Effects of irrigation and nitrogen levels on qualitative and nutritional aspects of fig-trees (Ficus carica L.)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

WHEAT CULTIVARS: RESPONSE TO IRRIGATION and SOWING DATES

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of Meteorological Elements and Lettuce (lactuca Sativa, L.) Yield Related to Geographic Orientation of Polyethylene Greenhouses

O experimento foi realizado na área experimental do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas – Unesp/Botucatu, Estado de São Paulo, em duas estufas dispostas em diferentes orientações geográficas, Leste/Oeste e Norte/Sul. A alface (Lactuva sativa L.) cv. Elisa foi cultivada em ambas estufas, sendo semeada em 05/05/99, transplantada em 29/05/99 e colhida em 31/06/99. Utilizou-se tensiômetros para monitorar o potencial de água no solo para realizar o manejo do sistema de irrigação por gotejamento. Microevaporímetros eqüidistantes de 3 m e colocados em 3 alturas, 0.50, 1.00 e 1.50 m, termohigrógrafos e tanques Classe “A” foram instalados nas duas estufas. Através de análise geoestatística, não se observou dependência espacial nem variabilidade espacial da evaporação nas duas estufas. Entretanto, a altura dos evaporímetros apresentou diferenças significativas: a evaporação à altura de 1.50 foi menor que nas outras duas.As médias de temperatura, umidade relativa e déficit de pressão de vapor do arnão diferiram estatisticamente entre as estufas e o ambiente externo. Os valores médios de evaporação de água no tanque Classe A instalado fora das estufas diferiram estatisticamente quando comparados com os instalados no interior das estufas, porém, entre as orientações não se constatou diferença significativa. Pôde-se verificar que não houve diferença significativa das características agronômicas da alface em ambas orientações estudadas. No entanto, houve diferença significativa para essas características entre os canteiros no interior das mesmas, havendo variância espacial para os dados de matéria fresca apenas na estufa N/S.

Ratoon sugarcane yield integrated drip-irrigation and nitrogen fertilization

The aim of this study was to compare the use of water and nitrogen on ratoon sugarcane during irrigated and rain-fed conditions, and to assess the production potential of stalks and sugar with different rates of N-fertilizer on the subsurface drip-irrigated management. The experimental design was a randomized block with four replications for each experiment and treatments: (T1) irrigated, 0kg N ha-1; (T2) irrigated, 70kg N ha-1; (T3) irrigated, 140kg N ha-1; (T4) irrigated, 210kg N ha-1; (T5) not irrigated, 0kg N ha-1, and (T6) not irrigated, 140kg N ha-1. Biometric, technological, dry matter and yield variables were analyzed among the treatments. The irrigation system together with the application of N-fertilizer at 140kg ha-1 presented significant differences in dry matter accumulation of shoots, and for the production of stalks and sugar, respectively 94, 105 and 106%, higher when compared to the not irrigated, without N-fertilizer (T5). There was a positive and synergistic effect of irrigation with N-fertilizer on the productivity of stalks and sugar. Ratoon sugarcane irrigated with subsurface dripping had the highest yield (22Mg ha-1 of sugar) with the dosage of 140kg ha-1 N.

Irrigation and intercropping with macadamia increase initial arabica coffee yield and profitability

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Higher yield and economic benefits are achieved in the macadamia crop by irrigation and intercropping with coffee

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of irrigation and intracanal dressing on the healing process of dogs' teeth with apical periodontitis.

Dogs' teeth with apical periodontitis were treated endodontically, Dakin's solution being used in an experimental group as the irrigation solution, and camphorated paramonochlorophenol as an intracanal dressing. For a second group of teeth, the irrigation solution used was physiologic saline, dry cotton only being placed into the pulpal chamber to take the place of an intracanal dressing. In a second visit, overinstrumentation and a new application of the same kind of dressing were performed, the root canals being then filled with gutta-percha cones and zinc oxide-eugenol cement. Other specimens were treated, in one visit, where physiologic saline or Dakin's solution were the irrigation solutions. The animals were sacrificed 6 months after the obturation of the root canals. Histologic exams showed better results for the experimental group where Dakin's solution and camphorated paramonochlorophenol had been used, with signs of repair characterized by newly formed cementum and bone tissue, as well as a marked reduction in size of the periapical lesions. No differences were seen in the results with physiologic saline or Dakin's solution as irrigants.

