Objetivou-se avaliar o efeito da aplicação de bactérias promotoras de crescimento na produção de mudas de bananeira sob irrigação salina. O experimento foi conduzido na Embrapa Agroindústria Tropical, localizada no município de Fortaleza, Ceará. Os tratamentos foram dispostos em blocos ao acaso (DBC) em esquema fatorial 3 x 4, referentes aos três tratamentos utilizados (controle, bactéria e adubo) e aos quatro níveis de salinidade da água de irrigação (0,5; 1,5; 3,0 e 4,5 dS m -1 ) com 4 repetições. Após 60 dias de experimento foram mensuradas as variáveis comprimento radicular (CR), altura da planta (AP), diâmetro do pseudocaule (DP), número de folhas (NF), área foliar (AF), massa fresca e seca das folhas (MFPA e MSPA, respectivamente) e teor de água nas folhas (TAF). As bactérias não apresentaram influência nas respostas das mudas de bananeira ao estresse salino.

Monitoring the quality of irrigation water can help in the maintenance of filters and irrigation systems, avoiding clogs and uniformity problems. The objective of this work was, thus, to evaluate the performance of sensor modules for monitoring irrigation water quality variables. For that, three sensors were evaluated, and their performance was rated from the adjustment of calibration equations, obtained through linear regression analysis (yi = b0 + b1xi + εi), using the ordinary least squares method (OLS) to estimate its parameters (β0 and β1). The first sensor evaluated was the Ph4502c for pH measurement. Direct methodology was used, using standard pH solutions (1.79; 4.5; 6.88; 12.13; and 13.99) and an electrode type BNC probe. The second evaluated sensor was turbidity model TSW30. To evaluate the total dissolved solids (TDS) sensor, the direct method was applied, using solutions with electrical conductivity of 0.50, 1.0, and 2.0 dS m-1. To investigate the assumptions of independence, homoscedasticity, and normality of the residuals of the linear regression models, the Durbin-Watson, Breusch-Pagan, and Kolmogorov-Smirnov tests were respectively used. In the evaluation of the statistical performance, the indicators of the root-mean-square error, coefficient of determination, correlation coefficient, confidence index, and index of agreement were adopted. The ordinary least squares method did not produce the best unbiased linear estimators for the calibration equations of the pH, turbidity, and TDS sensors, due to the violation of the regression assumptions. The adjustments showed good accuracy for water quality assessment, according to high performance statistics and models classified as ‘Excellent’.

The objective of this study was to evaluate the effect of inoculation of a plant growth promoter bacteria on the growth of micropropagated banana seedlings cultivar Williams under irrigation with water at different saline levels. The experiment was carried out in a greenhouse at Embrapa Agroindústria Tropical, Fortaleza, State of Ceará. The experimental design was in randomized blocks, in a 3 x 4 factorial scheme, corresponding to the three factors for growth promotion (negative control: water; Osmocote® slow-release fertilizer and a Bacillus spp. bacterium) subjected to four levels of irrigation water salinity (S1 = 0.5; S2 = 1.5; S3 = 3.0 and S4 = 4.5 dS m-1), and five blocks, totaling 60 experimental units. Sixty days after transplanting (DAT) and application of treatments, the following variables related to plant growth were measured: number of leaves (NL), pseudostem diameter (PD), plant height (PH), leaf area (LA), and root length (RL). The rise in saline levels in the irrigation water negatively influenced the variables number of leaves, pseudostem diameter, root length, and leaf area, showing a decreasing linear behavior. The variables number of leaves and leaf area of seedlings inoculated in association with Bacillus spp. did not differ from each other, regardless of the saline level. This indicated a likely increase in the response to the salinity tolerance of the seedlings. Treatment with Osmocote® fertilizer differed statistically for variables plant height, pseudostem diameter, and leaf area.

