Rendimento e qualidade de melancia cultivada sob proteção de agrotêxtil combinado com mulching plástico

The ground cover is an agricultural practice that is designed mainly to control weeds, while the nonwoven prevents the attack of pests. The objective of this study was to evaluate the yield and fruit quality of watermelon grown under nonwoven textile protection combined with plastic mulching. The experiment was conducted at the WG Fruits Company, Baraúna, RN. A randomized block design was used in a factorial 3 x 3 + 1 with four replications, and 36 plants per plot, with the first factor of color of plastic used in mulching (black, silver and white) and the second factor nonwoven textile with different times of use (first and third crop nonwoven under textile and without nonwoven) and an absolute control (no mulching and without nonwoven). The production variables evaluated were: yield (commercial, noncommercial, and total fruit yield), and fruit quality (soluble solids - SS, titratable acidity - TA and SS/TA). The use of mulching and protection of plants with nonwoven textile provided a higher yield of watermelon fruits in relation to bare soil with and without nonwoven textile protection. Fruit quality was not affected by the use of mulching and nonwoven.

Consumo de combustível de duas colhedoras de cana-de-açúcar em função da velocidade e rotação de motor

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Processamento tecnológico e avaliação energética de geléia de acerola

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caracterização de variedades de amendoim cultivadas em diferentes populações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Densidade de plantio na produção de ervilha-de-vagem

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relação K:Ca:mg na solução nutritiva para o cultivo de mini tomate em substrato

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise energética da madeira e do carvão de híbridos entre Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson e Corymbia torelliana (F. Muell.) K.D. Hill & L.A.S. Johnson

This research aimed to evaluate the wood and charcoal quality of hybrids clone of the crossing C. citriodora with C. torelliana in two different locations for charcoal production. Seven with 3,75 years old clones, planted at country of Itamarandiba – MG, and six 6,42 years old clones, planted in Dionísio – MG, were studied. For wood and charcoal quality analysis, samples were collected along the stem of the trees until the commercial height. Properties study of the wood was done by chemical analysis, basic density, superior heat power, and thermogravimetric analysis. The wood samples were carbonized in laboratory conditions with heating rate of 1.67 0 C.min -1 , starting at 100 0 C until 450 0 C and keeping on this temperature for 30 minutes. It were determined the carbonizations gravimetric yield, all in dry basis. The wood quality was evaluated based on the chemical immediate analysis, relative apparent density, and gross heating value. The experiment was installed according to the completely randomized design, with five repetitions. The collected data were submitted to analysis of variance and, when the evaluated effects were significant by “F” test, was applied the Scott-Knott test at 5% probability for multiple comparisons. For correlation analysis, Pearson correlation coefficient, tested by the "t" test at 5% probability was used. Results showed variability of wood between the genetic materials evaluated in relation to place and plant crossing. The thermal analysis of the wood showed significant variation between clones and it was possible to differentiate two stages of degradation (hemicelluloses and cellulose). The majority of the clones presented satisfactory properties for the charcoal production, while, clone 3, planted in Itamarandiba, obtained the best performance due it have the higher yield and energetic efficiency, thus, achieving the best potential for charcoal production. However, clone 9, planted in Dionísio, was the less indicated for charcoal production since it presented the lowest energetic efficiency, gravimetric yield, and densities.

Determinação da densidade amostral ótima para a geração de mapas temáticos na cafeicultura de precisão

Among the crops commercially exploited in Brazil, the coffee has a great economic importance, especially in the states of Minas Gerais and Espirito Santo. In the search for higher yield and lower environmental impact, farmers and researchers seek to develop new technologies that result in greater efficiency in various production processes of the coffee. For this, the adoption of precision agriculture in the management of operations in coffee crops, called precision coffee, has shown results that justify its use, by identifying the spatial variability of several variables, allowing its localized management and in the proper intensity. Unlike conventional management that is based on the average of observations in an area, precision agriculture uses a more detailed sampling, based on a sampling grid, which allows to represent in greater detail the reality of farming. Many previous studies have identified the spatial variability of the production of coffee system variables, but without worrying about the quality of information obtained due to the sampling grid used as precision and accuracy. Given the above, the objective of this study was to evaluate the quality of four different sampling grids for different variables and three times, in order to identify the most appropriate grid for use in precision coffee. Also aimed to compare the results between the precision coffee and conventional, according to reference values.