Optimum design of microirrigation systems in sloping lands

When an area to be irrigated has a high slope gradient in the manifold line direction, an option is to use a tapered pipeline to economize on pipe costs and to keep pressure head variations within desired limits. The objective of this paper is to develop a linear optimization model to design a microirrigation system with tapered, downhill manifold lines, minimizing the equivalent annual cost of the hydraulic network and the annual pumping cost, and maximizing the emission uniformity previously established to the subunit. The input data are irrigation system layout, cost of all hydraulic network components, and electricity price. The output data are equivalent annual cost, pipeline diameter in each line of the system, pressure head in each node, and total operating pressure head. To illustrate its capability, the model is applied in a citrus orchard in Sao, Paulo State, Brazil, considering slopes of 3, 6, and 9%. The model proved to be efficient in the design of the irrigation system in terms of the emission uniformity desired.

PRACTICAL LAND GRADING BASED ON LEAST SQUARES.

Practical methods for land grading design of a plane surface for rectangular and irregularly shaped fields based on a least squares analysis are presented. The least squares procedure leads to a system of three linear equations with three unknowns for determination of the best-fit plane. The equations can be solved by determinants (Cramer's rule) using a procedure capable of solution by many programmable calculators. The detailed computational process for determining the equation of the plane and a simple method to find the centroid location of an irregular field are also given. An illustrative example and design instructions are included to demonstrate the application of the design procedure.

ADJUSTED F FACTOR FOR MULTIPLE-OUTLET PIPES.

An adjusted F factor to compute pressure head loss in pipes having multiple, equally spaced outlets is derived for any given distance from the first outlet to the beginning of the pipe. The proposed factor is dependent on the number of outlets and is expressed as a function of the J. E. Christiansen's F factor. It may be useful to irrigation engineers to estimate friction in sprinkle and trickle irrigation laterals and manifolds, as well as gated pipes.

Coeficientes de cultura para a melancieira irrigada por gotejamento no Vale do Gurgueia - PI

The aim of this work was to determine crop coefficients (Kc) of drip irrigated watermelon in the climatic and growing conditions of the Gurgueia Vale, State of Piaui, Brazil, located at 8 ° 26' S, 43 ° 47' W and altitude of 251 m. The reference evapotranspiration (ET0) was determined by the sum of hourly values of ET0 obtained by the Penman-Monteith method parameterized by FAO with climatic data obtained from an automatic weather station. The daily crop evapotranspiration (ETc) was measured by three weighing lysimeters of load cells. Aiming high fruit yield in this region, we recommend that the following local values of Kc and Kcb be used for planning and management of irrigation, respectively: initial stage (crop establishment) - 0.34 and 0.24; intermediate stage (growth and fruit maturation) - 1.16 and 1.10; end stage (harvest) - 0.93 and 0.86. These Kc values of initial and intermediate phases are statistically higher than the values of Kc and Kcb already adjusted according to the methodology presented in the FAO Irrigation and Drainage Paper 56. The values of Kc and Kcb at the end phase are not statistically different from the FAO values.

Avaliação da uniformidade em microaspersor autocompensante Naandan 2002 utilizando água com alto teor de ferro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evapotranspiração e coeficientes de cultura da melancieira irrigada por gotejamento em Alvorada do Gurguéia-PI

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

COMPORTAMENTO DO NONI À SALINIDADE DA ÁGUA DE IRRIGAÇÃO EM SOLO COM BIOFERTILIZANTE BOVINO1.

O excesso de sais no solo e em águas utilizadas para irrigação podem provocar perdas significativas de crescimento e de produção em plantas cultivadas. Dentre algumas alternativas para redução dos efeitos negativos dos sais às plantas em áreas cultivadas, a utilização do biofertilizante fermentado vem sendo explorada no cultivo de hortaliças e frutíferas irrigadas com água salina. Nesse sentido, o trabalho teve como objetivo avaliar o comportamento do noni à salinidade da água de irrigação em substrato sem e com biofertilizante bovino. Os tratamentos foram distribuídos em blocos ao acaso, com quatro repetições, utilizando o arranjo fatorial 5 x 2, correspondente a cinco níveis de condutividade elétrica da água de irrigação (0,5; 1,5; 3,0; 4,5; 6,0 dS m-1), em substratos com e sem biofertilizante bovino. Foram avaliados: altura de plantas, diâmetro do caule, número de folhas, área foliar, matéria seca da parte aérea e consumo hídrico. Todas as variáveis avaliadas foram influenciadas negativamente pelo incremento de sais na água de irrigação, mas sempre com menor intensidade nos tratamentos com biofertilizante bovino. O biofertilizante não elimina, mas atenua os efeitos negativos dos sais às plantas de noni.