variedade CTC6, sob irrigação plena e mínimo de 11,50 Kg.m-3 na variedade RB855536 em condições de déficit. A produtividade da água em biomassa de rendimento bruto de açúcar (PARBA) variou de 1,44 a 3,52 Kg.m-3. A produtividade da água em energia total (PAET), no solo de textura argilosa alcançou melhor resultado na variedade SP81-3250 com 176,32 MJ.m-3. No solo de textura franco-arenosa a PABFC variou de 8,13 a 26,39 K.m-3, na PARBA a variação foi de 0,99 a 3,42 Kg.m-3 e na PAET a variação foi de 64,89 a 192,92 MJ.m-3. / The objective of this experiment was to quantify evapotranspiration in different varieties of sugar cane, biomass productivity and energy (accumulated photosynthesis), biomass productivity and energy as well as the water productivity, subjected to full and deficit irrigation, for three sequential crop cycles (2009, 2010 and 2011). Two experiments named Experiment 1 and Experiment 2 were installed and developed under greenhouse conditions, , with 23 varieties planted in vases with volume of 0.5 m3. In the Experiment 1 were evaluated nine varieties: RB855453, RB855536, RB925211, RB867515, SP89-1115, SP81-3250, CTC14, CTC8, CTC6, and implanted in clay texture soil, classified as Nitossolo Vermelho Eutrófico. Other 14 varieties (RB925345, RB855156, RB966928, RB72454, RB92579, IACSP95- 5000, Caiana, SP83-2847, SP90-3414, SP79-1011, CTC17, CTC15, CTC9 and CTC2) were implanted in Experiment 2 in the sandy loam soil texture, classified as Latossolo Vermelho Amarelo. In both experiments the varieties were subjected to full irrigation and deficit irrigation. The water management was accomplished through trickle irrigation system by monitoring tensiometers installed at different depths. In all cycles and for each variety and each type of irrigation management (with and without deficit) were evaluated stems fresh biomass, technological parameters, sugar gross yield, the cumulative photosynthesis (shoot dry biomass), biomass total energy and water productivity of the stems fresh biomass, of the sugar gross yield and of the total energy. The factors that most influenced the cumulative photosynthesis (biomass and energy), and consequently the water productivity during crop three cycles in varieties studied were radiation and water supply. The water productivity in stems fresh biomass in clay texture soil reached a maximum of 29.10 kg.m-3 in the variety CTC6 under full irrigation, and minimum of 11.50 kg.m-3 in the variety RB855536 in deficit conditions. The water productivity in biomass of sugar gross yield ranged from 1.44 to 3.52 Kg.m-3. The water productivity in total energy, in clay soil achieved better result in the variety SP81-3250 with 176.32 MJ.m-3. In sandy loam soil the water productivity of stem fresh biomass varied from 8.13 to 26.39 Kg.m-3, in water productivity of sugar gross yield the variation was 0.99 to 3.42 Kg.m-3 and in the water productivity of total energy the variation was 64.89 to 192.92 MJ.m-3.
37

Qualidade das mudas clonais de dois híbridos de eucalipto em função do manejo hídrico

Garcia, Rodolfo D’Aloia [UNESP] 23 August 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-23Bitstream added on 2014-06-13T21:00:52Z : No. of bitstreams: 1 garcia_rd_me_botfca.pdf: 728744 bytes, checksum: 4e020da519ee70d29e2ebfa30b7c2d97 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No Brasil observa-se que o cultivo do eucalipto contribui expressivamente na economia nacional, isso se dá em decorrência de elevadas taxas de produtividade das florestas existentes no território nacional. Analisando então, uma floresta produtiva se inicia através de mudas com boa qualidade morfológicas e resistentes às adversidades fisiológicas apresentadas pelo meio, para se definir como sendo de boa qualidade uma série de fatores são considerados essenciais no processo de produção desta muda, e o manejo hídrico é um fator primordial a ser analisado. Os estudos sobre manejo hídrico em