Abstract The expansion of residential areas has increased the demand for exotic and increasingly compact landscape plants. In this context, this work aimed to evaluate the effects of paclobutrazol (PBZ) and the timing of ethylene application on growth reduction and flowering anticipation in ornamental pineapples grown in pots. The randomized block design was used with factorial arrangement (2 x 5) and 4 replications and 4 plants per plot. The primary treatments are the presence and absence of PBZ. The secondary treatments were five times of floral induction with ethylene: 90; 120; 150; 180; 210 days after transplanting (DAT) the seedlings into the pots. It was evaluated the variables: height ratio between the heights of the pot and the plant; rosette diameter; leaves length ‘D’ and flowering index. At 255 DAT, although the plants did not respond to floral induction with ethylene, only those treated with PBZ were more compact and had different characteristics such as smaller size and a ratio below 1/3 of the height of the vase in relation to the plant that to favor its commercialization, in pot.

Resumo A diminuição das áreas residenciais tem aumentado a demanda por plantas paisagísticas exóticas e cada vez mais compactas. Neste contexto, o objetivo deste trabalho foi avaliar os efeitos do paclobutrazol (PBZ) e das épocas de aplicação de etileno na redução do crescimento e na antecipação da floração em abacaxizeiro ornamental cultivado em vaso. O delineamento experimental utilizado foi o de blocos ao acaso, em arranjo fatorial (2 x 5), com 4 repetições e 4 plantas por parcela. Os tratamentos primários foram a presença e a ausência de PBZ. Os tratamentos secundários foram cinco épocas de indução floral com etileno: 90; 120; 150; 180; 210 dias após o transplantio (DAT) das mudas, para os vasos. Foram avaliadas as variáveis: altura da planta; relação entre as alturas do vaso e da planta; diâmetro da roseta; comprimento da folha ‘D’ e índice de florescimento. Aos 255 DAT, apesar das plantas não responderem à indução floral com o etileno, apenas aquelas tratadas com PBZ apresentaram-se mais compactas e com características diferenciadas como menor porte e relação abaixo de 1/3 da altura do vaso em relação a da planta que favorecer sua comercialização, em vaso.

ABSTRACT The objective of this work was to evaluate the effects of irrigation depth on the commercial production of ornamental pineapple in pots. The experiment was carried out in a greenhouse located in Fortaleza, in the state of Ceará, Brazil. The experimental design was completely randomised, with five treatments and four replications. The treatments were irrigation depths estimated at 50, 75, 100, 125, and 150% of the evapotranspiration of a crop of edible pineapple. The plants were grown in one litre pots, with supplementary irrigation every two days. The variables evaluated were: number of leaves; length and width of the 'D’ leaf; diameter of the rosette; plant height; rate of flowering; length and diameter of the peduncle, syncarp and crown; crown to syncarp ratio; commercial productivity and water-use efficiency. An increase in irrigation depth produced a linear increase in the number of leaves, width of the 'D' leaf and rosette diameter, but had no effect on the other variables. Water-use efficiency decreased linearly with the increases in irrigation depth. Despite influencing leaf growth, each irrigation depth results in plants suitable for commercialisation in pots. The smallest irrigation depth gives the greatest economy and water-use efficiency.

RESUMO Informações sobre manejo da irrigação são imprescindíveis no sistema de produção destinado ao cultivo comercial de abacaxizeiro ornamental em vaso. Por isso, este trabalho avaliou os efeitos de intervalos de irrigação sobre o crescimento e produção da cultura em vaso. O experimento foi realizado entre 16/7/2015 e 21/5/2016, em telado antiafídeo, em Fortaleza, Ceará, Brasil. O delineamento experimental foi o inteiramente casualizado, com cinco tratamentos, quatro repetições e quatro plantas por parcela. Os tratamentos consistiram nos intervalos de irrigação de: 2; 4; 6; 8; e 10 dias. As plantas foram cultivadas em vasos de um litro, adubadas com fertilizante de liberação lenta e submetidas a irrigação suplementar por gotejamento. Foram analisadas no final do ciclo (402 dias) as variáveis: número de folhas; comprimento e largura da folha ‘D’; diâmetro da roseta; altura da planta; taxa de floração; comprimento e diâmetro do pedúnculo, sincarpo e coroa; relação coroa/sincarpo; e percentagem de plantas comerciais. Os intervalos de irrigação influenciaram o número de folhas, comprimento da folha ‘D’, diâmetro da roseta, altura da planta, taxa de floração e percentagem de plantas comercias. A irrigação realizada a cada dois dias resultou em economia de água, crescimento foliar e taxa de floração elevados e na maior percentagem de plantas comerciais. Irrigações com intervalos entre quatro e 10 dias aumentaram o desperdício de água e reduziram o crescimento foliar, taxa de floração e percentagem de plantas comerciais. O menor intervalo de irrigação é, portanto, o mais recomendado para a modalidade de cultivo em vaso.

