Production and quality of mini watermelon cv. Smile irrigated with saline water

A B S T R A C T The purpose of this study was to evaluate the salt tolerance of mini watermelon (cv. Smile). ). Aos 85 dias após o início do experimento avaliaram-se as plantas e as variáveis físico-químicas dos frutos. A salinidade afetou negativamente as variáveis comprimento do ramo principal, diâmetro do caule, número de folhas, número de ramos secundários, área foliar, massa fresca e massa seca. Para as variáveis físico-químicas dos frutos a salinidade reduziu a massa fresca, o diâmetro e o pH do fruto e elevou o teor de vitamina C. Com os resultados obtidos infere-se que a minimelancia cv. Smile é moderadamente sensível à salinidade

Production and quality of mini watermelon cv. Smile irrigated with saline water

ABSTRACT The purpose of this study was to evaluate the salt tolerance of mini watermelon (cv. Smile). The experiment was carried out in the greenhouse of the Department of Biosystems Engineering of ESALQ/USP. The experimental design was randomized blocks. The plants were irrigated with five levels of salinity (S1 = 1.0; S2 = 2.0; S3 = 3.0; S4 = 4.0 and S5 = 5.0 dS m-1). At 85 days after the beginning of the experiment, the plants and the physical and chemical variables of the fruit were evaluated. Salinity negatively affected the variables: length of the main stem, stem diameter, number of leaves, number of branches, leaf area, fresh and dry matter. Regarding the physical and chemical characteristics of fruits, salinity reduced the mass, diameter and the pH of the fruit, but increased its vitamin C content. In general, the results suggest that the mini watermelon (cv. Smile) is moderately sensitive to salinity

A proposed index to assess quality of waters from desalination plants

ABSTRACT Reverse osmosis is the technology commonly used to produce fresh water from brackish groundwater. Due to the reject brine generated in desalination plants by reverse osmosis, vulnerability assessment to define critical areas to monitor waters from desalination has been an important tool for delineating the monitoring networks required for surveillance of potential salinization sites. The objective of this study was to assess the quality of waters sampled in desalination plants by a quality index, which provides a relative assessment of water vulnerability to potential salinization. The present study proposes an index to assess the quality of waters from desalination plants initially using the chemical parameters electrical conductivity, sodium adsorption ratio, Mg2+/Ca2+ ratio, and the ions sodium, chloride and bicarbonate. The index to assess quality of waters from desalination plants showed good performance and can include additional parameters referring to the soil and crop exploited. High values of the relative index of quality of waters from desalination plants are considered as possible indicators of risk of soil salinization and groundwater contamination. The highest level of land use impact on the quality of waters from desalination plants was found in reject brine samples followed by well water samples

Chemical attributes of traditional agriculture and Caatinga managed at different depths in an Inceptisol

ABSTRACT The objective of this work was to evaluate changes in the chemical attributes of an Inceptisol in two areas of sustainable management of the Caatinga Biome and a conventional tillage, compared with the native forest. The areas were managed in the following way: in areas under sustainable management, the Caatinga was thinned in a savanna system (1), and in the other area, the Caatinga was thinned in strips (2); the area under conventional tillage was burned, plowed and harrowed (3), and the native forest (4). The following chemical attributes were analyzed: pH, electrical conductivity, Ca2+, Mg2+, H + Al, P, Na+, K+ and soil organic matter (SOM), calculating CEC and base saturation. The treatments were evaluated using multivariate analysis, at different depths up to 0.52 m. In the Caatinga areas thinned in a savanna system and in strips, the greater availability of exchangeable bases and SOM occurs close to the depth of 0.20 m and, in the area with traditional agriculture, it is limited to 0.10 m. In the area thinned in a savanna system, sodium showed a negative correlation with the other elements

Foliar content of N, P and K in cotton fertigated with treated sewage effluents

El objetivo de este trabajo fue evaluar los efectos del riego con efluente de alcantarillado tratado en el contenido foliar de nitrógeno, fósforo y potasio en el cultivo de algodón (Gossypium hirsutum L. cultivar 8H) en dos tipos de suelos. El experimento fue llevado a cabo en el Campus de la Universidad Federal del Semi-Árido en Mossoró, Brasil. El diseño experimental empleado fue el de bloques al azar con parcelas subdivididas. Los tratamientos consistieron en diluciones del efluente de alcantarillado en agua de abastecimiento [25, 50, 75, 100% de efluente y tratamiento agua de abastecimiento + fertilización mineral del suelo - control] en dos tipos de suelos con diferentes texturas (Latossolo Vermelho Amarelo y Cambissolo). Se concluye que el uso de aguas residuales suple las necesidades nutricionales del cultivo de algodón en lo referente al N y K, excepto para el P.The objective of this study was to evaluate the effects of irrigation with treated sewage effluent in the leaf content of nitrogen, phosphorus and potassium in cotton (Gossypium hirsutum L. cultivar 8H) growing in two soil types. The experiment was carried out on the campus of the Federal University of the Semi-Arid Mossoró, Brazil. The experimental design was a randomized block with split plots. Treatments consisted of dilutions of domestic sewage effluent with water-supply [25, 50, 75 e 100% effluent and, water-supply + mineral soil fertilization - control] in two different types of soils textures (Oxisol and inceptisol). We conclude that the use of treated sewage effluent supplies the nutritional needs of growing cotton in relation to N and K, except for P