Márcia Rejane de Queiroz Almeida Azevedo

Influência das embalagens e condições de armazenamento no vigor de sementes de gergelim

No Brasil, os problemas de armazenamento sao serios e as perdas, nessa fase, consideraveis. A qualidade fisiologica das sementes enquanto armazenadas deve ser avaliada, sob pena de nao se obter a produtividade desejada. O presente estudo foi desenvolvido tendo como objetivo a analise do vigor de sementes de gergelim (Sesamum indicum) depois de armazenado durante seis meses, em condicoes controladas (câmara seca) e condicoes ambientais de Campina Grande, PB, acondicionadas em embalagens de sacos de papel, sacos de plastico e recipientes metalicos. A pesquisa mostrou que o vigor nao apresentou diferencas significativas para as duas condicoes de conservacao estudadas. O maior vigor apresentado foi das sementes acondicionadas em embalagens impermeaveis.

Cultivo hidropônico de cultivares de alface em soluções nutritivas organominerais otimizadas com a ferramenta SOLVER

The study aimed to evaluate the cultivation of lettuce varieties in floating type hydroponic system with nutrient solutions optimized by the SOLVER tool of the Microsoft Office Excel. The experiment was conducted at the Center of Environmental and Agricultural Sciences Center of the Paraiba State University, adopting an entirely randomized experimental design arranged in factorial scheme 4 x 3, with three repetitions. The factors were 4 nutritient solutions (S1 = 100% mineral solution; S2 = 90% mineral solution + 10% organic solution; S3 = 84% mineral solution + 16% organic solution and S4 = 78% mineral solution + 22% organic solution) and 3 lettuce varieties (C1 - Crespa; C2 - Monteiga and C3 - Ruby). The plant height, stem diameter, number of leaves, the length of the root, fresh matter weight and the dry matter weight of the lettuce were evaluated. The organominerals solutions promoted a greater resistance to variation of the pH and replaced partially the mineral solution. The best biometric and production means were observed for the Crespa and Monteiga varieties and for the mineral solution, mineral solution + 10% of organic solution and mineral solution + 22% of organic solution.

O modelo SASIS: validação da simulação da irrigação por sulco

The aim of this research was to validate the simulation of furrow irrigation performed by the SASIS model through the mathematical procedure of kinematic waves. In the validation of the SASIS model, 7 data sets representing different field conditions were used, in which the furrow length varied from 67 to 403 m, the field slope from 0.0016 to 0.0173 m m-1, the inflow from 1.1 to 2.0 L s-1 and the soil texture type from sandy loam to silty clay loam. In order to give more consistency to the validation, the simulations accomplished by this model were compared with those from the SIRMOD model, and also compared with data from the field measurements. For most field data studied, the simulations of the advance phase by SASIS model presented discrepancies in the advance time at the end of the area, being inferior to the ones given by SIRMOD model, in relation to field measurements. Again, for the greater part of field conditions analyzed, the discrepancies between the values simulated by SASIS model and those measured in field of the advance time at the end of the area were small, to the point of not compromising the prognostic of design, evaluation and management parameters of furrow irrigation systems.

Effects of the Irrigation with Treated Wastewater on Fodder Corn Production

The objective of this research was to analyze the effects of the treated wastewater and of the residual nitrogen manuring on the production of the AG 1051 hybrid fodder corn with straw, without straw and in grains. The experiment was conducted in the Sewers Treatment Station of Campina Grande city, Paraiba state, Brazil, in randomized blocks design with factorial scheme (2 x 5) + 2, having as factors two types of irrigation water (water of provisioning and treated wastewater), five doses of nitrogen (0, 60, 90, 120 and 180 kg N ha-1 and foundation manuring with P and K), and two controls (water of provisioning and treated wastewater), with four replications. The results showed that there was linear increase of the production as a function of the increase of the incorporated doses of nitrogen into the soil and although that the irrigation with treated wastewater promoted an increment of the productivity of 144% in relation to the productivity reached with the water of provisioning.

FIELD EVALUATION OF WATER INFILTRATION PROFILE IN OPENED AND BLOCKED FURROW IRRIGATION WITH CONTINUOUS FLOW

A better water application unifomity along the field would satisfy the crop water needs and stil improve the performance of furrow irrigation systems. The variations on water advance time along the furrow irrigation are mostly responsible for variations on infiltration opportunity time, which result on non-uniform water infiltration profile. The purpose of this research was to observe the behavior of the water infiltration profile in opened and blocked furrow irrigation with continuous flow. Employing a site-specific water application time for both furrow conditions (opened and blocked), field evaluation meassurements were performed in eight furrow irrigation systems from the Sao Goncalo irrigation district, Brazil. The results showed that in opened furrows the differences between the water depths infiltrated at the beginning and at the end of the field were much larger than in blocked furrows. Actually, the infiltrated water depths at the end of the field in blocked furrows were from 12.14 to 96.41% larger than in opened furrows. In blocked furrows, for some cases where the infiltration rate was lower, the infiltrated water depths at the end of the field were larger than at the beginning of the field, allowing a more adequate management strategy with a smaller water application time; consequently, the water uniformity distribution in blocked furrows increased from 4.95 to 23.2%.

