Research Interests:
Research Interests:
Summary Water scarcity due to global warming can increase the water demand for upland rice at critical stages of crop development. However, there is little research on cultivar responses to this scenario and technologies that enhance... more
Summary Water scarcity due to global warming can increase the water demand for upland rice at critical stages of crop development. However, there is little research on cultivar responses to this scenario and technologies that enhance water use efficiency (WUE). To determine the influence of water stress at and after flowering stages of drip-irrigated upland rice cultivars on physiology, yield, and WUE, a shelter experiment was conducted using a randomized block design with a split-plot arrangement of treatments. Three modern and one traditional cultivar were subjected to five irrigation managements: 100% of the field capacity considered the reference management (RM), 70 and 40% of the RM at the flowering stage, and 70 and 40% of the RM at the grain-filling stage. In general, the modern cultivars tended to maintain higher photosynthetic rate, stomatal conductance, transpiration, leaf water potential, and lower crop water stress index compared to the traditional cultivar under water s...
Research Interests:
For grasses and other crops in general, soil water potential has been widely studied to determine if there is a deficit or excess of water content in the soil. However, the plant water absorption process is not only modulated by soil... more
For grasses and other crops in general, soil water potential has been widely studied to determine if there is a deficit or excess of water content in the soil. However, the plant water absorption process is not only modulated by soil water potential but also by the combination of meteorological, soil depth, and crop canopy factors, which could be elucidated through water relations responses. The objective of this work was to compare the water relations of grass species established in different soil depths and subjected to water stress. Santo Agostinho (Stenotaphrum secundatum), Esmeralda (Zoysia japonica), Tanzania (Panicum maximum) and Tifton 85 (Cynodon spp.) were used in this trial. The four species of grasses were tested in four different soil rooting depths: 10, 20, 30 and 40 cm. The grasses were irrigated at soil moisture field capacity level, until the time of imposing the water stress period. Soil depth had a direct influence on leaf water potential and soil water potential....
Research Interests:
Irrigation is a useful tool to achieve a better productivity and quality foods, which contributes to a higher efficient use of agriculture land. Drip irrigation is characterized by higher application efficiency, providing an efficient... more
Irrigation is a useful tool to achieve a better productivity and quality foods, which contributes to a higher efficient use of agriculture land. Drip irrigation is characterized by higher application efficiency, providing an efficient control of the irrigation depth required. Moreover, it has advantages such as lower evaporation loss and higher crop yields when associated with fertigation. However, dripper clogging is pointed out by several authors as the main limiting factor for a rapid adoption of drip irrigation on a larger scale. Emitter clogging susceptibility depends basically on five parameters: water quality, filtration system, fertilizer quality, labyrinth architectural layout and maintenance procedures. The adoption of chemical treatments helps to control biological agents and precipitates, making it possible to minimize the risk of clogging. This paper aims to understand how drip clogging process occurs, providing scientific arguments and support on the development of a s...
