José Antônio Frizzone

Produtividade do maracujazeiro amarelo sob diferentes níveis de irrigação e doses de potássio via fertirrigação

The objective of this work was to study the effect of four irrigation levels and five K doses applied through fertirrigation by drip irrigation system in the yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg.) yield. A complete randomized block design in plot subdivided with four replications was used. The treatments resulted from the combination of four irrigation levels [0.25V (926.76 L), 0.50V (1,528.20 L), 0.75V (2,117.28 L) and 1.00V (2,706.36 L), where V is the average volume of water applied in lysimeter with passion fruit plant] with five K doses (0.000, 0.225, 0.450, 0.675 and 0.900 kg plant-1 year -1 of K2O). The commercial yield was affected by irrigation levels, K doses and by the interaction irrigation levels vs. K doses. The majors values of passion fruit commercial yield were obtained with the application of 0.450 to 0.675 kg plant-1 year -1 of K2O, and water levels of 1,528.20 to 2,117.28 L plant-1 year -1, respectively.

Intercomparison testing and evaluation of sprinklers within the INITL

The International Network of Irrigation Testing Laboratories (INITL) undertook a sprinkler intercomparison testing exercise to generate data for an objective comparison of the performances of the different facilities and identify opportunities for further improvements.nThree impact sprinklers were tested in four laboratories in accordance with established standards. The plots of flow rate-pressure profiles were found to be consistent, and correlated to those obtained from previous studies. Although there were slight variations in the measured flow ratendata, the mean flow rates at each pressure level were the same for the three sprinklers, and the shapes of the radial distribution profiles were similar. The deviations of reconstituted flow rates (from the measured) of at least two tests in each facility were found to exceed the recommendednlimit. The sprinkler software developed by INITL was found to have a good correlation with a related commercial softwarenprogram.

Precipitação esperada, em diferentes níveis de probabilidade, na região de Dourados, MS

The aim of this work was to determine the dependable rainfall using different levels of probability in Dourados, Mato Grosso do Sul State, Brazil. This study was conducted for intervals of 10, 15 and 30 days, based on daily data of rainfall for 17 years. Series were adjusted to a mixed distribution and a non-parametric test Kolmogorov-Smirnov was used . The parameters of gama distribution were estimated by the method maximum likelihood. Data were adjusted to all periods. Based on the accumulated mixed distribution were generated values of rainfall for periods return of 2, 3, 4, 5, 10, 12 and 17 years. Results allow irrigation personal to adopt criterions values of rainfall for designing irrigation projects near Dourados-MS. The average rainfall should not be used because it may result in under estimation of the rainfall.

Performance of the Advisory System for Irrigators - S@I for water management in irrigated areas: benefits for farmers and to the district.

O Servico de Assessoramento ao Irrigante – SAI e um projeto que tem o objetivo de transmitir informacoes aos irrigantes sobre o manejo correto da irrigacao. Para realizar o manejo da irrigacao do SAI, foi desenvolvido em 2011 um software especifico para o sistema. O sistema de computacao criado e o Sistema Assessoramento ao Irrigante - S@I. Este sistema realiza os calculos necessarios para o envio da informacao diaria de quanto irrigar e possibilita uma rede social entre a gerencia do distrito e os irrigantes. Para validar as ferramentas do Sistema este trabalho objetivou avaliar a adocao do S@I e tambem apresentar indicadores economicos como a Produtividade de Agua (WP). Em relacao aos lotes, podemos concluir, de acordo com as entrevistas, que a utilizacao do Sistema S@I para o envio das informacoes aos irrigantes gerou visualmente beneficios aos produtores. Pelas analises realizadas, a WP variou de 0,68 R

Consumo de fertilizantes e produtividade da laranja em São Paulo ao longo das décadas de 1970, 1980 e 1990

.m-3 a 1,15 R

Minor losses in start connectors of microirrigation laterals

.m-3 para o DIBAU e de 1,19 R

Probabilidade de ocorrência da evapotranspiração de referência na região de Dourados, MS

.m-3 a 1, 38 R

Níveis de polímero superabsorvente, freqüências de irrigação e crescimento de mudas de café

.m-3 quando simulado pelo S@I. Em todas as situacoes a WP S@I foi mais alta do que a WP DIBAU demonstrando que havera maior valor de producao por metro cubico de agua se os produtores seguirem as recomendacoes do Sistema S@I. Desta forma, mesmo com a falta de dados para uma melhor conclusao em relacao aos lotes de cada irrigante, somente com a avaliacao da WP, o Sistema S@I se mostrou eficiente a nivel global, comprovado pelo beneficio que este Sistema pode fornecer ao Distrito na gestao da agua levando em consideracao o demandado pelas culturas implantadas.

Irrigation Advisory Service and Performance Indicators in Baixo Acaraú Irrigation District, Brazil

Brazil represents approximately 80% of the total frozen concentrate orange juice (FCOJ) traded in the international market. In addition, Brazil and the United States represent 50% of the total fresh orange produced around the world. Sao Paulo state is responsible by 98% of Brazilian FCOJ exports and by 80% of the national fresh orange production. The economic importance of Sao Paulos citrus industry has been stimulated researches in order to analyze all aspects related to citrus production system. Fertilizer is a very important input into citrus industry, especially in relation to production costs. Thus, this study has outlined the fertilizer consumed by Sao Paulos citrus industry in the 70s, 80s and 90s. It was developed models to estimate fertilizer consumption related to orange trees yields. Finally, it was developed a model to estimate an orange tree yield (boxes/tree) in relation to grove age from stochastic yields values estimated to each tree age. The models were well adjusted and meeting all econometrics requisites.

Intercomparison dripper testing within the INITL

Fittings called start connectors are usually employed to attach each lateral to its corresponding manifold in microirrigation systems. The protrusion of start connectors’ barbs into the manifold induces pressure losses due to contraction and subsequent enlargement of streamlines. In addition, when water flows from a manifold toward a lateral through a start connector, a sudden contraction followed by expansions of flow streamlines cause pressure loss whose intensity is influenced by connector’s geometry. Minor losses along manifolds or at laterals inlet due to start connectors may be significant and might be considered on subunits design or while undertaking hydraulic simulations. The objectives of this research were: (a) to develop equations based on dimensional analysis to estimate minor losses due to start connectors; (b) to compare the accuracy of the developed models against models that are currently used for estimating minor losses; (c) to undertake simulations to assess the relevance of minor losses due to start connectors in hydraulics of subunits. Minor losses due to start connectors were separated into two components. A model was developed and validated to estimate minor losses due to the protrusion of start connectors inserted along a manifold. Two models were developed and validated to estimate minor losses that occur when water flows from a manifold into a lateral line through a start connector. The required data to develop and validate the models were obtained experimentally in laboratory. Although minor losses due to start connectors represented a relative small percentage of total head losses, such effects may be significant while undertaking rigorous hydraulic simulations that require accurate estimation of pressure losses.