Economic Viability and Profitability of Lettuce in Hydroponic System Using Different Effluents

The hydroponic cultivation Lactuca sativa L. can offer producers greater economic profitability, fast financial return due to sanitary and nutritional quality. The objective of this study was to analyze the economic feasibility and profitability indicators of three cultivars of curly lettuce in a hydroponic system using different effluents and well water. The experiment was conducted in a protected environment of the State University of Paraiba-UEPB, Campus-II, in the municipality of Lagoa Seca-Paraiba. Experimental design was in a randomized blocks with plots subdivided in a 7 × 3 factorial scheme, with three replications whose factors were 7 hydroponic solutions and three lettuce cultivars. Variables analyzed included gross revenue; gross margin effective and total operating cost; gross margin total cost of production; leveling point effective operating Cost, total production; operating profit and profitability index. The cultivars: Veronica, Vanda and Thais presented the highest gross revenue and profitability index when irrigated with the Furlani solution (S 1 ).

Monitoring, calibration and maintenance of optimized nutrient solutions in curly lettuce (Lactuca sativa, L.) hydroponic cultivation

The monitoring, calibration and maintenance of nutrient solutions are fundamental for the development of hydroponic lettuce. This study aimed to monitor temperature, electrical conductivity, hydrogen potential and consumption of nutrient solution, besides evaluating the effectiveness of the Microsoft Office Excel solver tool in the calibration of different mineral and organomineral nutrient solutions in the NFT hydroponic cultivation of curly lettuce. The experiment was conducted in randomized blocks with three replicates and the treatments consisted of four mineral solutions proposed by Furlani, Bernardes, Ueda and Castellane and Ara jo, besides four organomineral nutrient solutions, proposed in this research, with chemical composition similar to the previously cited ones. For 24 days, the nutrient solutions were monitored and the variations of temperature, pH, electrical conductivity (EC) and nutrient solution consumption by the crop were measured. Calibrations were made using the Microsoft Excel SOLVER tool, using as reference an EC of 1.5 dS m-1 and nutrient solution volume of 17 L. During the experiment, regardless of the nutrient solution (modified and mineral), temperature showed maximum and minimum values of 28.7 and 21.5 degreesC, respectively, and pH variation was lower in the modified nutrient solutions. Water consumption was higher with the use of mineral solutions, in comparison to the organomineral solutions with the same chemical composition. The SOLVER tool was efficient and easily used in the calibration and maintenance of electrical conductivity and volume of the nutrient solutions.

Production of lettuce genotypes in hydroponic system using different organo-mineral nutrient solutions

Mineral solutions are widely used in hydroponic cultivation but little is known about the use of organo-mineral solutions. With this focus, the present study aimed to evaluate the production of three green-leaf lettuce genotypes (Thais, Vanda and Veronica) in eight nutrient solutions, in NFT hydroponic system, set up in gutters. Four mineral solutions were used in this experiment, referred to as the respective names of the authors (Bernardes, Furlani, Castellane and Araujo, and Ueda). Moreover, four organo-mineral solutions (using biofertilizers in their formulation) were applied, totally eight nutrient solutions. The experiment was carried out in randomized blocks in split plots with three replicates. The main plots consisted of eight nutrient solutions and three lettuce cultivars were assigned in subplots (including six plants per subplot). Lettuce production was evaluated 25 days after transplanting, through the determination of shoot fresh phytomass (SFP), root fresh phytomass (RFP), shoot dry phytomass (SDP) and root dry phytomass (RDP). Production variables were not influenced by the interactive effect of the studied factors. Individually, the nutrient solutions influenced the production parameters and there was variation among the lettuce cultivars only for root fresh phytomass. Higher commercial production of lettuce was obtained with the mineral solutions of Bernardes, Furlani, and Castellane and Araujo.

Economic viability of lettuce (Lactuca sativa, L.) grown in hydroponic system with different optimized nutrient solutions

Hydroponic cultivation is characterized by high initial costs compared with conventional cultivation. This study discusses the economic viability of implementing a hydroponic system for lettuce production with different mineral and organomineral nutrient solutions through simulation. The experimental design was randomized blocks with split plots and three replicates. Plots consisted of eight nutrient solutions: four mineral solutions, with chemical compositions proposed by Bernardes, Castellane and Araújo, Furlani, and Ueda, and four solutions with chemical compositions similar to those previously cited, but modified in the present research with the utilization of biofertilizer in the composition, to produce four organomineral nutrient solutions. Subplots consisted of three varieties of curly lettuce: Verônica, Vanda and Thaís. After harvesting, lettuce plants were separately weighed according to the treatments and, from this information, the selling price was determined based on research conducted in major supermarkets in the city of Campina Grande, Paraíba, Brazil. The calculation of expenses took into account the effective operating cost, total operating costs and the total production cost. According to the simulation, regardless of the cultivar used, lettuce hydroponic cultivation had higher annual profit, with values of US

Simulation and Optimization of Furrow Irrigation by the Model SASIS: Sensibility to the Spatial and Temporal Weighted Factors

18,880.00 and 18,730.00, using the mineral nutrient solutions of Furlani and Bernardes, respectively. Among the organomineral nutrient solutions, the Furlani solution when used in the production of the cultivar Verônica led to annual profit of US