Research Interests:
Leaf area estimation is a very important indicator in studies related to plant anatomy, morphology and physiology, and in many cases, it is a fundamental criterion to understand plant response to input conditions. Although there are leaf... more
Leaf area estimation is a very important indicator in studies related to plant anatomy, morphology and physiology, and in many cases, it is a fundamental criterion to understand plant response to input conditions. Although there are leaf area prediction models have been produced for some plant species, a leaf area estimation model has not yet been developed for the zucchini. The objective of this paper was to determine the leaf area based on destructive and non-destructive methods for zucchini. The accuracy of measurement methods was evaluated and compared to determinations of the leaf area by the scanning integration method (LICOR equipment LI 3100C), considered as standard procedure. Non-destructive methods consisted of digital photography and measurement of leaf dimensions (width and length) based on ImageJ software. The destructive methods used were a) leaf area integrator LI-3100C, b) determination of leaf mass and c) weighing of leaf discs punched from the leaves. According to...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
CONSUMO DE SOLUÇÕES FERTILIZANTES EM PLANTAS ADULTAS DE LIMA ÁCIDA ‘TAHITI’ SOBRE LIMÃO ‘CRAVO’ NAS CONDIÇÕES DE IRRIGAÇÃO LOCALIZADA Carmello Crisafulli Machado; Ithamar Prada Neto; Rubens Duarte CoelhoDepartamento de Engenharia Rural,... more
CONSUMO DE SOLUÇÕES FERTILIZANTES EM PLANTAS ADULTAS DE LIMA ÁCIDA ‘TAHITI’ SOBRE LIMÃO ‘CRAVO’ NAS CONDIÇÕES DE IRRIGAÇÃO LOCALIZADA Carmello Crisafulli Machado; Ithamar Prada Neto; Rubens Duarte CoelhoDepartamento de Engenharia Rural, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba, SP, ccmachad@esalq.usp.br 1 RESUMO O trabalho de pesquisa foi realizado em um pomar com dez anos de idade, teve como objetivo medir o consumo de diferentes soluções fertilizantes pelo sistema radicular de porta-enxerto limão ‘Cravo’ sobre lima ácida ‘Tahiti’, pela metodologia do lisímetro poroso. Na projeção da copa de cada uma das plantas foram instalados nove conjuntos lisímetricos, sendo três para cada tratamento a ser implantado, sendo estes: água pura (testemunha) Tratamento 1, solução fertilizante com N, P e K Tratamento 2 e solução fertilizante com N, P, K, Ca, Zn e B Tratamento 3. A inclusão dos elementos Ca, Zn, B, e S na solução de N, P e K (Tratam...
Research Interests:
Com o propósito de se avaliar a eficiência de diferentes dosagens de cloro na desobstrução por tratamento de choque de gotejadores, conduziu-se um experimento no Laboratório de Irrigação do Departamento de Engenharia Rural da Escola... more
Com o propósito de se avaliar a eficiência de diferentes dosagens de cloro na desobstrução por tratamento de choque de gotejadores, conduziu-se um experimento no Laboratório de Irrigação do Departamento de Engenharia Rural da Escola Superior de Agricultura "Luiz de Queiroz"- ESALQ/USP, no qual foram utilizados os seguintes tipos de gotejador Netafim: Streamline 100, Ram 17L, Dripline 2000, Tiran 17 e Typhoon 20, e avaliadas as dosagens de cloro de 150, 300, 450 e 600 mg L-1. A água utilizada no ensaio foi proveniente de fonte hídrica superficial, aproveitada para irrigação. Para os tratamentos de recuperação dos emissores, utilizou-se o hipoclorito de sódio comercial (12%) como fonte de cloro, aplicado continuamente por 60 min, e logo após, deixou-se o produto interagir por 12 h na mangueira, sem fluxo na rede. Para todos os emissores, exceto o Streamline, a aplicação de cloro resultou em aumento da vazão média. Para o modelo Dripline, o tratamento com cloro reduziu a unif...
Research Interests:
The modern techniques of water supply through irrigation can substantially reduce water waste, which contributes to attend the enlarging water demand. The objective of this work was to study the influence of subsurface drip irrigation and... more
The modern techniques of water supply through irrigation can substantially reduce water waste, which contributes to attend the enlarging water demand. The objective of this work was to study the influence of subsurface drip irrigation and mulching over melon yield and quality characteristics, in a sandy soil (Typic Hapludox). The experimental design was blocks at random, with four replications. Treatments were displayed in a 2 x 3 factorial (with and without mulching x surface and 0.20 and 0.40 depth subsurface drip irrigation). Mulching using double-sided silver/black film increased fruit average mass, plant production, yield, daily growth rate for plant height and crown diameter, fruit distal diameter, and pulp thickness. The subsurface drip irrigation at 0.20 m depth resulted in larger fruit average mass, plant production, and yield than surface and 0.40 m depth drip irrigation.
