Análisis de los beneficios económicos de un servicio de asesoramiento al regante (SAR)

Un Servicio de Asesoramiento al regante (SAR) tiene como objetivo principal la optimización del uso del agua en la agricultura, dando respuesta a las demandas tecnológicas de los regantes. El objetivo de este trabajo es analizar y cuantificar, para una parcela tipo de cebolla, los beneficios económicos de un Servicio de Asesoramiento al Regante (SAR), a través de un análisis comparativo de distintos manejos del riego en parcela. En el año 2015, en una parcela de cebolla ubicada en una Comunidad de Regantes (CCRR) de la provincia de Albacete se realizó el seguimiento del desarrollo fenológico del cultivo, y de la humedad en el suelo, que junto con los datos edáficos y climáticos permitió planificar la programación de riegos. Se plantearon cuatro escenarios comparativos: E1 (datos reales de manejo de riego en parcela), E2 (simulación tomando como referencia las recomendaciones semanales del SAR de Castilla-La Mancha (SIARCM), E3 (simulación con igual aporte que en el E1, variando la frecuencia y la dosis de riego) y E4 (simulación de riego optimizado realizando un Balance de agua en el suelo con el módulo de programación de riegos del programa MOPECO). Los costes de producción del cultivo se calcularon a partir de los datos facilitados por el agricultor, permitiendo interpretar indicadores tales como: el Suministro Relativo de Agua, Índice de Producción, Margen Bruto y la Productividad Agronómica del Agua. Los resultados indican que frente a un manejo sin seguir las recomendaciones de un SAR, los datos facilitados por el SIARCM y una correcta programación pueden influir en un aumento de hasta 24% del rendimiento, una mayor Productividad Agronómica del Agua (8,45 kg/m3 respecto a real obtenida de 7,14kg/m3) y un incremento del Margen Bruto de hasta un 50%

Using BOX and ERIC-PCR to differentiate Fusarium decemcellulare isolated from guarana plant.

Resumo:649-2

Changes in soil fertility and mineral nutrition of mango orchards in São Francisco Valley, Brazil.

This research aimed to analyse the soil fertility changes and macronutrient concentration in mango plantations in Petrolina, Pernambuco, Brazil. Samples of soil were collected at depths of 0-20 and 20-40 cm, and leaves of mango trees during vegetative growth were collected from 11 areas with different cultivation time spans (6, 7, 8, 9, 10, 11, 14, 16, 17, 19, and 26 years). Nearby areas under natural vegetation were sampled for reference. The chemical characteristics of soil evaluated were: pH; P, K, Ca, Mg; exchangeable Na and Al; H + Al; organic matter; sum of bases; base saturation; and total cation exchange capacity. The mango leaves were analysed for N, P, K, Ca, and Mg. The agricultural management practices adopted by the mango-producing companies promoted changes in soil fertility when compared with the reference areas. The concentrations of organic matter tended to increase in the crop areas. The organic matter caused increases in CEC and nutrient retention. High P values were observed in soils and plants owing to the excessive use of fertilizers. This may cause nutritional imbalance and contamination of water sources. The contents of N, P, K in the leaves of mango trees were nutritionally adequat

Sources of resistance in accessions of Cucurbita spp. to virus species from the genus Potyvirus.

The identification of source of resistance in cultivated cucurbits species is very important for the development of resistant cultivars to control diseases caused by virus from the genus Potyvirus. The present research had the objective to evaluate the phenotypic reactions and the behavior of pumpkin (Cucurbita spp.) accessions to the virus species from the genus Potyvirus: Papaya ringspot virus type Watermelon (PRSV-W), Zucchini yellow mosaic virus (ZYMV) and Watermelon mosaic virus (WMV). Twenty-eight accessions of pumpkin from the Cucurbit Germplasm Bank from Embrapa Semiárido, Petrolina, PE, Brazil were evaluated. Twelve young plants from each pumpkin accession were inoculated with each one of the virus species and were maintained at greenhouse for their symptom reaction evaluations. All possible virus infections or absence of infection were confirmed by plate-trapped antigen enzyme linked immunosorbent assay (PTA-ELISA) against antisera specific to PRSV-W, ZYMV and WMV at the Plant Virus Laboratory, Universidade Federal do Ceará. Three pumpkin accessions showed extreme resistant to WMV and eight accessions presented mild mosaic when inoculated with PRSV-W. The most severe symptoms were observed on those accessions inoculated with ZYMV and 50% of the accessions showed to be highly susceptible. On the other hand, the pumpkin accessions inoculated with WMV presented the mildest symptoms, indicating that 39% of them were resistant, and 39% were tolerant. The Cucurbita spp. accessions BGC 518, BGC 530, BGC 567, and BGC 683 that showed resistance to one or more than one virus species constitute promising sources of resistance for developing virus resistant pumpkin cultivars or hybrids

Aceitabilidade de dez cultivares e uma linhagem de feijão-caupi (Vigna unguiculata (L.) Walp) crus e processados.