viveiros de produção são escassos e desatualizados em decorrência das diversas descobertas no âmbito clonal de produção de mudas. Neste sentido o trabalho teve por objetivo verificar a influência da lâmina e a frequência de irrigação, aplicadas as mudas de Eucalyptus grandis vs. Eucalyptus urophylla em ambiente controlado, com o foco final na formação de uma muda de melhor qualidade para as mais diversas necessidades do mercado florestal. O experimento foi conduzido no Viveiro do Departamento de Recursos Naturais/Setor de Ciências Florestais, na Fazenda Experimental Lageado, pertencente à Faculdade de Ciências Agronômicas (FCA) da UNESP, no município de Botucatu – SP. O trabalho constituiu-se de dois experimentos sendo um com o clone 144 (mais resistente ao déficit hídrico) e o outro com o clone 103 (mais suscetível ao déficit hídrico). O substrato utilizado foi o produto comercial denominado Carolina Soil Florestal®. O delineamento estatístico foi um fatorial (3x2) inteiramente casualizado constituído dos seguintes fatores: 2 frequências de irrigação (2 e 5 vezes ao dia) e 3 lâminas brutas de irrigação (8, 12 e 16 mm). O experimento foi composto por 06 tratamentos, cada qual composto por... / In Brazil we found that each passing day the national economy depends on the cultivation of eucalyptus. Thus a productive forest comes from a good quality seedlings. This study aimed to investigate the influence of intensity and frequency of irrigation applied to seedlings of Eucalyptus grandis vs. Eucalyptus urophylla in a controlled environment with a focus on the formation of a final change to better quality, both in nursery and field workers. The experiment was conducted in the Nursery Department of Natural Resources / Division of Forest Science at the Experimental Farm Lageado belonging to the Faculdade de Ciências Agronômicas (FCA) of UNESP, Botucatu - SP. The substrate used was a commercial product called Carolina Forest Soil. The design was a factorial (3x2x2) randomized consists of the following factors: 3 intensity of irrigation (8, 12 and 16 mm), two irrigation frequencies (2 and 5 x day), two hybrid clones of Eucalyptus grandis vs. Eucalyptus urophylla. The experiment consisted of 12 treatments, each treatment with 04 replications, each consisting of 48 plants (24 plants useful per plate), totaling 96 plants per treatment. The seedling were evaluated as: aerial part height (H); diameter of collect (DC); aerial part... (Complete abstract click electronic access below)
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Evapotranspiração da cana-de-açúcar e fotossíntese acumulada em biomassa e energia, para diferentes variedades, disponibilidades hídricas no solo e ciclos de cultivos / Sugarcane evapotranspiration and accumulated photosynthesis into biomass and energy, for different varieties, soil water availability and crop cycles

Daniel Philipe Veloso Leal 21 June 2012 (has links)
O objetivo neste experimento foi quantificar a evapotranspiração de diferentes variedades de cana-de-açúcar, a produtividade de biomassa e energia (fotossíntese acumulada), bem como a produtividade da água (PA), submetidas à irrigação plena e sob déficit, durante o estádio de enchimento e crescimento dos colmos, em três ciclos de cultivo sequenciais (2009, 2010 e 2011). Dois experimentos nomeados Experimento 1 e Experimento 2 foram instalados e desenvolvidos em casa de vegetação, com 23 variedades, em vasos com volume de 0,5 m3. No Experimento 1 foram avaliadas 9 variedades, sendo elas RB855453, RB855536, RB925211, RB867515, SP89-1115, SP81-3250, CTC14, CTC8 e CTC6 implantadas em um solo de textura argilosa, classificado como Nitossolo Vermelho Eutrófico. Outras 14 variedades (RB925345, RB855156, RB966928, RB72454, RB92579, IACSP95-5000, Caiana, SP83-2847, SP90-3414, SP79-1011, CTC17, CTC15, CTC9 e CTC2) foram implantadas no Experimento 2 em um solo de textura franco-arenosa, classificado como Latossolo