Diseño y manejo del olivar en seto: efecto en la producción y calidad del aceite

El olivar en seto adaptado a la recolección con vendimiadora modificada, supone una alternativa viable a los olivares preparados para la recolección con vibrador de tronco. Presenta como principales ventajas: altas producciones en los primeros años, bajo coste de recolección, menor mano de obra y recolección rápida en el momento óptimo. Sin embargo, estas características sólo son posibles con estructuras óptimas, mantenidas en el tiempo. La intercepción de la radiación solar es el factor determinante de la producción de aceite, así la estructura óptima del seto deberá tender a maximizar la iluminación de la copa. Debido a que el olivar en seto es de reciente implantación, se desconoce la respuesta de la producción y calidad de aceite en setos de diferentes tamaños en distintas localidades. Las simulaciones de producción y calidad de aceite para distintos diseños serán útiles para el sector a la hora de decidir la estructura óptima. En este artículo describimos los avances realizados en este sentido y los retos que, agricultores e investigadores, deberemos ir resolviendo

Products of Nearly Holomorphic Eigenforms

We prove that the product of two nearly holomorphic Hecke eigenforms is again a Hecke eigenform for only finitely many choices of factors.Comment: 8 page

Atrazine and cancer incidence among pesticide applicators in the agricultural health study (1994-2007).

Atrazine is a triazine herbicide used widely in the United States. Although it is an animal carcinogen, the mechanism in rodents does not appear to operate in humans. Few epidemiologic studies have provided evidence for an association

An Environmental and Climate History of the Roman Expansion in Italy

A first synthesis of available data for the period of Rome’s expansion in Italy (about 400–29 b.c.e.) shows the role of climate and environment in early Roman imperialism. Although global indices suggest a warmer phase with relatively few short-term climate events occuring around the same time as the expansion, local data emphasize the highly variable timing and expression of these trends. This variability casts doubt on ideas of a unitary, historically consequential “Roman Warm Period.” The historical importance of climate and environment to socioeconomic development merits emphasis, but should be understood in terms of evolving, contingent forms of resilience and risk-mitigating behavior by Italian communities during Roman expansion

Modelling the intraspecific variation in the dynamics of fruit growth, oil and water concentration in olive (Olea europaea L.)

Olive oil yield is the product of fruit weight and oil concentration at maturity; knowledge of the dynamics and allometric relationships of these components could help understanding the genotypic, environmental and management sources of variation in oil yield.The aims of this work were to: model the dynamics of fruit weight, oil and water concentration in olive varieties; quantify the relationship between the dynamics of fruit component in terms of rate and duration and their responses to environmental factors and explore the relationship between oil yield components using an allometric approach. Ten olive varieties were monitored during two seasons in Mendoza (32°S), Argentina. The evolution of fruit weight and concentration of oil and water (from pit hardening to maturity were fitted with bilinear functions and the parameters derived (maximum, rate, onset and duration) were associated with weather variables. Across seasons, fruit fresh weight (wt) (range from 252 to 749mg), fruit wt-filling rate (0.1-0.3mg°Cd -1) and fruit wt-filling duration (2288-2913°Cd) exhibited significant genotypic variation. The fruit wt-filling rate accounted for 91% of the variation in fruit fresh wt. Fruit fresh wt and fruit wt-filling rate varied between seasons while no significant differences were found for fruit wt-filling duration. Fruit oil concentration (45.5-57.4%) and duration (2425-2876°Cd) varied among varieties, but was largely unaffected by season. Oil-filling duration was the most important term in determining the fruit oil concentration (P=0.0013). During fruit growth, fruit water concentration remained stable at its maximum and declined linearly when fruit reached maximum fresh weight and oil concentration. Fruit oil concentration decreased with increasing maximum daily temperature (P=0.04) and solar radiation (P=0.01). © 2012 Elsevier B.V.Eduardo R. Trentacoste, Carlos M. Puertas, Víctor O. Sadra

Leaf Biochemical and Kernel Metabolite Profiles as Potential Biomarkers of Water Deficit in Walnut (<i>Juglans regia</i> L.) cv. Chandler

Walnut cultivation is expanding into regions where water availability for irrigation is lower than crop evapotranspiration. However, information regarding the responses and adaptations of walnut trees to water deficit remains scarce. In this study, we applied three irrigation levels, 100%, 75%, and 50% of crop evapotranspiration (referred to as T100, T75, and T50, respectively), to Chandler walnut trees over two consecutive seasons. During the second season, we evaluated leaf water-deficit biomarkers, including proline, malondialdehyde, soluble sugars, phenols, and flavonoids, using targeted spectrophotometry. Despite not finding significant differences in biomarker concentrations among the irrigation regimes, we observed variations between different collection times (sprouting, endocarp hardening, and maturity). Furthermore, we assessed the kernel metabolome using untargeted gas chromatography–mass spectrometry, profiling seventy-one metabolites across all samples. Notably, forty-one of these metabolites were identified as members of distinct groups, comprising carbohydrates (n = 11), fatty acids (n = 11), organic acids (n = 9), and amino acids (n = 5). Linear mixed models showed no significant differences between the irrigation regimes. However, in the T50 treatment, multivariate analysis (PCA) revealed a higher concentration of osmotic adjustment metabolites, which are potentially associated with protecting oil biosynthesis under high-temperature and water deficit conditions