58 research outputs found
Factors that Affect the Quality of Olive Oil Produced Using Olives from Traditional Orchards in the Middle East
Traditional olive (Olea europaea) orchards have been grown for thousands of years and still occupy most of the world’s cultivated olive areas. To compete with olive oil produced in the higher-yielding intensive orchards, the oil from traditional orchards must be of high quality. We evaluated oil quality—potential and actual (under commercial conditions)—and tested the stages in the production chain that are likely to reduce oil quality in the traditional sector in the Middle East region. Our findings show a clear negative impact of growers’ traditional practices on both the chemical and sensory characteristics of olive oil. The oil originating from the commercial process had higher free fatty acid and lower polyphenol and carotenoid contents, lower stability, lower pungency, lower fruitiness, lower bitterness, and a higher prevalence of organoleptic defects than oil that originated from fruit picked from the same trees during the experimental procedure. The current common harvesting technique of pole beating significantly increased fruit injury and fruit with mold, leading to a reduction in oil polyphenols and an increase in free fatty acid levels compared with those resulting from manual picking. In addition, after harvest, storing the fruit for more than 48 hours in plastic bags dramatically reduced the oil quality. The traditional olive orchard could be a source of high-quality extra virgin olive oil. However, fruit handling—from the trees until the end of the oil extraction process—is performed incorrectly, thus adversely affecting the oil quality
Effects of Olive Mill Wastewater on Soil Microarthropods and Soil Chemistry in Two Different Cultivation Scenarios in Israel and Palestinian Territories
Although olive mill wastewater (OMW) is often applied onto soil and is known
to be phytotoxic, its impact on soil fauna is still unknown. The objective of this study was
to investigate how OMW spreading in olive orchards affects Oribatida and Collembola
communities, physicochemical soil properties and their interdependency. For this, we
treated plots in two study sites (Gilat, Bait Reema) with OMW. Among others, the sites
differed in irrigation practice, soil type and climate. We observed that soil acidity and
water repellency developed to a lower extent in Gilat than in Bait Reema. This may be
explained by irrigation-induced dilution and leaching of OMW compounds in Gilat. In Bait
Reema, OMW application suppressed emergence of Oribatida and induced a community
shift, but the abundance of Collembola increased in OMW and water-treated plots. In
Gilat, Oribatida abundance increased after OMW application. The effects of OMW
application on soil biota result from an interaction between stimulation of biological activity and suppression of sensitive species by toxic compounds. Environmental and
management conditions are relevant for the degree and persistence of the effects.
Moreover, this study underlines the need for detailed research on the ecotoxicological
effects of OMW at different application rates
Standard methods for pollination research with Apis mellifera
Fil: Delaplane, Keith S. University of Georgia. Department of Entomology; USA.Fil: Dag, Arnon. Ministry of Agriculture. Agricultural Research Organization. Gilat Research Center; Israel.Fil: Danka, Robert G. Honey Bee Breeding, Genetics, and Physiology Research; USA.Fil: Freitas, Breno M. Universidade Federal do Ceará. Departamento de Zootecnia - CCA; Brazil.Fil: Garibaldi, Lucas Alejandro. Universidad Nacional de RĂo Negro. Sede Andina; Argentina.Fil: Goodwin, Mark R. Plant and Food Research. The New Zealand Institute for Plant and Food Research Limited; New Zealand.Fil: Hormaza, JosĂ© I. Instituto de Hortofruticultura Subtropical y Mediterranea La Mayora (IHSM La Mayora-CSIC-UMA); Spain.Fil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina.In this chapter we present a synthesis of recommendations for conducting field experiments with honey bees in the context of agricultural pollination. We begin with an overview of methods for determining the mating system requirements of plants and the efficacy of specific pollinators. We describe methods for evaluating the pollen vectoring capacity of bees at the level of individuals or colonies and follow with methods for determining optimum colony field stocking densities. We include sections for determining post harvest effects of pollination, the effects of colony management (including glasshouse enclosure) on bee pollination performance, and a brief section on considerations about pesticides and their impact on pollinator performance. A final section gives guidance on determining the economic valuation of honey bee colony inputs at the scale of the farm or region
Standard methods for pollination research with Apis mellifera 2.0