Research Interests:
Avaliou-se a suscetibilidade de cinco tipos de gotejadores ao processo de entupimento de origem biológica, testando-se os seguintes modelos da marca comercial Netafim: Streamline 100, Ram 17L, Dripline 2000, Tiran 17 e Typhoon 20; para... more
Avaliou-se a suscetibilidade de cinco tipos de gotejadores ao processo de entupimento de origem biológica, testando-se os seguintes modelos da marca comercial Netafim: Streamline 100, Ram 17L, Dripline 2000, Tiran 17 e Typhoon 20; para tanto, utilizou-se delineamento estatístico em blocos ao acaso em parcela subdividida, constituído de cinco tratamentos (modelo de gotejador) na parcela e tempo de funcionamento (9 níveis) na subparcela com quatro repetições. A água utilizada no ensaio provinha de fonte hídrica superficial, utilizada para irrigação, e dela foram isolados diversos gêneros de bactérias, multiplicadas em meio de cultura e utilizadas para manter um nível populacional de bactéria no reservatório da bancada de ensaio superior a 50.000 UFC mL-1, através de inoculações efetuadas quando o número de células decaía a esse patamar. Em intervalos de tempo de funcionamento do sistema de 240 h, a vazão de cada gotejador era medida totalizando um tempo de 2160 h de operação. Os resul...
Research Interests:
In this study is presented an economic optimization method to design telescope irrigation laterals (multidiameter) with regular spaced outlets. The proposed analytical hydraulic solution was validated by means of a pipeline composed of... more
In this study is presented an economic optimization method to design telescope irrigation laterals (multidiameter) with regular spaced outlets. The proposed analytical hydraulic solution was validated by means of a pipeline composed of three different diameters. The minimum acquisition cost of the telescope pipeline was determined by an ideal arrangement of lengths and respective diameters for each one of the three segments. The mathematical optimization method based on the Lagrange multipliers provides a strategy for finding the maximum or minimum of a function subject to certain constraints. In this case, the objective function describes the acquisition cost of pipes, and the constraints are determined from hydraulic parameters as length of irrigation laterals and total head loss permitted. The developed analytical solution provides the ideal combination of each pipe segment length and respective diameter, resulting in a decreased of the acquisition cost.
Research Interests:
This study aimed to evaluate the spatial variability of leaf content of macro and micronutrients. The citrus plants orchard with 5 years of age, planted at regular intervals of 8 x 7 m, was managed under drip irrigation. Leaf samples were... more
This study aimed to evaluate the spatial variability of leaf content of macro and micronutrients. The citrus plants orchard with 5 years of age, planted at regular intervals of 8 x 7 m, was managed under drip irrigation. Leaf samples were collected from each plant to be analyzed in the laboratory. Data were analyzed using the software R, version 2.5.1 Copyright (C) 2007, along with geostatistics package GeoR. All contents of macro and micronutrients studied were adjusted to normal distribution and showed spatial dependence.The best-fit models, based on the likelihood, for the macro and micronutrients were the spherical and matern. It is suggest for the macronutrients nitrogen, phosphorus, potassium, calcium, magnesium and sulfur the minimum distances between samples of 37; 58; 29; 63; 46 and 15 m respectively, while for the micronutrients boron, copper, iron, manganese and zinc, the distances suggests are 29; 9; 113; 35 and 14 m, respectively.
Research Interests:
Research Interests:
Research Interests:
Entupimento de gotejadores Entupimento de gotejadores Entupimento de gotejadores Entupimento de gotejadores Entupimento de gotejadores e seu efeito na pressão da rede e seu efeito na pressão da rede e seu efeito na pressão da rede e seu efeito na pressão da rede e seu efeito na pressão da rede hi...more
Abstract: Abstract: Abstract: Abstract: The present study attempts to evaluate the pressure increase in the hydraulic network of a micro-irrigation system when partial or total clogging of emitters occurs. The evaluated area was of 280... more
Abstract: Abstract: Abstract: Abstract: The present study attempts to evaluate the pressure increase in the hydraulic network of a micro-irrigation system when partial or total clogging of emitters occurs. The evaluated area was of 280 ha, with citrus irrigation based on subsurface auto-compensating drippers. The methodology utilized a mathematical model based on Bernoulli's equation, simulating the effects of different clogging rates on the network pressure. To evaluate the pressure variation in the system, the obstructions in the range from 0 to 100% were simulated. For the condition of 50% clogging, 80% of the total pipeline length presented hydraulic pressure more than the nominal pressure foreseen in the project. The mathematical model permitted the simulation of: (a) the variation of the motor-speed of the pump (diesel energy), as a possible solution for controlling the excess pressure problem due to clogging (b) the pressure increase in the network with rotation in exces...