Precision agriculture in the Internet of Things (IoT) integrates different technologies able to raise crop productivity, optimize resource efficiency, and accelerate decision making. However, the adoption of this technology is usually costly, affecting the acquisition by the farmers. Thus, the objective of this work was to develop and evaluate low-cost hardware to obtain data in a hydroponic system via IoT. The experiment was conducted at the Pici Campus of the Federal University of Ceará and split into three distinct stages. Firstly, the DS18B20 temperature sensors were calibrated in water, using the KR380 infrared thermometer as a comparison method. For the second step, when the hydroponic system was installed, the water temperature was monitored in the channel and not in the solution reservoir. In this same phase, the quality of data sending and receiving was investigated. In the third step, the sensory data were analyzed with those obtained by the local Meteorological Station. The calibration results revealed that the DS18B20 sensor has reasonable accuracy and excellent agreement and reliability between data. As for receiving and storing, only 6% of the total data was lost.

The evaluation and monitoring of the performance of irrigation systems are crucial in maintaining water efficiency and conservation of water and energy resources. Therefore, the objective of this study was to develop and validate an application for the coefficient of uniformity coordinators of pressurized irrigation systems. So, the UniIrrig® application was developed, using the integrated development environment Android Studio10 version 4.0.1, in JAVA language, with applicability in devices with the Android operating system. For quantitative verification, the same input values in the UniIrrig® application were also inserted in Microsoft® Excel 2010, in all uniformity conductors used in the application. For the qualitative analysis, together with the experience of the user, 68 students of the Agronomy course at the Federal University of Ceará (UFC) participated in tests in order to evaluate the perception of usability, design, usefulness, and general satisfaction of the tool. To validate the application in the field, a uniformity test was carried out on a center pivot in the municipality of Cascavel, Ceará state, with the aid of collectors (Kit Fabrimar) to deliver the applied depth and the consequent result of the distribution uniformity coefficient (DUC), of Hart (HDC) and weighted mean depth analysis. These values were compared to the results obtained in Microsoft® Excel 2010. The dynamic analysis of the data evolved in “r”= 1, thus providing perfect adaptation between the results obtained by the application and by Microsoft® Excel, finding an error equal to zero. In the qualitative assessment, 84.1% consider the application a good tool for coefficient determination. It is concluded that the UniIrrig® application, designed for the Android operating system, can be used to quantify the assessed irrigation uniformity coefficients.

The objective of this work was to evaluate the response of the soil moisture resistive sensor HL-69 to different substrates. The study was split into two experiments. These were conducted at the Hydraulics and Irrigation Laboratory of the Agricultural Engineering Department of the Federal University of Ceará. Forty polyethylene vases with a capacity of 1030 mL were used, arranged on a benchwork. The treatments corresponding to the substrates were T1 (soil + commercial substrate (1: 1)); T2 (soil + hydroretainer (2 g kg-1); T3 (soil) and T4 (commercial substrate), with ten replicates per treatment. The readings of the Hl-69 sensors were carried out simultaneously with the weighing of the vases on an analytical scale. According to the most promising response, the second experiment was started with the adoption of the T3 treatment. The readings carried out in this work followed two different methodologies: Firstly, readings of the saturation condition until low moisture (wet-dry) were obtained, and later they were obtained from the low moisture point to saturation (dry-wet). The Hl-69 sensor shows poor performance in determining the water content in the adopted substrates, showing better performance for the T3 treatment. The methodology that obtained the best adjustment of the data was the soil readings in the wetting process (dry-wet).

O objetivo deste trabalho foi avaliar o efeito de diferentes biofertilizantes como também das cultivares de Feijão-Fava no comportamento das variáveis de matéria fresca e seca da folha e do caule da cultura (MFF, MFC, MSF e MSC). Os tratamentos foram dispostos em um delineamento em blocos ao acaso em esquema fatorial 3 x 4 com 3 repetições, constituído de: três cultivares de fava (F1 = Milagrosa, F2 = Espirito Santo, F3 = Orelha de Vó) e quatro biofertilizantes (B = bovino, C = codorna, O = ovino e M = Misto). Cada unidade parcelar foi composta por 2 vasos, contendo 1 planta, totalizando 76 plantas. As análises estatísticas foram realizadas no qual, demonstraram que todas as variáveis apresentaram efeito significativo para o fator biofertilizante. O fator cultivar foi significativo apenas para MSF, enquanto que MFF e MSF apresentaram efeito significativo para a interação biofertilizante x cultivar.