No abstract

RESUMO: Em face de características relacionadas à infraestrutura, situação edáfica, hídrica e social, peculiares do semiárido brasileiro, é precípua a utilização de sistemas de cultivo alternativos que considerem tais características, inclusive a qualidade da água disponível. Dentro desta lógica, o objetivo do presente trabalho foi avaliar os efeitos do estresse salino sobre as variáveis de produção e pós-colheita de flores de girassóis cultivadas em um sistema hidropônico alternativo de baixo custo. Utilizou-se de delineamento experimental inteiramente casualizado, analisado em esquema fatorial 4 x 3, com três repetições; os tratamentos consistiram na utilização de quatro níveis de salinidade da solução nutritiva (1,7 -testemunha; 4,3; 6,0 e 9,0 dS m -1 ) na produção de três cultivares de girassol (sol noturno, bonito de outono e anão de jardim). Verificou-se que, mesmo sob efeito da salinidade da solução nutritiva até o nível de 9 dS m -1 , o número de pétalas e a duração pós-colheita mantiveram-se dentro dos padrões comerciais para as cultivares "Sol-Noturno" e "Anão-de-Jardim".

No abstract

A B S T R A C TThe increase of water use efficiency in crop production is a clear need in areas with restricted access to this resource and, in these cases, the adoption of forms of cultivation contextualized to local conditions are essential. Thus, the implications of the variation in the amount of seeds per cell (0.5, 1.0, 1.5 and 2.0 g) and spacing between cells (7.0, 10.0 and 15.0 cm) on variables related to consumption and water use efficiency for the production of coriander (cv. Tabocas) in a low-cost hydroponic system, an alternative for semiarid regions, were evaluated. A completely randomized experimental design, analysed in 4 x 3 factorial scheme with three replicates, was adopted, and the data were subjected to analysis of variance at 0.05 probability level. It was found that the reduction in the spacing between cells has a better cost-benefit ratio with respect to water consumption, biomass produced and cost of seeds. Therefore, it is recommended the adoption of a spacing of 7.0 cm between cells and the use of 1.0 g seeds per cell; this configuration promoted efficiency of 81.59 g L -1 in shoot green mass production and total mass of 62.4 g coriander bunches.Eficiência do uso da água na produção do coentro em hidroponia de baixo custo R E S U M O O incremento da eficiência do uso da água na produção das culturas é uma necessidade evidente em regiões com acesso restrito a este recurso e, nesses casos, a adoção de formas de cultivo contextualizadas à realidade local é imprescindível. Neste contexto, avaliou-se as implicações da variação da quantidade de sementes por célula (0,5; 1,0; 1,5 e 2,0 g) e do espaçamento entre células (7,0; 10,0 e 15,0 cm) sobre variáveis relacionadas ao consumo e eficiência do uso da água na produção de molhos de coentro (cv. Tabocas) em um "módulo hidropônico de baixo custo", alternativo para regiões semiáridas. Adotou-se um delineamento experimental inteiramente casualizado analisado em esquema fatorial 4 x 3, com três repetições cujos dados foram submetidos à análise de variância em nível de 0,05 de probabilidade. Verificou-se que a redução dos espaços entre células proporcionou melhor relação custo benefício em relação ao consumo de água, massa produzida e custo de sementes. Recomenda-se, portanto, a adoção de 7,0 cm de espaçamento entre células e a utilização de 1,0 g de sementes célula -1 ; esta configuração proporcionou eficiência de 81,59 g L -1 na produção de massa verde da parte aérea e molhos de 62,4 g de massa total.

Gas exchanges and chlorophyll a fluorescence are ways to physiologically analyze the response of plants to salt stress. In this context, the present work was conducted between August and November 2016 in a greenhouse at the Federal University of Campina Grande (7°12’52” S, 35°54’24” W, mean altitude of 550 m), using bell pepper plants cv. All Big, exposed to levels of nutrient solution electrical conductivity (1.7, 3.7, 5.7, 7.7, 9.7 and 11.7 dS m-1) and cultivated in hydroponic system, spaced by 0.2 and 0.3 m, focusing on the analysis of gas exchanges and photochemical efficiency. The experimental design was completely randomized, in a 6 x 2 factorial scheme, with five replicates. Plant density influenced the sensitivity of the gas exchanges to salinity and, when reduced, mitigated its effects at higher salinity levels. Increasing plant density at high levels of electrical conductivity caused damage to the photosynthetic apparatus and even reduced the levels of efficiency of the photosystem II from 3.98 dS m-1.