Research Interests:
Research Interests:
Research Interests:
O presente trabalho teve como objetivo básico o desenvolvimento de uma metodologia para a quantificação do acúmulo de água na superfície do solo, em função da intensidade de precipitação dos emissores de um infiltrômetro de aspersores... more
O presente trabalho teve como objetivo básico o desenvolvimento de uma metodologia para a quantificação do acúmulo de água na superfície do solo, em função da intensidade de precipitação dos emissores de um infiltrômetro de aspersores (IAS). Em condições de intensidade de precipitação abaixo da velocidade básica do solo (VIB) o microrrelevo superficial comportou-se de maneira estável, apresentando uma superfície espelhada crescente (acúmulo de água) sobre o solo, ao longo dos primeiros 120 min de ensaio e, em condições de intensidade de precipitação acima da velocidade básica (VIB) observou-se que a superfície espelhada estabilizava-se em menos de 30 min, apresentando, posteriormente, a formação de canais preferenciais de escoamento de água sobre o solo (erosão laminar).
Research Interests:
AGRIS record. Record number, XS2001250211. Titles, Variabilidade espacial de variáveis físico-hídricas do solo em um pomar de lima ácida Tahiti, irrigado por microaspersão. Personal Authors, Coelho Filho, Maurício A.(USP ...
AGRIS record. Record number, XS2005130318. Titles, Influência do manejo da irrigação no meloeiro rendilhado cultivado em ambiente protegido. Personal Authors, Silva, Tonny JA(USP Escola Superior de Agricultura Luiz de ...
Research Interests:
Research Interests:
Research Interests:
Na irrigação localizada com gotejadores posicionados de modo subsuperficial há o risco potencial de partículas de solo serem succionadas através do orifício de saída de água, em virtude da ocorrência de vácuo podendo resultar no... more
Na irrigação localizada com gotejadores posicionados de modo subsuperficial há o risco potencial de partículas de solo serem succionadas através do orifício de saída de água, em virtude da ocorrência de vácuo podendo resultar no entupimento dos mesmos. Objetivou-se, com este trabalho, avaliar o efeito da aplicação de vácuo no desempenho de diferentes modelos de gotejadores sob duas condições de textura de solo e posicionados de modo subsuperficial. Os tratamentos consistiram da aplicação dos níveis de sucção de -10, -15, -20 e -40 kPa, em solos de textura arenosa e argilosa, em 23 modelos de gotejadores usados com mais de 1 ano de funcionamento. O desempenho dos emissores no gotejamento subsuperficial foi influenciado pela textura do solo. De modo geral, em 80% dos emissores o vácuo de -40 kPa proporcionou obstrução nos emissores e redução da vazão, em ambas as texturas de solo. A maior redução de uniformidade de aplicação de água ocorreu com o modelo Irrimon Irridrip Plus 2,5 L h-1...
Soil water availability is the main cause of reduced productivity, and the early development period most sensitive to water deficit. This study aimed to evaluate the drought resistance of the varieties of sugar-cane RB867515 and SP81-3250... more
Soil water availability is the main cause of reduced productivity, and the early development period most sensitive to water deficit. This study aimed to evaluate the drought resistance of the varieties of sugar-cane RB867515 and SP81-3250 during the early development using different levels of water deficit on four soil depths. The experiment was conducted at the Department of Biosystems at Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP) in a greenhouse in soil classified as Oxisol, sandy loam texture (Series "Sertãozinho"). Once exhausted the level of available water in the soil, the dry strength of the studied strains are relatively low. Water balance with values less than -13 mm cause a significant decrease in the final population of plants, regardless of the variety, and values below -35 mm, leads to the death of all plants.