Este trabalho teve como objetivo avaliar sensorialmente onze cultivares de feijões-caupi (BRS Aracê; BRS Cauamé; BRS Guariba; BRS Itaim; BRS Juruá; BRS Novaera; BRS Potengi; BRS Tracuateua; BRS Tumucumaque; BRS Xiquexique e uma linhagem MNCO5?828C- 3-15) crus e processados. Os grãos crus foram apresentados em sacos de polietileno e os grãos processados tipo conserva em frascos de vidro e avaliados quanto aos atributos cor do grão, cor do anel do hilo, tamanho, formato, aceitação global e intenção de compra. Para feijões crus, os avaliadores preferiram os grãos de cor branca, pois apesar de apresentarem diferenças significativas a cultivar BRS Potengi, mostrou média que em termos práticos acarretou em maior aceitação dos provadores, confirmado pela intenção de compra. Nos feijões processados constatou-se que com relação às características da cor do grão, aceitação global e intenção de compra o tratamento BRS Tracuateua apresentou p<0,05; com relação ao formato e o tamanho as amostras significativas foram, respectivamente, BRS Aracê e BRS Juruá. No entanto, a cor do anel do hilo para as cultivares analisadas não houve diferença significativa. De acordo com os resultados obtidos pode-se verificar que os feijões crus obtiveram maior preferência dos avaliadores para os feijões de cor branca, porém, nos processados essa aceitação incluiu os grãos verdes, confirmando potencial mercado para estes grãos.CONAC 2012. Disponível em: http://www.conac2012.org/resumos/pdf/195a.pdf. Acesso em: 06 ago. 2013

Ensaio de competição entre cultivares de sorgo granífero para região sudeste de Minas Gerais.

O sorgo granífero é uma das culturas que vêm apresentando significativo aumento de produtividade e área plantada no Brasil, por isso surge à importância de melhores cultivares para o mercado. O trabalho teve o objetivo de avaliar a produtividade de grãos de 25 híbridos de sorgo granífero, sendo 22 provenientes do programa de melhoramento genético da Embrapa Milho e Sorgo e três cultivares comerciais, em um experimento no delineamento em blocos ao acaso com três repetições, avaliados na Estação Experimental da Embrapa Milho e Sorgo em Sete Lagoas/MG. Para a avaliação estatística, foi realizada a análise de variância e teste F no programa Genes, e para a realização de agrupamento de médias, foi realizado o teste de Scott & Knott (1974). De acordo com as avaliações, os genótipos 0987014 e 0987028 apresentaram desempenho superior na maioria dos caracteres avaliados, se destacaram e poderão ser recomendados para o cultivo na região sudeste do Estado de Minas Gerais, após validação de seu valor de cultivo e uso em mais locais e anos

Variabilidade genética de Fusarium decemcellulare isolado de três diferentes sintomas em guaranazeiro (Paullinia cupana var. sorbilis).

O objetivo deste trabalho foi analisar a variabilidade entre isolados obtidos de diferentes genótipos de guaranazeiro e de diferentes sintomas.Resumo:57-2

Identification of phenolic compounds in pomegranate (Punica Granatum) seeds and soybean (Glicine Max) oils and its stabilization by spray drying.

Pomegranate seed oil (PSO), even though highly sensitive to oxidation, has been extensively studied due to its bioactive potentials, assigned to the punicic acid, a polyunsaturated fatty acid, and several phenolic compounds. Combined with soybean oil (SO) we get an affordable product, rich in essential fatty acids. In this study we evaluate PSO and SO for phenolic and fatty acids compositions and encapsulate it by spray drying to increase its shelf life. Modified starch, maltodextrin and gum arabic are evaluated by a mixture design to get the better wall material composition. The content of punicic, a conjugated linolenic acid, and linoleic acids in PSO and SO were, respectively 75% and 54%. As expected, the phenolic acids were found at low concentration in PSO and SO, but in high content in pressing cake. The better response for spray drying process yield and oxidative stability were achieved at using modified starch and gum arabic at the same proportion as wall material.Food: the tree that sustains life

Impact of cropping season temperature combined with water deficit on sorghum cultivar development.

Increased temperatures and altered precipitation patterns with severe drought are among the main challenges in agriculture. Hence, this study evaluated the impact of cropping season temperature combined with water deficit on the vegetative performance of sorghum cultivars. The experimental design was randomized blocks in a 2x6x4 factorial arrangement, performed in two annual cropping seasons (one in June -moderate temperatures; and one in January -high temperatures, in Brazilian climate conditions), using six sorghum cultivars (AGRI002E, BRS 506, BRS 716, SF 15, Santa Elisa, and BRS Ponta Negra) at four soil water availabilities (25, 50, 75, and 100% field capacity), with four repetitions. The biometric assessments of plant development (plant height, the number of leaves, stem diameter, and the number of tillers) occurred at the beginning of the maturation phase. The data were subjected to the analysis of variance by the Scott-Knott test and regression for water availability. Sorghum cultivars responded differently to the combined stress of increased air temperatures in different cropping seasons and water deficit. The warmest season was more beneficial to plant height, the number of leaves, and stem diameter. The combined effect of water restriction and temperature harmed the biometric responses of sorghum plants, potentially reducing plant development and final yield