ABSTRACT Information on irrigation management is essential in a production system for the commercial cultivation of ornamental pineapple in pots. As such, this work evaluated the effects of irrigation interval on the growth and production of the crop in pots. The experiment was carried out from 16/07/2015 to 21/05/2016 in a greenhouse located in Fortaleza, in the state of Ceará, Brazil. The experimental design was completely randomised, with five treatments, four replications and four plants per plot. The treatments consisted of irrigation intervals of 2, 4, 6, 8 and 10 days. The plants were grown in one-litre pots, fertilised with slow release fertiliser and subjected to supplementary drip irrigation. The following variables were analysed at the end of the cycle (402 days): number of leaves; length and width of the 'D' leaf; diameter of the rosette; plant height; rate of flowering; length and diameter of the peduncle, syncarp and crown; crown to syncarp ratio; and percentage of commercial plants. The irrigation interval influenced the number of leaves, length of the 'D' leaf, diameter of the rosette, plant height, rate of flowering and percentage of commercial plants. Irrigating every two days resulted in water savings, increased leaf growth and a high rate of flowering, and the greatest percentage of commercial plants. Irrigating at intervals of between four and 10 days, increased water wastage, and reduced leaf growth, the rate of flowering and the percentage of commercial plants. The shortest irrigation interval is therefore the most recommended for cultivation in pots.

ABSTRACT Electromagnetic and ultrasonic flowmeters are high precision devices that can measure the water flow in pressurized irrigation networks. In these networks, the inadequate installation distance of flow control valves generates upstream disturbances which will increase measurement errors and reduce the accuracy of the equipment. Therefore, estimating these errors is important to establishing the correct installation distance of the hydraulic accessories and to ensuring the metrological reliability of the flowmeters. This work proposes a numerical study using Computational Fluid Dynamics to evaluate water flow behavior in pipes and estimate measurement errors caused by gate and butterfly valves in installation configurations found at pressurized irrigation networks. The numerical simulations were made for gate (15, 50 and 75 % closed) and butterfly (open and 30º closed) valves installed three and six diameters (3D and 6D) from the flowmeters. The numerical study with three-dimensional simulation allows for evaluating the flow behavior and estimating measurement errors correctly. According to the study, the installation configurations of the gate and butterfly valves change the flow velocity profile at different positions in the pipe, generating both positive and negative measurement errors at both flowmeters. Among the tested configurations, only the butterfly valve installed 3D and 6D from the electromagnetic flowmeter ensured the measurement accuracy required by ISO 4064.

ABSTRACT Venturi-type chemigation injectors are widely used due to their advantages: they do not require electric power and are cheap to operate. However, they also generate considerable energy losses which affect the pressure in the system. The correct characterization of these systems requires pressures to be correctly set at the inlet, injector and outlet points in relation to main and injected solution flows. These analytical relationships, as described in the International Organization for Standardization’s standard ISO 15873:2002, can be obtained theoretically, although it is recommended that the manufacturer should determine the real behavior of the injector by operational tests. These relationships should also be provided graphically in the form of nomograms in order to facilitate the association of the variables involved and the subsequent selection of a specific model or class and type of assembly. In order to make the right choice, it is also necessary to have precise information on the irrigation sub-units that it feeds and the grower’s fertilization program.