Research Interests:
The aim of this study was to evaluate the water productivity into biomass and into sugar for 23 sugarcane varieties (second ratoon crop) under two levels of drip irrigation. Two experiments were conducted in a greenhouse. Experiment 1... more
The aim of this study was to evaluate the water productivity into biomass and into sugar for 23 sugarcane varieties (second ratoon crop) under two levels of drip irrigation. Two experiments were conducted in a greenhouse. Experiment 1 comprised nine sugarcane varieties grown in a clay soil and Experiment 2 was composed of 14 varieties in a sandy-loam soil. Moreover, two irrigation treatments were adopted: T100 - full irrigation with 100% crop evapotranspiration replacement, maintaining soil moisture near field capacity for each variety; and T70 - irrigation with 70% T100 water depth. Water productivity was evaluated in terms of stem fresh biomass (WPFB) and sugar (WPGSY). The results showed that WPFB ranged from 11.45 to 18.45 kg m-3. The highest values were observed for varieties CTC14, CTC6, RB867515, and SP81-3250 (in T100) and for the varieties CTC6 and CTC14 (in T70). The WPGSY values ranged from 1.68 to 2.22 kg m-3, with emphasis placed on CTC6, RB9675-15, SP81-3250, and RB925...
Research Interests:
Leifsonia xyli subsp. xyli (Lxx) is a pathogenic bacterium that causes Ratoon Stunting Disease (RSD) in the sugarcane crop. Disease symptoms caused by Lxx have been associated with hormonal imbalance, which may be intensified when plants... more
Leifsonia xyli subsp. xyli (Lxx) is a pathogenic bacterium that causes Ratoon Stunting Disease (RSD) in the sugarcane crop. Disease symptoms caused by Lxx have been associated with hormonal imbalance, which may be intensified when plants are under water deficit conditions. However, up to date there are no studies showing that Lxx colonization decreases water status in sugarcane. The objective of this study was to evaluate the effect of water status and physiological traits of sugarcane colonized by Lxx under irrigation and water deficit conditions. We inoculated cuttings of the sugarcane genotype CB 49260 with Lxx using four treatments: i) healthy plants fully irrigated, ii) healthy plants under water deficit, iii) plants inoculated with Lxx fully irrigated, and iv) plants inoculated with Lxx under water deficit. Lxx inoculation in sugarcane did not affect relative water content (RWC) in the leaves, independently of the water conditions tested. For gas exchange and fluorescence traits, we did not identify differences between plants inoculated with Lxx and healthy plants. As expected, plants under water deficit conditions decreased RWC, CO2 assimilation, stomatal conductance, transpiration and fluorescence traits, and increased soluble amino acids and proline contents in the leaves. Lxx inoculation increased amino acids and proline contents in plants under water deficit conditions. Therefore, the results indicated that sugarcane colonized with Lxx did not change plant water status independently of the water conditions during the entire growing season.
Research Interests:
Research Interests:
Research Interests:
ASPERSÃO CONVENCIONAL: SIMULAÇÕES DE DIMENSIONAMENTO ECONÔMICO EM PLANILHA ELETRÔNICA Jarbas Honorio de MirandaBolsista do CNPq - ESALQ-USP - Departamento de Engenharia RuralFone: (019) 429-4217; Fax: (019) 433-0934CEP: 13418-900 -... more
ASPERSÃO CONVENCIONAL: SIMULAÇÕES DE DIMENSIONAMENTO ECONÔMICO EM PLANILHA ELETRÔNICA Jarbas Honorio de MirandaBolsista do CNPq - ESALQ-USP - Departamento de Engenharia RuralFone: (019) 429-4217; Fax: (019) 433-0934CEP: 13418-900 - Piracicaba-SPCarlos Amilton Silva SantosBolsista CAPES - ESALQ-USP - Departamento de Engenharia RuralFone: (019) 429-4217; Fax: (019) 433-0934CEP: 13418-900 - Piracicaba-SPRubens Duarte CoelhoESALQ-USP - Departamento de Engenharia RuralFone: (019) 429-4217; Fax: (019) 433-0934CEP: 13418-900 - Piracicaba-SP 1 RESUMO O sistema de irrigação por aspersão convencional constitui-se tradicionalmente de um conjunto de condutos forçados formando a linha principal e as linhas laterais portáteis, que são deslocadas ao longo do campo, a fim de que toda a área seja irrigada.O dimensionamento de um sistema de aspersão convencional portátil baseado na análise econômica, permite a escolha dos diâmetros a serem utilizados em diferentes situações de trabalho, propor...
