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A Real Option Analysis applied to the production of Arabica and Robusta Coffee in Ecuador

  • Jácome, Andres R.
  • Garrido, Alberto
The coffee market is distinguished for being volatile and uncertain in terms of domestic and international prices. Arabica and Robusta coffee are produced in 23 provinces of Ecuador. A decade-long decline of coffee production prompted the Ecuadorian government to launch a public program for replanting coffee trees towards the end of 2011. A grower’s decision to enter, remain in or exit the coffee sector is based on fluctuating profits from each year’s harvest sale. We analyzed the hypothesis whereby the coffee grower’s decision to leave the sector is explained by volatile and uncertain prices. This paper aimed to evaluate the coffee sector with an application of Real Option Analysis for the period 2002-2012. We also defined entry (H) and exit (L) prices for Arabica and Robusta coffee for the analyzed period. Our findings revealed high H and L prices encourage growers to leave the sector for the most part of the analyzed period. High H and L prices resulted from high variable cost due to increasing wages for farm workers. The Ecuadorian government is developing a policy to help growers make production more efficient, encouraging them to remain in the sector in the long run.

NaCl protects against Cd and Cu-induced toxicity in the halophyte Atriplex halimus

  • Bankaji, Insaf
  • Sleimi, Noomene
  • Gómez-Cadenas, Aurelio
  • Pérez-Clemente, Rosa M.
The objective of the present work was to evaluate the extent of Cd- and Cu-induced oxidative stress and the antioxidant response triggered in the halophyte species Atriplex halimus after metallic trace elements exposure. Plants were treated for one month with Cd2+ or Cu2+ (400 µM) in the absence or presence of 200 mM NaCl in the irrigation solution. The interaction between salinity and heavy metal stress was analyzed in relation to plant growth, tissue ion contents (Na+, K+ and Mg2+), oxidative damage and antioxidative metabolism. Data indicate that shoot and root weight significantly decreased as a consequence of Cd2+- or Cu2+-induced stress. Metallic stress leads to unbalanced nutrient uptake by reducing the translocation of K+ and Mg2+ from the root to the shoot. The levels of malondialdehyde increased in root tissue when Cd, and especially Cu, were added to the irrigation solution, indicating that oxidative damage occurred. Results showed that NaCl gave a partial protection against Cd and Cu induced toxicity, although these contaminants had distinct influence on plant physiology. It can be concluded that salinity drastically modified heavy metal absorption and improved plant growth. Salinity also decreased oxidative damage, but differently in plants exposed to Cd or Cu stress.

In vitro effects of copper nanoparticles on plant pathogens, beneficial microbes and crop plants

  • Banik, Susanta
  • Pérez-de-Luque, Alejandro
Copper-based chemicals are effectively used as antimicrobials in agriculture. However, with respect to its nanoparticulate form there has been limited number of studies. In this investigation, in vitro tests on effect of copper nanoparticles (CuNPs) against plant pathogenic fungi, oomycete, bacteria, beneficial microbes Trichoderma harzianum and Rhizobium spp., and wheat seeds were conducted. Integration of CuNPs with non-nano copper like copper oxychloride (CoC) at 50 mg/L concentration each recorded 76% growth inhibition of the oomycete Phytophthora cinnamomi in vitro compared to the control. CuNPs also showed synergistic inhibitory effect with CoC on mycelial growth and sporulation of A. alternata. Pseudomonas syringae was inhibited at 200 mg/L of CuNPs. CuNPs were not significantly biocidal against Rhizobium spp. and Trichoderma harzianum compared to CoC. Evaluation of the effect of CuNP on wheat revealed that rate of germination of wheat seeds was higher in presence of CuNPs and CoC compared to control. Germination vigor index, root length, shoot dry weight and seed metabolic efficiency of wheat were negatively affected. At low concentration, CuNPs promoted the growth of the plant pathogenic fungi Botrytis fabae, Fusarium oxysporum f.sp. ciceris, F.oxysporum f.sp. melonis, Alternaria alternate and P. syringae, and sporulation of T. harzianum. Synergistic effect of CuNPs and CoC in inhibiting P. cinnamomi offers a possibility of developing new fungicide formulation for better control of the oomycetes. Non-biocidal effect of CuNPs against beneficial microbes indicates its potential use in the agri-ecosystem.