RESUMEN El inyector para quimigación tipo Venturi tiene ventajas que hacen que sea un dispositivo bastante utilizado; no requiere energía eléctrica y es económico. Por el contrario, genera pérdidas de energía elevadas, afectando a las presiones en la instalación. Para una correcta caracterización de estos equipos deben relacionarse las presiones en los puntos de entrada, salida e inyección con los caudales principales e inyectados. Estas relaciones analíticas, que las introduce la norma de la Organización Internacional de Normalización (ISO 15873:2002), se pueden obtener de forma teórica; aunque es más recomendable que el fabricante establezca mediante ensayos de funcionamiento, el comportamiento real del inyector. Es oportuno que estas relaciones se proporcionen gráficamente, en la forma de nomogramas, para facilitar la asociación de las variables implicadas y la posterior selección de un modelo o clase concretos bajo una tipología de montaje. Así, para que esta selección sea adecuada es necesario también el conocimiento preciso de las subunidades de riego que alimenta y el programa de fertilización de la explotación.

Resumo Para manter a qualidade de medição do consumo de água, é necessário conhecer a metrologia de hidrômetros unijato ao longo do tempo. Conhecer a metrologia desses instrumentos com o tempo permite estabelecer um período de operação metrológica para diferentes vazões. Isso ajudará as empresas de água a otimizar a gestão e a reduzir as perdas econômicas devido ao consumo do volume de água não contabilizado. Neste estudo, a influência do fator tempo sobre o erro de medição de hidrômetros unijato foi analisada com o objetivo de estimar sua deterioração e, com isso, o período de operação metrológica. Conforme as normas 8316 e 4064 da Organização Internacional de Normalização (ISO), foram avaliados em seis abastecimentos 808 hidrômetros de classe metrológica B, com uma faixa de idade de 3,7 a 16,4 anos de uso. O erro de medição foi calculado pela comparação entre o volume de um depósito calibrado e o volume medido pelos hidrômetros, nas vazões de 30, 120, 750 e 1.500 L h-1. O período de operação metrológica dos medidores foi estimado para cada vazão, por meio da relação entre erro de medição e tempo de uso (regressão linear simples). De acordo com os resultados, a maioria dos hidrômetros apresenta erros crescentes de submedição com o tempo, sendo mais pronunciados nas vazões reduzidas e nas condições de funcionamento menos favoráveis. O período de operação metrológica para as vazões de 30, 120, 750 e 1.500 L h-1 é estimado em aproximadamente 3, 8, 14 y 13 anos. Este período de operação, combinado com os padrões de consumo dos usuários, estabelecerá o melhor momento para substituir os hidrômetros.

Abstract To maintain quality measurement of water consumption, it is necessary to know the metrology of single-jet water meters over time. Knowing the accuracy of these instruments over time allows establishing a metrological operation period for different flow rates. This will aid water companies to optimize management and reduce economic losses due to unaccounted water consumption. This study analyzed the influence of time on the measurement error of single-jet water meters to evaluate the deterioration of the equipment and, with that, launch the metrological operation period. According to standards 8316 and 4064 of the International Organization for Standardization (ISO), 808 meters of metrological Class B were evaluated in six water supplies, with age ranges of 3.7 to 16.4 years of use. The measurement error was estimated by comparing the volume measured in a calibrated tank with the volume registered by the meters at flow rates of 30, 120, 750 and 1,500 L h-1. The metrological operation period of the meters was obtained for each flow rate by the relation between error of measurement and time of use (simple linear regression). According to the results, the majority of the equipment presents increasing under-registration errors over time, more pronounced at low flow rates and with less favorable operating conditions. The metrological operation period for flow rates of 30, 120, 750 and 1,500 L h-1 is estimated at approximately 3, 8, 14 and 13 years. This operation period combined with consumption patterns of users will establish the best time to replace the meters.