Utilização do óleo extraído dos resíduos da filetagem de tilápia (Oreochromis niloticus) para produção de biodiesel

The aims of this study were to evaluate the potential of the oil extracted from tilapia residues filleting for biodiesel production, select the one that presents the greatest potential for this purpose and characterize the obtained biodiesel to be neutralized or refined and analyzed according to their physicochemical and yield characteristics. For this, the crude heads, carcasses and offal which have undergone physical and chemical analysis and yield were extracted. For this, the crude oil was extracted from the heads, carcasses and guts, which have passed through physicochemical and yield analysis.For the statistical analysis, a completely randomized design was used with 3 treatments (head, carcass and viscera) and 5 replications.It was observed significant differences in the oils (P <0.05) being the viscera oil the one that showed higher yield although it presented the worst values for all evaluated indices. For this reason this oil was selected for further studies. In this new stage of the study the treatments were: neutralized crude oil and viscera refined oil with different volumes of NaOH 16%.It was adopted a completely randomized design, with a 2x3 factorial (types of oil x soda volumes) with 3 replications. The analyzed variables were acid value, saponification index, peroxide value and iodine value. It was also evaluated the performance of all the obtained biodiesel. It can be concluded that: among the filleting residues oil of tilapias, the one which is more suitable for biodiesel production, due to its high yield, was the viscera oil. The use of all stages of refining is indispensable, once the obtained index and the yield were greater in the biodiesel refined oil; the produced biodiesel from tilapia’s viscera oil meets the ANP standards and, therefore, it is adequate for use.

Comportamento de cultivares de arroz de terras altas em função do preparo do solo e irrigação por aspersão, em latossolo vermelho de cerrado

Pós-graduação em Agronomia - FEIS

Enxertia, potássio e magnésio na nutrição, desenvolvimento e produção de pepino

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produtos de efeitos fisiológicos no desenvolvimento de plantas de tomate ‘giuliana’, na produção e pós-colheita de frutos

Pós-graduação em Agronomia (Horticultura) - FCA

Estudo das variáveis operacionais dos processos de separação na produção de biodiesel, a partir do óleo de palma bruto (Elaeis guineensis, Jacq) em escala de laboratório

Neste trabalho investigaram-se de forma sistemática as variáveis operacionais de processo envolvidas nas operações de separação aplicadas no pré-tratamento do óleo de palma bruto (Elaeis guineensis, jacq) e na purificação do biodiesel produzido via transesterificação etanólica utilizando NaOH como catalisador, em escala de laboratório. Na etapa de pré-tratamento foram investigados os processos de Filtração e Decantação, sendo a filtração do produto da neutralização realizada a 40ºC, 50ºC e 60ºC, enquanto que na Decantação, avaliaram-se as temperaturas de 40ºC e 60ºC em 120 minutos. Em seguida, investigou-se a influência do tempo de decantação de 60, 90 e 120 minutos no processo de lavagem do óleo neutralizado a 40ºC e 60ºC, seguida de Desidratação sob vácuo a 80ºC, tendo sido investigado nesta etapa a influência da pressão. Após a reação de transesterificação, avaliou-se o processo de Evaporação do etanol em excesso, onde em um primeiro momento investigou-se as temperaturas de 70 e 80ºC, mantendo-se o tempo de evaporação constante em 20 minutos, no intervalo de 613,30 a 80,00 mbar, e em um segundo momento analisou-se as pressões de operação de 480,00 e 346,66 mbar. Em seguida, investigou-se a influência do tempo no processo de decantação da fase rica em glicerol a 70ºC, para tempos de 60, 120 e 180 minutos. Sendo realizada a lavagem da fase rica em ésteres a 70ºC, para os tempos de 60, 90 e 120 minutos de decantação da água residual. Avaliou-se ainda a eficiência do processo de centrifugação da mistura biodiesel e glicerol a 60 e 70ºC a 2000 rpm, para um tempo de 15 minutos. Em seguida, procedeu-se a lavagem da fase rica em ésteres com água a 60 e 70ºC, sendo a separação realizada via centrifugação a 60 e 70ºC. As fases ricas em ésteres, obtidas via decantação e centrifugação, foram submetidas à Desidratação sob vácuo, e caracterizadas em conformidade com as especificações da ANP. De acordo com os resultados experimentais, com base na qualidade do óleo neutro e rendimento do processo, observou-se que a Filtração a 50ºC gerou os melhores resultados para o pré-tratamento do óleo. Em relação à Evaporação do etanol, o melhor percentual de recuperação foi obtido a 80ºC e 346,6 mbar. Com relação à separação da fase ricas em ésteres e glicerol, o processo de Centrifugação a 60ºC gerou um biodiesel de melhor qualidade e maior rendimento. Observou-se ainda, a necessidade de uma segunda etapa de centrifugação de forma a minimizar a perdas de biodiesel na fase rica em glicerol.

Caracterização de extratos de cajá-manga (Spondias dulcis Parkinson) potencialmente ativos e seguros para obtenção de fitocosmético antioxidante

Pós-graduação em Ciências Farmacêuticas - FCFAR

Uso de paclobutrazol em tomateiro cultivado em dois ambientes

Pós-graduação em Agronomia - FEIS