Segregation of soft olives using Durofel and on-line rebound, Separación de aceitunas blandas con Durofel y en línea empleando rebote

  • Barreiro, P.
  • Ruiz Altisent, M.
  • Moya, A.
  • Agulheiro, A.C.
  • Garcia Ramos, F.J.
Traditional table olive fermentation processing produces variable proportions of defective olives that must be eliminated before final packaging. Defects include fish eye ("alambradas"), compact ("compactas") and over-ripe olives. For two testing periods during the 2001 season, different batches were graded by size, colour parameters, hardness, density and rebound distance (total number tested was 760 olives). The latter was determined using a specially designed prototype made by an on-line rotating drum covered with a commercial rubber material to avoid damage (13.3 cm total diameter and 6.81 rad s-1 rotation speed). Results showed that 96% of measured variance could be explained by the four Principal Components Analysis of extracted factors. Moreover, hardness measured as Durofel- 25 units is closely related to rebound distance. Softness thresholds have been addressed for both hardness parameters with devoted logistic models, permitting correct segregation (with 95% of well-classified individuals) of all soft olives (over-ripe and fish eye) using the rebound drum., La fermentación tradicional de aceitunas de mesa da lugar a la aparición de distintos tipos de defectos, alambradas, compactas y sobremaduras, que hace que las aceitunas defectuosas deban eliminarse antes del empaquetado final. En este estudio, que abarca dos periodos de ensayo en 2001, se han evaluado varios lotes (760 aceitunas en total) que incluyen aceitunas sanas y defectuosas, caracterizándolas objetivamente por calibre, color, dureza, densidad y rebote. Este último parámetro se ha determinado mediante un dispositivo en línea consistente en un cilindro rotativo recubierto con un material amortiguador para evitar daños. Los resultados demuestran que el 96% de la varianza de los datos experimentales puede ser representada mediante cuatro factores principales, y que la firmeza determinada en unidades Durofel está altamente correlacionada con la distancia de rebote. Se han determinado los umbrales de rechazo de aceitunas para ambos parámetros de dureza mediante modelos logísticos, permitiendo separar correctamente de las sanas el 95% de las aceitunas blandas (alambradas y sobremaduras).

Dehydration kinetics of carrots (Daucus carota L.) in osmotic and air convective drying processes, Cinéticas de la deshidratación de zanahorias (Daucus carota L.) en procesos osmóticos y de secado convectivo con aire

  • Vázquez Vila, M.J.
  • Chenlo Romero, F.
  • Moreira Martínez, R.
  • Pacios Penelas, B.
This paper presents a kinetic study of osmotic dehydration and air drying with and without osmotic pre-treatment of carrot. Carrot cylinders of different diameters (4.5, 7 and 9 mm) were employed and, osmotic solutions of sodium chloride of different concentrations (17, 22 and 26% w/w) at various process temperatures (25, 35 and 45 deg C) and contact times (up to 180 min). The water loss (kg/kg) and the solid gain (kg/kg) in the samples increase with temperature and solution concentration increase. These parameters also depend on size (specific area) of the samples. The drying rate (kg water/kg dry solid/h) increases with temperature and decreases with the sample diameter. Experimental drying kinetics were fitted satisfactorily to a first order (simple model) kinetics (where the parameter ks ranges from 0.1748 up to 0.6691/h) and to the Page model [where the parameters kp (h-n) and n(-) range from 0.1592 and 1.0683 up to 0.6451 and 1.300, respectively] in order to determine the kinetic constants during drying. Osmotic dehydration combined with the air drying has proven to be an interesting method to reduce water in the samples without extreme thermal processes, nevertheless, the drying rate of the samples previously treated during 1 hour with osmotic dehydration decreased about 13%., En este trabajo se ha realizado un estudio cinético de la deshidratación osmótica y del secado con aire sin y con pretratamiento osmótico de la zanahoria. Se utilizaron cilindros de zanahoria de diferentes diámetros (4,5; 7 y 9 mm) y disoluciones osmóticas de cloruro sódico de distintas concentraciones (17, 22 y 26% en peso) a varias temperaturas de proceso (25, 35 y 45 grados C) y tiempos de contacto (hasta 180 min). La pérdida de agua (kg/kg) y la ganancia de sólidos (kg/kg) en las muestras aumentaron con la temperatura y la concentración de la disolución. Estos parámetros también dependieron del tamaño (área específica) de las muestras. La velocidad de secado (kg/kg de sólido seco/h) aumentó con la temperatura y disminuyó con el diámetro de muestra. Se ajustaron los datos experimentales satisfactoriamente a una cinética de primer orden, modelo simple (donde el parámetro ks varía desde 0,1748 hasta 0,6691/h) y al modelo de Page (donde el parámetro kp (h-n) y n(-) varían desde 0,1592 y 1,0683 hasta 0,6451 y 1,300, respectivamente) para determinar las constantes cinéticas durante el secado. La deshidratación osmótica combinada con el secado con aire resulta ser un método interesante para reducir el agua de las muestras sin procesos térmicos extremos, sin embargo, la velocidad de secado de las muestras previamente tratadas con 1 hora de deshidratación osmótica disminuye en torno a un 13%.