RESUMO Informações locais sobre manejo hídrico em olerícolas podem oferecer maior precisão ao fornecimento de água pela irrigação, concorrendo para elevar a produtividade e reduzir os custos. Neste trabalho, foram avaliados os efeitos de distintos níveis de irrigação sobre a produção do melão-amarelo e sobre o fator de resposta da cultura frente à irrigação deficitária (Ky). O experimento foi conduzido em Fortaleza, Ceará, utilizando o delineamento em blocos casualizados, com seis tratamentos, quatro repetições e parcelas de seis plantas. Os tratamentos foram diferenciados nas fases fenológicas intermediária (III) e final (IV), com lâminas de água correspondentes a 25%, 50%, 75%, 100%, 125% e 150% da evapotranspiração da cultura (ETc). O Ky foi estimado pela metodologia do Boletim 33 da FAO, no intervalo de 25% a 100% da ETc. Foram analisadas as variáveis número de frutos por planta, diâmetros polar e equatorial, massa fresca do fruto, produtividade comercial, espessuras da casca e da polpa e sólidos solúveis. Os tratamentos influenciaram significativamente sobre o número de frutos por planta, o diâmetro equatorial, a massa fresca do fruto, a produtividade comercial e os sólidos solúveis. As irrigações com 100,3% da ETc na fase produtiva do meloeiro maximizaram a produtividade comercial, estimada em 32,2 Mg ha-1 e proporcionaram 1,46 fruto por planta com diâmetro equatorial de 16,3 cm, massa fresca de 2,3 kg e sólidos solúveis de 12 ºBrix. A cultura mostrou-se tolerante à redução do suprimento de água na fase produtiva (Ky < 1) com a adoção, da irrigação diária com déficit hídrico controlado.

ABSTRACT Local knowledge about irrigation management in yellow melon can promote higher precision to water supply for irrigation purposes, increasing productivity and reducing production costs. The aim of this study was to evaluate the effects of different irrigation depths for yellow melon production and on yield response factor to water (Ky) in the productive phase. The experiment was carried out in Fortaleza, state of Ceará, Brazil, in complete randomized blocks with six treatments, four replicates and six plants per plot. Treatments were applied from intermediate (III) to final (IV) physiological state with water depths equivalents to 25%, 50%, 75%, 100%, 125% and 150% of the crop evapotranspiration (ETc). Ky was calculated according to FAO-33 report methodology in the range from 25% to 100% ETc. The variables analyzed were number of fruits per plant, polar and equatorial diameters, fruit fresh weight, commercial yield, skin and pulp thickness, and soluble solids. Treatments influenced the number of fruits per plant, equatorial diameter, fruit fresh weight, commercial yield, and soluble solids. The best results were reached with commercial yield equal to 32.2 Mg ha-1, 1.46 fruits per plant, equatorial diameter equal to 16.3 cm, fruit fresh weight equal to 2.3 kg and soluble solids equal to 12 ºBrix with 100.3% ETc in the productive phase. The crop was tolerant to water supply reduction on the productive phase (Ky < 1) through daily irrigation with controlled water deficit.

RESUMOPara aperfeiçoar o manejo fitossanitário de pragas na cultura do melão (Cucumis melo L.), objetivou-se avaliar os efeitos de formas de aplicação e doses de inseticidas sobre a eficiência de controle químico do pulgão A. gossypii. O experimento foi realizado em 2010, na cidade de Fortaleza, Ceará, com melão amarelo cultivado em condições de campo. O delineamento experimental foi em blocos ao acaso, arranjo fatorial 2 x 4, com quatro repetições e parcelas de seis plantas. Os tratamentos foram duas formas de aplicação (pulverização costal manual e insetigação por gotejamento) e quatro doses de inseticida (0; 50; 100; 200% da dose recomendada pelo fabricante). Os inseticidas acefato e tiametoxam, testados separadamente, foram aplicados em manejo de rotação de grupos químicos. A eficiência de controle foi avaliada sete dias após o uso de cada inseticida. O acefato não apresentou diferença significativa entre as formas de aplicação, atingindo eficiências de controle de 88,95 e 84,09% com 100 e 200% da dose recomendada, respectivamente. O tiametoxam não diferiu significativamente quanto às formas de aplicação e doses testadas, apresentando eficiência de 100% em todos os tratamentos. Atualmente, no Brasil, a utilização de acefato no melão está limitada à aplicação mecanizada devido ao risco de contaminação. Diante dessa limitação, o controle do pulgão em meloeiro amarelo pode ser realizado via insetigação por gotejo ou pulverização costal manual, devendo-se empregar, preferencialmente, 100% da dose recomendada de tiametoxam.