Research Interests: Mathematics and Physics
Research Interests:
A irrigação por gotejamento subsuperficial, que utiliza um sistema protetor do emissor para evitar entupimento do mesmo por raiz e partículas sólida do solo, pode ser viável em relação a um sistema convencional. Propôs-se, com este... more
A irrigação por gotejamento subsuperficial, que utiliza um sistema protetor do emissor para evitar entupimento do mesmo por raiz e partículas sólida do solo, pode ser viável em relação a um sistema convencional. Propôs-se, com este trabalho, avaliar o desempenho de um sistema para proteção de emissor e comparar os resultados com um sistema que utiliza emissor convencional para irrigação por gotejamento subsuperficial. O sistema com protetor foi construído com materiais de baixo custo: mangueira de polietileno, microtubo, conector e um gotejador para controlar a vazão e no sistema convencional utilizou-se um emissor comercial. Após 12 meses de avaliação o sistema com protetor demonstrou bom desempenho com vazão relativa média de 0,97 e 0,98 em vasos com e sem cultura, respectivamente, não apresentando problemas de entupimento e tendo menor custo. No sistema convencional constatou-se vazão relativa de 0,51 e 0,98 em vasos com e sem cultura, respectivamente, grau de entupimento por rai...
Research Interests:
Research Interests:
Although several studies have been conducted to evaluate the uniformity of water application under center pivot irrigation systems, there are few studies concerning the economic perspective of such coefficient. The aim of this study is to... more
Although several studies have been conducted to evaluate the uniformity of water application under center pivot irrigation systems, there are few studies concerning the economic perspective of such coefficient. The aim of this study is to present a methodology to accomplish an economic analysis as support for the decision-making to retrofit emitters in center pivot irrigation systems, and to attribute an economic meaning to the uniformity coefficient of water application taking into account the response function productivity to the amount of water applied and the sale price of the crops. In the hypothetic calculation example considering the variation of revenue of potato crop under center pivot irrigation system, it was verified that the area with uniformity coefficient of water application of 90% brought an income increase of BR$ 1,992.00, considering an area about 1,0 ha. Thus, it can be concluded that the methodology presented has met the objectives proposed in the study and made...
This paper reviews various irrigation technologies in both South Africa and Kenya that enable improvements in their socio-economic conditions. The two countries are located in semi-arid areas that experience extreme fluctuations in the... more
This paper reviews various irrigation technologies in both South Africa and Kenya that enable improvements in their socio-economic conditions. The two countries are located in semi-arid areas that experience extreme fluctuations in the availability of rain water for plant growth. Population growth exceeds the ability to produce food in numerous countries around the world and the two countries are not an exception. This experiment examined the constraints that farmers face and the role of government and nongovernmental organization in the uptake of modern technologies for irrigation. Detailed mechanisms and options to secure sustainable irrigation which are economically viable are considered. Despite the higher production of cereals and grains, fruits, and flowers also thrive in the two countries. Total irrigated area, crops grown and irrigation systems used in the two countries are discussed.
Research Interests: Geography and Irrigation
Research Interests:
Cropping intensification and technical, economic and environmental issues require efficient application of production factors to maintain the soil productive capacity and produce good quality fruits and vegetables. The production factors,... more
Cropping intensification and technical, economic and environmental issues require efficient application of production factors to maintain the soil productive capacity and produce good quality fruits and vegetables. The production factors, water and NPK nutrients, are the most frequent limiting factors to higher melon yields. The objective of the present study was to identify the influence of subsurface drip irrigation and mulching in a protected environment on the water and NPK nutrients productivity in melon cropped in two soil types: sandy loam and clay. The melon crop cultivated under environmental conditions with underground drip irrigation at 0.20m depth, with mulching on sandy loam soil increased water and N, P2O5 and K use efficiency.