Performance, carcass and ruminal fermentation characteristics of heifers fed concentrates differing in energy level and cereal type (corn vs. wheat)

  • Carrasco, Coral
  • Carro, María D.
  • Fuentetaja, Alfonso
  • Medel, Pedro
A total of 144 beef heifers (218 ± 26.4 kg body weight) were housed in 24 pens (6 animals each) and used in a 168-day feedlot study to evaluate the influence of cereal type and energy level on performance, carcass quality and ruminal fermentation. Four concentrates were formulated according to a 2×2 factorial arrangement of treatments, with two energy levels (1,452 vs. 1,700 kcal net energy/kg) and two main cereals (wheat vs. corn). Concentrate and straw were offered ad libitum. Concentrate intake and body weight were recorded on days 42, 84, 126 and 168. Ruminal fluid was obtained by ruminocentesis from 3 heifers per pen on days 1, 84 and 168; and carcass weight, classification and yield, were determined in the same animals. Heifers fed high-energy diets had lower intake (6.97 vs. 7.29 kg fresh matter/d; p=0.011), and lower concentrate to gain ratio (5.15 vs. 5.66 kg/kg; p=0.002) than those fed low energy concentrates, and tended (p=0.069) to be heavier along the time. Neither carcass yield and classification, nor ruminal pH, volatile fatty acids nor NH3-N concentrations were affected (p>0.050) by energy level. Total volatile fatty acids concentration tended (p=0.070) to be greater in heifers fed corn-based than wheat-based concentrates. No energy level x cereal type interactions were observed. These results indicate that high energy concentrates decreased feed intake and feed conversion but had minor effects on carcass performance. Cereal type had no effects on performance and ruminal fermentation and no interactions between cereal type and energy were detected.

The effects of melatonin on in vitro oocyte competence and embryo development in sheep, Efecto de la melatonina en la competencia del oocito y el desarrollo embrionario ovino in vitro

  • Casao, A.
  • Abecia, J.A.
  • Cebrián Pérez, J.A.
  • Muiño Blanco, T.
  • Vázquez, M.I.
  • Forcada, F.
The aim of this study was to assess the effects of melatonin on the in vitro maturation and fertilization of sheep oocytes, and on the in vitro culture of the embryos. Oocytes from sheep ovaries collected at the slaughterhouse were divided into four groups, two of which were treated with either 10E–5 M (M5) or 10E–6 M (M6) melatonin, while the other two groups served as untreated controls (C5 and C6). After in vitro fertilization with fresh ram semen, the embryos produced in each group were divided into two sets, one cultured with melatonin (M5M, C5M, M6M and C6M), and the other without melatonin (M5C, C5C, M6C, and C6C). A melatonin concentration of 10E–6 M increased maturation rate (82.5% vs. 73.7% for M6 and C6, respectively; P < 0.05) and tended to improve cleavage rate 36 hours after in vitro fertilization (79.4% vs. 72.6% for M6 and C6, respectively, P = 0.08). A higher melatonin concentration (10E–5 M) did not have significant effects on those parameters. Blastocyst rates on day 8 did not differ significantly among groups., El objetivo de este estudio es determinar el efecto de la melatonina sobre la maduración y fecundación in vitro de ovocitos ovinos, y sobre el cultivo in vitro de los embriones obtenidos. Ovocitos extraídos de ovarios de ovejas obtenidos en matadero se dividieron en cuatro grupos, de los cuales dos fueron tratados con melatonina 10E–5 M (M5) ó 10E–6 M (M6), mientras que los otros dos sirvieron como grupos control (C5 y C6). Tras su fecundación in vitro con semen fresco de morueco, los embriones obtenidos en cada grupo se dividieron a su vez en otros dos grupos, de forma que la mitad se cultivaron con melatonina (M5M, C5M, M6M y C6M), y la otra mitad sin ella (M5C, C5C, M6C, y C6C). La concentración 10E–6 M de melatonina aumentó el porcentaje de maduración de los ovocitos (82,5% vs. 73,7% en los grupos M6 y C6, respectivamente; P < 0,05) y tendió a mejorar el porcentaje de embriones divididos 36 horas tras la fecundación (79,4% vs. 72,6% en los grupos M6 y C6, respectivamente; P = 0,08). Una mayor concentración de melatonina (10E–5 M) no tuvo efecto significativo sobre estos parámetros. No se encontraron diferencias significativas en los porcentajes de blastocistos tras ocho días de cultivo.