ABSTRACTIn order to perfect the phytosanitary management of pests in the melon crop (Cucumis melo L.), the aim here was to evaluate the effects of different methods of application and dosages of insecticides on the effectiveness of chemical control of the aphid A. gossypii. The experiment was carried out in 2010, in Fortaleza, in the state of Ceará, Brazil, with yellow melon grown under field conditions. The experimental design was of randomised blocks in a 2 x 4 factorial arrangement, with four replications and lots of six plants. Treatments consisted of two methods of application (manual backpack spray and drip insectigation) and four dosages of insecticide (0, 50, 100 and 200% of the dosage recommended by the manufacturer). The insecticides acephate and thiamethoxam, tested separately, were applied in a rotating management of chemical groups. Efficiency of the control was evaluated seven days after the use of each insecticide. The acephate showed no significant difference between the forms of application, reaching control efficiencies of 88.95 and 84.09% with 100 and 200% of the recommended dose respectively. The thiamethoxam did not differ significantly for the application methods and dosages under test, giving 100% efficiency in all treatments. Currently in Brazil the use of acephate in the melon is limited to mechanised application due to the risk of contamination. Because of this limitation, the control of aphids in yellow melon can be carried out via drip insectigation or backsack spray, with preferably 100% of the recommended dose of thiamethoxam.

The performance and installation alternatives of four Venturi injector prototypes were studied at Universitat Politècnica de València, Valencia, Spain (39°29' N; 0°23' W; 20 m). This device performance was studied under several parameters such as head loss, relation of flows and injection efficiency. The installation configurations analyzed were: without the injection of nutrients solution and with the injection either having negative or positive pressure at the Venturi throat. The inlet pressures were established between 10 and 40 m.w.c. The experimental data has been processed using multiple stepwise regression techniques and analysis of variance (ANOVA). Moreover, geometry integration versus diameters, flows and pressures is used to obtain some equations for predicting the head loss and injected flow. The results of the present study showed that the relation between flows and injection efficiency were better when the diameter of inlet nutrient line increases and become worse when decreases the diameter of the Venturi throat. Accordingly, these dimensions become very important in the design prototype and installation configuration. Furthermore, after the analysis of laboratory experiments it can be concluded that head losses, at the same injected flow, were lower if the injection was carried out with positive pressures at the throat than in the case of negative pressures. Also in this case, the relationship between flow rates and injection efficiency leaded to a good performance of the proposed installation.

En la UniversitatPolitécnica de València, Valencia, Espana (39°29' N; 0°23' W; 20 m), ha sido estudiado el funcionamiento de cuatro prototipos de inyector Venturi y tres formas de instalación distintas. El funcionamiento se ha analizado bajo diversos parâmetros, como pérdidas de carga, relación de caudales y rendimiento. Las formas de instalación analizadas han sido: sin inyección y con inyección y presiones negativas o positivas en la garganta. Las presiones se establecieron entre 10 y 40 m.c.a. A partir de los datos experimentales han sido procesados utilizando técnicas de regresión múltiple y análisis de la varianza. Con ellas, fue posible, a través de la integración de geometrías en función de los diâmetros, caudales y presiones, obtener expresiones para prever la pérdida de carga o el caudal inyectado. Se pone de manifiesto que la relación de caudales y el rendimiento son mayores cuanto mayor es el diámetro de la aspiración y empeoran al reducirse el diámetro de la garganta, siendo estas las dimensiones que más condicionan la inyección. También, puede afirmarse que la pérdida de carga, para un mismo caudal inyectado, es inferior si la operación se realiza con presiones positivas que con presiones negativas. La relación de caudales o el rendimiento también proporcionan valores más elevados bajo esta forma de instalación propuesta.