Vermelho Amarelo. Em ambos os experimentos as variedades foram submetidas à irrigação plena e à irrigação sob déficit. O manejo da irrigação foi realizado através de irrigação por gotejamento mediante controle do potencial mátrico, via tensiômetros instalados em diferentes profundidades. Em todos os ciclos e para cada variedade e cada tipo de manejo da irrigação (com e sem déficit), foram avaliadas a biomassa fresca de colmo (BFC), os parâmetros tecnológicos, o rendimento bruto de açúcar (RBA), a fotossíntese acumulada (biomassa seca da parte aérea), a energia total da biomassa (ET) e a produtividade da água da BFC, do RBA e da ET. Os fatores que mais influenciaram na fotossíntese acumulada (biomassa e energia), e consequentemente na produtividade da água durante os três ciclos de cultivos nas variedades estudadas foram a radiação e a disponibilidade hídrica no solo. A produtividade da água em BFC (PABFC) no solo de textura argilosa atingiu valor máximo de 29,10 Kg.m-3 na variedade CTC6, sob irrigação plena e mínimo de 11,50 Kg.m-3 na variedade RB855536 em condições de déficit. A produtividade da água em biomassa de rendimento bruto de açúcar (PARBA) variou de 1,44 a 3,52 Kg.m-3. A produtividade da água em energia total (PAET), no solo de textura argilosa alcançou melhor resultado na variedade SP81-3250 com 176,32 MJ.m-3. No solo de textura franco-arenosa a PABFC variou de 8,13 a 26,39 K.m-3, na PARBA a variação foi de 0,99 a 3,42 Kg.m-3 e na PAET a variação foi de 64,89 a 192,92 MJ.m-3. / The objective of this experiment was to quantify evapotranspiration in different varieties of sugar cane, biomass productivity and energy (accumulated photosynthesis), biomass productivity and energy as well as the water productivity, subjected to full and deficit irrigation, for three sequential crop cycles (2009, 2010 and 2011). Two experiments named Experiment 1 and Experiment 2 were installed and developed under greenhouse conditions, , with 23 varieties planted in vases with volume of 0.5 m3. In the Experiment 1 were evaluated nine varieties: RB855453, RB855536, RB925211, RB867515, SP89-1115, SP81-3250, CTC14, CTC8, CTC6, and implanted in clay texture soil, classified as Nitossolo Vermelho Eutrófico. Other 14 varieties (RB925345, RB855156, RB966928, RB72454, RB92579, IACSP95- 5000, Caiana, SP83-2847, SP90-3414, SP79-1011, CTC17, CTC15, CTC9 and CTC2) were implanted in Experiment 2 in the sandy loam soil texture, classified as Latossolo Vermelho Amarelo. In both experiments the varieties were subjected to full irrigation and deficit irrigation. The water management was accomplished through trickle irrigation system by monitoring tensiometers installed at different depths. In all cycles and for each variety and each type of irrigation management (with and without deficit) were evaluated stems fresh biomass, technological parameters, sugar gross yield, the cumulative photosynthesis (shoot dry biomass), biomass total energy and water productivity of the stems fresh biomass, of the sugar gross yield and of the total energy. The factors that most influenced the cumulative photosynthesis (biomass and energy), and consequently the water productivity during crop three cycles in varieties studied were radiation and water supply. The water productivity in stems fresh biomass in clay texture soil reached a maximum of 29.10 kg.m-3 in the variety CTC6 under full irrigation, and minimum of 11.50 kg.m-3 in the variety RB855536 in deficit conditions. The water productivity in biomass of sugar gross yield ranged from 1.44 to 3.52 Kg.m-3. The water productivity in total energy, in clay soil achieved better result in the variety SP81-3250 with 176.32 MJ.m-3. In sandy loam soil the water productivity of stem fresh biomass varied from 8.13 to 26.39 Kg.m-3, in water productivity of sugar gross yield the variation was 0.99 to 3.42 Kg.m-3 and in the water productivity of total energy the variation was 64.89 to 192.92 MJ.m-3.