In this chapter we present a synthesis of recommendations for conducting field experiments with honey bees in the context of agricultural pollination. We begin with an overview of methods for determining the mating system requirements of plants and the efficacy of specific pollinators. We describe methods for evaluating the pollen-vectoring capacity of bees at the level of individuals or colonies and follow with methods for determining optimum colony field stocking densities. We include sections for determining post-harvest effects of pollination, the effects of colony management (including glasshouse enclosure) on bee pollination performance, and a brief section on considerations about pesticides and their impact on pollinator performance. A final section gives guidance on determining the economic valuation of honey bee colony inputs at the scale of the farm or region.Fil: Sagili, Ramesh Reddy. State University of Oregon; Estados UnidosFil: Chakrabarti, Priyadarshini. Mississippi State University.; Estados UnidosFil: Melathopoulos, Andony. State University of Oregon; Estados UnidosFil: Delaplane, Keith S.. University of Georgia; Estados UnidosFil: Dag, Arnon. Ministry Of Agriculture; IsraelFil: Danka, Robert G.. Horticultural Research Laboratory ; United States Department Of Agriculture;Fil: Freitas, Breno M.. Universidade Federal Do Ceara; BrasilFil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones En Recursos Naturales, Agroecologia y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones En Recursos Naturales, Agroecologia y Desarrollo Rural.; ArgentinaFil: Hormaza, Jose I.. Consejo Superior de Investigaciones CientĂficas; EspañaFil: Steinhauer, Nathalie. State University of Oregon; Estados Unido
Fruit load governs transpiration of olive trees
We tested the hypothesis that whole-tree water consumption of olives (Olea europaea L.) is fruit load-dependent and investigated the driving physiological mechanisms. Fruit load was manipulated in mature olives grown in weighing-drainage lysimeters. Fruit was thinned or entirely removed from trees at three separate stages of growth: early, mid and late in the season. Tree-scale transpiration, calculated from lysimeter water balance, was found to be a function of fruit load, canopy size and weather conditions. Fruit removal caused an immediate decline in water consumption, measured as whole-plant transpiration normalized to tree size, which persisted until the end of the season. The later the execution of fruit removal, the greater was the response. The amount of water transpired by a fruit-loaded tree was found to be roughly 30% greater than that of an equivalent low- or nonyielding tree. The tree-scale response to fruit was reflected in stem water potential but was not mirrored in leaf-scale physiological measurements of stomatal conductance or photosynthesis. Trees with low or no fruit load had higher vegetative growth rates. However, no significant difference was observed in the overall aboveground dry biomass among groups, when fruit was included. This case, where carbon sources and sinks were both not limiting, suggests that the role of fruit on water consumption involves signaling and alterations in hydraulic properties of vascular tissues and tree organs.</p
The effect of avocado ( Persea americana
International audienc
Omega-6:3 Ratio More Than Absolute Lipid Level in Diet Affects Associative Learning in Honey Bees
Floral pollen is a major source of honey bee nutrition that provides them with micro- and macro-nutrients, including proteins, fatty acids, vitamins, and minerals. Different pollens vary in composition, including in the essential fatty acids, alpha-linolenic acid (omega-3) and linoleic acid (omega-6). Monocultures, prevalent in modern agriculture, may expose honey bee colonies to unbalanced omega-6:3 diets. The importance of omega-3 in the diet for adequate learning and cognitive function, with a focus on suitable omega-6:3 ratio, is well documented in mammals. We have recently shown, for the first time in invertebrates, the importance of omega-3 in diets for associative learning ability in honey bees. In the current work, we examine the effect of the absolute amount of omega-3 in diet compared to the omega-6:3 ratio on honey bee associative learning. We fed newly emerged bees for 1 week on different artificial diets, which had lipid concentration of 1, 2, 4, or 8%, with omega-6:3 ratios of 0.3, 1, or 5, respectively. We then tested the bees in a proboscis-extension response olfactory conditioning assay. We found that both omega-6:3 ratio and total lipid concentration affected learning. The most detrimental diet for learning was that with a high omega-6:3 ratio of 5, regardless of the absolute amount of omega-3 in the diet. Bees fed an omega-6:3 ratio of 1, with 4% total lipid concentration achieved the best performance. Our results with honey bees are consistent with those found in mammals. Best cognitive performance is achieved by a diet that is sufficiently rich in essential fatty acids, but as long as the omega-6:3 ratio is not high
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