Comparison of an antioxidant system in tolerant and susceptible wheat seedlings in response to salt stress

  • Feki, Kaouthar
  • Tounsi, Sana
  • Brini, Faiçal
It has been demonstrated previously that the physiological and molecular analysis of seedlings of the tolerant (Om Rabia3) and susceptible (Mahmoudi) Tunisian wheat genotypes were different at short and long-term response to salinity. In this study, we examined the antioxidant defence system in seedlings of these two cultivars at short-term response to different NaCl concentrations. The findings showed that high salinity tolerance of cv. Om Rabia3, as manifested by lower decrease in its dry biomass, was associated with lower malondialdehyde and hydrogen peroxide contents, lower accumulation of the superoxide (O2⎯) in the roots and the shoots, and also lower decrease in ascorbate content than those in cv. Mahmoudi. Moreover, the expression of some genes coding for antioxidant enzymes such as the catalase, the superoxide dismutase and the peroxidase were enhanced by NaCl stress especially in the salt-tolerant cultivar. In parallel, their activities were  increased in response to the same condition of stress and especially in the cv. Om Rabia3. Taken together, these data suggested that the capacity to limit oxidative damage is important for NaCl tolerance of durum wheat.

Effect of DPA [Diphenylamine] and 1-MCP [1-methylcyclopropene] on chemical compounds related to superficial scald of Granny Smith apples, Efecto de la aplicación de DPA [Difenilamina] y 1-MCP 1-metilciclopropeno] sobre compuestos químicos relacionados con el desarrollo de escaldado superficial de manzanas Granny Smith

  • Moggia, C.
  • Moya-León, M.A.
  • Pereira, M.
  • Yuri, J.A.
  • Lobos, G.A.
Research was carried out to study the mode of action of diphenylamine (DPA) and 1-methylcyclopropene (1-MCP), on control of superficial scald of Granny Smith apples (Malus domestica Borkh.), and its relation with chemical compounds. Fruit was harvested from a commercial orchard in Chile, 182 and 189 days after full bloom and received the following treatments: DPA (2,000 ppm); 1-MCP (1.2 ppm) and control (no treatment). All fruit was stored for 4 or 6 months at 0 deg C. A completely randomized factorial design was used (2 harvest dates by 3 postharvest treatments). Monthly measurements were made on maturity indices, ethylene production rate (EPR), scald related compounds (alpha-farnesene (AF), conjugated trienes (CT), total anti-oxidants (AO)), and cell membrane stability. Following 4 and 6 months of storage, plus 7 days at 20 deg C, scald was evaluated. After 6 months, DPA-treated fruit, from both harvests, showed similar firmness, EPR and AO, compared to the control. However, AF and CT were lower, and cell membrane stability higher. Conversely, 1-MCP-treated fruit showed a noticeable EPR suppression and AF inhibition, along with higher firmness, lower CT and AO, compared to the control and DPA. Furthermore, cell membrane stability was superior to that of the control and similar to that of the DPA. Treated fruit (DPA and 1-MCP) showed an important reduction in scald compared to the control. The effect of 1-MCP on the investigated compounds and the reduction in scald, confirms that ethylene plays a major role on its development., Se realizó una investigación para estudiar el modo de acción de difenilamina (DPA) y 1-metilciclopropeno (1-MCP) en el control de escaldado superficial de manzanas (Malus domestica Borkh.) Granny Smith y su relación con compuestos químicos. La fruta fue cosechada de un huerto comercial en Chile, 182 y 189 días después de plena flor y recibió los siguientes tratamientos: DPA (200 ppm), 1-MCP (1,2 ppm) y control (sin tratamiento). Toda la fruta fue almacenada de 4 a 6 meses a 0 grados C. Se utilizó un diseño factorial completamente al azar (2 fechas de cosecha x 3 tratamientos postcosecha). Mensualmente se realizaron mediciones de índices de madurez, tasa de producción de etileno (EPR), compuestos relacionados con el escaldado (alfa-farneseno (AF), trienos conjugados (CT), antioxidantes totales (AO)) y estabilidad de la membrana celular. El escaldado fue evaluado después de 4 y 6 meses de almacenaje, más 7 días a 20 grados C. Después de 6 meses, la fruta tratada con DPA, de ambas cosechas, mostró similar firmeza, EPR y AO en comparación al control. Sin embargo, AF y CT fueron menores y la estabilidad de la membrana celular mayor. Por otra parte, la fruta tratada con 1-MCP mostró una notable supresión de EPR e inhibición de AF, junto a una mayor firmeza, menor CT y AO, en comparación con el control y el tratamiento con DPA. Adicionalmente, la estabilidad de la membrana celular fue superior a la del control y similar a la de DPA. La fruta tratada (DPA y 1-MCP) mostró un desarrollo del escaldado reducido comparado con el control. El efecto de 1-MCP en los compuestos investigados y en la reducción del desorden confirma el papel preponderante del etileno en su desarrollo.

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