No abstract

No abstract

Water stress compromises plant growth. Resistance inducers, such as potassium silicate (K2SiO3), can reduce negative effects of this stress on Solanaceae, Capsicum annuum. Plant height, stem diameter and leaf area may indicate the efficiency of potassium silicate foliarsprayagainst water stress. The aim of this study was to evaluate the growth of sweet pepper plants under water stress and K2SiO3 doses. The experiment was conducted in randomized blocks in a split-plot scheme in space. The treatments consisted of four soil water stresses: 15 kPa (field capacity), 25 (intermediate value), 35 and 45 kPa (water stress) and three doses of potassium silicate (0, 0.4 and 0.8 L 100 L-1 water), acting as resistance inducers to water stress. The resistance inducer maintained greater heights of the sweet pepper plants, under water stress (35 and 45 kPa) at the initial stage [(20 days after transplanting (DAT)]. Smaller plant diameters were observed at 80 and 100 DAT at 35 and 45 kPa. Sprays using K2SiO3 maintained sweet pepper leaf area with higher values, even under stress condition. The soil water tension from 35 kPa limited, in general, the plant growth. Growth responses in Capsicum annuum to K2SiO3, via foliar spraying, varied according to plant age, as well as the growth parameter considered in this experiment.

Cucumber (Cucumis sativus L) is mostly cultivated by family-based farmers worldwide and processed to pickles by small to mid-sized industries generating employment and income. But irrigation management needs better investigation for adapting adequate sustainable practices. The rational use of irrigation water still has been neglected nowadays, but can improve cucumber production. The objective was to evaluate different irrigation levels on growth and yield parameters of the Amour F1 cucumber hybrid through time under greenhouse. Treatments consisted of five irrigation levels (amounts of water applied of 62, 93, 124, 155 and 186 mm), ranging from water stress to excess water. The experimental design was randomized blocks, with four replications. Vegetative growth and yield showed different responses to the irrigation levels. Plant height and internode length were less influenced by the irrigation levels, throughout the time, than stem diameter and root length. Cucumber yield was low with 62 mm and 93 mm, higher with 124 mm irrigation, and delayed in time at 155 mm and 186 mm. Water excess (186 mm) was not beneficial for pickling cucumber plants, and the amount of 124 mm was satisfactory for their development and yield. The results of this study may allow adoption of sustainable irrigation practices with no waste of agricultural water, a scarce resource worldwide

UTILIZAÇÃO DE BIOSSORVENTE NO TRATAMENTO DE ÁGUAS RESIDUÁRIAS RICAS EM COBRE (II) E SUA REUTILIZAÇÃO NA PRODUÇÃO DE ALFACE     MARA LÚCIA CRUZ DE SOUZA1; JOSÉ ANTONIO RODRIGUES DE SOUZA 2; DÉBORA ASTONI MOREIRA3; JOÃO DE JESUS GUIMARÃES 4; ELLEN LEMES SILVA 5 E JOÃO VICTOR COSTA6   Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas – FCA – Unesp, Câmpus Botucatu, Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu/SP, Brasil, mara_cruzsouza1@hotmail.com Departamento de Engenharia Agrícola, Instituto Federal de Educação Ciência e Tecnologia Goiano-Campus Urutaí, Rodovia Geraldo Silva Nascimento Km 2,5, Zona Rural, Urutaí-GO, Brasil, jose.antonio@ifgoiano.edu.br Departamento de Engenharia Agrícola, Instituto Federal de Educação Ciência e Tecnologia Goiano-Campus Urutaí, Rodovia Geraldo Silva Nascimento Km 2,5, Zona Rural, Urutaí-GO, Brasil, debora.astoni@ifgoiano.edu.br Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas – FCA – Unesp, Câmpus Botucatu, Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu/SP, Brasil, j-jesus.guimaraes15@hotmail.com Departamento de Recursos Naturais do Cerrado, Instituto Federal de Educação Ciência e Tecnologia Goiano-Campus Urutaí, Rodovia Geraldo Silva Nascimento Km 2,5, Zona Rural, Urutaí-GO, Brasil, ellen_cbba@hotmail.com Instituto Federal de Educação Ciência e Tecnologia Goiano-Campus Urutaí, Rodovia Geraldo Silva Nascimento Km2.5, Zona Rural, Urutaí-GO, Brasil, joaovictor0796@hotmail.com     1 RESUMO   Neste trabalho objetivou-se, estudar o tratamento de águas residuárias ricas em cobre por meio de biossorção, bem como o posterior reuso deste biossorvente na produção de alface. Para isso, avaliou-se a capacidade de remoção do cobre (II) pela casca de ovo moída por meio da isoterma de adsorção de Langmuir. Posteriormente, para estudar os efeitos do reuso deste adsorvente, diferentes doses foram adicionadas a vasos cultivados com alface, avaliando-se os efeitos no solo e na planta. Os resultados permitiram concluir que a casca de ovo moída apresentou elevada capacidade de remoção do cobre (25,4291 mg g-1), não havendo contaminação do solo e as plantas de alface apresentaram-se aptas para o consumo. Assim, a bioadssorção e o posterior reuso do adsorvente na produção de alface mostrou-se uma técnica ambientalmente adequada e de baixo custo. Palavras-chave: reuso, bioadssorvente, metal pesado.     SOUZA, M. L. C.1; SOUZA, J. A. R.2; MOREIRA, D. A.3; GUIMARÃES, J. J.4; SILVA, E. L.5; COSTA, J. V.6 USE OF BIOSORBENTS IN THE TREATMENT OF WASTEWATER RICH IN COPPER (II) AND THEIR REUSE ON LETTUCE PRODUCTION         2 ABSTRACT   The present work aimed at studying the treatment of wastewater rich in copper by biosorption, and the subsequent reuse of this biosorbent in the production of lettuce. For this, the capacity of copper (II) removal by the egg shell ground by means of the Langmuir adsorption isotherm was evaluated. Subsequently, the effects of reuse of this adsorbent was studied, and different concentrations were added to pots grown with lettuce, evaluating the effects on soil and plant. The results showed that the egg shell ground presented high copper removal capacity (25.4291 mg g-1), with no contamination of the soil and the lettuce plants were suitable for consumption. Thus, biosorption and subsequent reuse of the adsorbent in the production of lettuce proved to be an environmentally adequate and low-cost technique.   Keywords: reuse, biosorbent, heavy metal.