PRODUÇÃO E COMPOSIÇÃO MINERAL DO COENTRO EM SISTEMA HIDROPONICO DE BAIXO CUSTO  ANTÔNIO RAMOS CAVALCANTE1; JOSÉ AMILTON SANTOS JÚNIOR2; HANS RAJ GHEYI3; NILDO DA SILVA DIAS4 E VITAL PEDRO DA SILVA PAZ3 1Mestrando em Engenharia Agrícola, UFCG. Campina Grande-PB. E-mail: antonio_soledade@hotmail.com; 2Universidade Federal Rural de Pernambuco. Recife-PE. E-mail: eng.amiltonjr@hotmail.com; 3Núcleo de Engenharia de Água e Solo, Universidade Federal do Recôncavo da Bahia. Cruz das Almas-BA. E-mail: hans@pq.cnpq.br; vitalpaz@ufrb.edu.br; 4Universidade Federal Rural do Semiárido, Mossoró-RN. E-mail: nildo@ufersa.edu.br.  1 RESUMO O coentro (Coriandrum sativum L.) é uma hortaliça amplamente consumida no Brasil, no entanto, em comunidades difusas pelo semiárido brasileiro, ainda é cultivada de forma rudimentar, sem racionalização de insumos como sementes e fertilizantes. Neste contexto, o objetivo deste trabalho foi avaliar os impactos de estratégias de otimização de insumos e suas implicações na produção e composição mineral do coentro (cv. Tabocas) cultivado em sistema hidropônico de baixo custo. Os tratamentos consistiram na utilização de quatro pesos de sementes por célula no semeio (0,5; 1,0; 1,5 e 2,0 g) e três espaçamentos entre células (7,0; 10,0 e 15,0 cm), e foram distribuídos em um delineamento inteiramente casualizado, em esquema fatorial 4x3, com três repetições, totalizando 36 unidades experimentais. Avaliou-se a fitomassa fresca e seca da planta, parte aérea e raiz, bem como os teores de Ntot, P, K, Ca, Mg, Cl e Na na parte aérea, e os resultados foram submetidos a análise de variância. Concluiu-se, portanto, que foi viável a produção do coentro no “módulo hidropônico de baixo custo” sendo recomendada a utilização de 1,0 g de sementes por célula e espaçamento de 7,0 cm entre células, o que significou uma produtividade média de 5,5 kg m-2 de fitomassa fresca da parte aérea. Quanto a composição mineral, verificou-se tendência decrescente do teor de Ca e cloretos em função do incremento do peso de sementes. Palavras-chave: Agricultura familiar, coriandrum sativum L , cultivo em solo.  CAVALCANTE, A. R.; SANTOS JÚNIOR, J.A.; GHEYI, H. R.; DIAS, N. da S.; PAZ, V. P. da S.PRODUCTION AND CONTENT OF NUTRIENTS AND SODIUM OF CORIANDER IN HYDROPONIC SYSTEM OF LOW COST  2 ABSTRACT Coriander (Coriandrum sativum L.) is a vegetable widely consumed in Brazil, however, especially in communities across the Brazilian semiarid, it is still cultivated in a rudimentary way, without rationalization of inputs such as seeds and fertilizers. So the objective of this study was to evaluate the impacts of strategies of optimization   of inputs and their implications in the production and mineral composition of coriander (cv. Tabocas) grown in low-cost hydroponic system. The treatments consisted of four rates of seeds per cell in seeding (0.5, 1.0, 1.5 and 2.0 g) and three spacing between cells (7.0, 10.0 and 15.0 cm ), distributed in a completely randomized design, analyzed in 4x3factorial, with three repetitions, totaling 36 experimental units. The fresh and dry weight of plant, shoot and root, as well as content of Ntot, P, K, Ca, Mg, Cl and Na in the shoot were evaluated, and the results were submitted to analysis of variance. It was concluded that the production of coriander is feasible in the " low cost hydroponic module ". It is recommended the use of 1.0 g of seeds per cell and spacing of 7.0 cm between cells, which means an average production of 5.5 kg m-2 of fresh mass of aerial parts. About the mineral composition, it was found a decreasing trend of Ca and chlorides contents due to the increase in seed weight. Keywords: Family agricultural, Coriandrum sativum L, soilless cultivation.

The viability of the use of brackish water in the hydroponic cultivation of vegetables cannot dispense with auxiliary techniques such as water mixing and the use of plant densities. In this sense, the objective of the present work was to analyze the growth and production of sweet pepper, cv. All Big, under hydroponic conditions, under different levels of electrical conductivity of the nutrient solution (1.7, 3.7, 5.7, 7.7, 9.7 and 11.7 dS•m −1 ) in plants spaced every 0.2 m and 0.3 m. These treatments were distributed in a completely randomized experimental design, analyzed in a 6 × 2 factorial scheme, with five replications. The growth variables were evaluated at 60, 75 and 90 days after sowing and the production variables at the time of harvest; however, the results were submitted to analysis of variance, at a 0.05 probability level. The interaction between the electrical conductivity of the nutrient solution and the density of plants influenced the behavior of the growth and production variables of pepper (All Big). It was verified that the pepper plants had better performance of the biometric variables plant height, stem diameter and number of leaves when cultivated every 30 cm. At the time, in the analysis by plant, the production of pepper fruits was more expressive when spacing of 30 cm was adopted, however, in the tube of six meters, when 20 cm of spacing was used, the number of fruits was on average, 26.38% and 16.40% higher than lower density, in the electrical conductivities 1.7 and 11.7 dS•m −1 .

Water availability is a fundamental condition for sustainable agriculture. However, a satisfactory water condition is not always possible in terms of quantity and quality in certain regions, such as the Brazilian semi-arid region. Thus, the purpose of this extremely important research was to evaluate the growth of cv. All Big with six combinations of wastewater plus saline (WW + SW) and two nutrient solution percentages, in a low-cost hydroponic system. The experiment was carried out in a greenhouse at the Department of Agricultural Engineering at Federal University of Campina Grande. A completely randomized experimental design was used, with treatments arranged in a factorial scheme (6 × 2), with 5 replications, being the treatments composed by the combination of six proportions of wastewater with saline water (50%/50%; 60%/40%; 70%/30%; 80%/20%; 90%/10%; 100% of wastewater) and two nutrient solution concentration (80% and 100%), totalizing 60 experimental units. The biometric variables were analyzed at 55 and 96 days after sowing, namely: plant height (PH), stem diameter (SD), leaf number (LN) and leaf area (LA). The interaction between the concentration of the nutrient solution and the ratio of the saline water with wastewater was influenced in the behavior of peppers (cv. All Big) biometric variables. The nutrient solution prepared at 80% of its normal concentration had better performance in the development of plants when mixed with the proportions of water containing more wastewater. The proportion 30% saline water and 70% wastewater (30/70) with concentration of 80% of the nutrient solution obtained better satisfactory results in the studied biometric variables.