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Optimal irrigation scheduling under water quantity and quality constraints accounting for the stochastic character of regional weather patterns

Al-Dhuhli, Hamed Sulaiman Ali 08 February 2019 (has links)
In arid countries both water scarcity and salinity represent the key factors which drastically limit crop yield in irrigated agriculture. In addition, relatively poor management practices with pretty low water productivity (WP) seriously aggravate the situation. In order to get “more crop per drop', i.e., to substantially improve water use efficiency, this thesis proposes the novel strategy NEMO (Nested Experimental, Modeling, and Optimization Strategy) for reliably evaluating an optimal irrigation schedule. The proposed methodology relies upon a close interaction between in-depth field investigations and physically based process modeling. It is tailored specifically to fit the requirements in resource-restricted regions. Comprehensive field experiments, on site measurements as well as various laboratory analyses provide a representative database for characterizing the relevant environmental parameters as e.g. the soil properties at the considered location and the prevailing climate. A substantial part of the data obtained from the field experiments provided the input for the internationally recognized SVAT software DAISY1 or APSIM2, both physically based irrigation models which have already been successfully applied in arid regions. APSIM - which is used in the advanced parts of the study - includes not only a process based model for soil moisture transport but also a plant physiological model which describes the plant behavior under specific irrigation scenarios for a selected crop throughout a growing season. The adaption of the irrigation model to local conditions and its preliminary parameterization firstly follows available guidelines and data for areas with similar climate and soil conditions. Reference data and deterministic weather data served to build up DAISY’s basic model files. DAISY is then used within the framework of the custom made and problem oriented optimization software GET-OPTIS for evaluating the corresponding optimal irrigation schedule for a first preliminary series of experiments (IrrEx1). A second series of field experiments (IrrEx2) was accompanied by transient soil moisture measurements, which served for evaluating the soil hydraulic parameters, while the obtained yield was used for calibrating the plant physiological model of APSIM. Taking still into account the stochastic nature of weather phenomena, a stochastic optimization with GET-OPTIS was then applied not only for the traditional full irrigation but also for the most important deficit irrigation and the irrigation with saline water. The obtained optimal irrigation schedules are subsequently used for a final series of rigorous irrigation experiments (IrrEx3) which specifically focused on: (1) full irrigation for high yields with most economic water application, (2) deficit irrigation aiming at a maximum yield with only a limited amount of irrigation water, and (3) full irrigation with saline irrigation water for maximum yield. At the harvesting time, the observed crop yield and the water productivity were compared - together with other plant characteristics - with the corresponding calculated values. The agreement between calculated and measured crop data was excellent. All the field experiments have been performed following a parallel use of the common traditional FAO class A-Pan method and the novel NEMO technology. Based on the outcome of the field experiments, the NEMO applications demonstrated a striking superiority throughout all scenarios as compared to the FAO method as regards economic efficiency and sustainable use of irrigation water in both aspects water quantity and salt accumulation. Contrary to common practice, the optimal NEMO irrigation schedule - which relies on stochastic weather data - has an extended validity. Together with the use of physical data and adequate process models, the developed methodology features a highly promising potential for generalizing the experimental findings for other, environmentally similar, regions. NEMO thus opens wide possibilities for a cost effective and sustainable long-term application to other arid or semi-arid areas.
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Regulated deficit irrigation in citrus: agronomic response and water stress indicators

Ballester Lurbe, Carlos 06 May 2013 (has links)
In the Mediterranean area water is a scarce natural resource and periods of drought are frequent. It is then important to increase water use efficiency of irrigated crops. In order to achieve this, one promising option is regulated deficit irrigation (RDI). RDI consists in reducing water application during stages of crop development when yield and fruit quality have low sensitivity to water stress. Full irrigation is provided during the rest of the season to maintain production and fruit quality at adequate levels (Behboudian and Mills, 1997). In citrus, flowering and fruit set are sensitive periods to water restrictions, because water stress during this period increases fruit drop (Ginestar and Castel 1996). The more appropriate phenological period for applying water restrictions seems to be the summer period providing that water applications returned at full dosage sufficiently before harvest in order to allow for compensation in fruit growth (Cohen and Goell 1988). Previous work by González-Altozano and Castel (1999) showed the feasibility of applying RDI in 'Clementina de Nules' and identified threshold values of plant water stress that allowed water savings of about 10-20% without any detrimental effect on yield or fruit size. It would be desirable now to study the extrapolation of these results to commercial orchards of citrus and assess the use of RDI in different citrus cultivars. Two RDI strategies (RDI-1, irrigated at 50% of crop evapotranspiration (ETc) during summer and; RDI-2, irrigated at 35% ETc during the same period to RDI-1) will be compared with a control treatment irrigated at full requirements. As the level of water stress reached by trees is the important factor when RDI strategies are applied, the study of accurate water stress indicators for citrus is also needed. Thus, during the period of water restrictions the use of sap flow and canopy temperature measurements, obtained by thermal imaging or by means of fixed infrared thermometer sensors, will be assessed and compared to classical methods like stem water potential and stomatal conductance. / Ballester Lurbe, C. (2013). Regulated deficit irrigation in citrus: agronomic response and water stress indicators [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/28582 / Premios Extraordinarios de tesis doctorales

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