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11.
Alon Ben-Gal Nurit Agam Victor Alchanatis Yafit Cohen Uri Yermiyahu Isaac Zipori Eugene Presnov Michael Sprintsin Arnon Dag 《Irrigation Science》2009,27(5):367-376
Irrigation of olive orchards is challenged to optimize both yields and oil quality. Best management practices for olive irrigation
will likely depend on the ability to maintain mild to moderate levels of water stress during at least some parts of the growing
season. We examined a number of soil, plant and remote sensing parameters for evaluating water stress in bearing olive (var.
Barnea) trees in Israel. The trees were irrigated with five water application treatments (30, 50, 75, 100 and 125% of potential
evapotranspiration) and the measurements of soil water content and potential, mid-day stem water potential, and stomatal resistance
were taken. Remote thermal images of individual trees were used to alternatively measure average canopy temperature and to
calculate the tree’s crop water stress index (CWSI), testing empirical and analytical approaches. A strong non-linear response
showing similar trends and behavior was evident in soil and plant water status measurements as well as in the CWSI, with decreasing
rates of change at the higher irrigation application levels. No statistically significant difference was found between the
analytical and the empirical CWSI, suggesting that the relative simplicity of the analytical method would make it preferable
in practical applications. 相似文献
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Ben-Gal A Dag A Basheer L Yermiyahu U Zipori I Kerem Z 《Journal of agricultural and food chemistry》2011,59(21):11667-11675
Five rates of water application were applied in a 4 year study on olive (Olea europaea) varieties 'Barnea' and 'Souri'. Increased irrigation lead to increased tree-scale oil yields, lower polyphenol content, and, frequently, higher oil acidity. These effects were predominant in "off" years. The fatty acid profile was influenced primarily by bearing level and variety and secondarily by irrigation rate. The saturated to unsaturated fatty acid ratio was higher in "off" than in "on" years, and the monounsaturated fatty acid to polyunsaturated fatty acid ratio was higher in "on" years as a result of the fact that oleic and stearic acids were higher in "on" years, while palmitic, palmitoleic, and linoleic acids were greater in "off" years. Squalene was higher in 'Souri' than in 'Barnea' oils, was not affected by bearing cycle, and was consistently lower in oil from trees receiving the lowest irrigation level. 相似文献
14.
Nurit Agam Eran Segal Aviva Peeters Asher Levi Arnon Dag Uri Yermiyahu Alon Ben-Gal 《Precision Agriculture》2014,15(3):346-359
Information regarding tree water status in irrigated olive orchards is essential for managing growth to optimize yields and olive oil quality. One management practice option is to monitor or sample individual trees and use this information for orchard-scale management. This study assessed the ability of thermal imaging to provide the spatial distribution and variability of tree water status in a commercial irrigated olive orchard, and described strategies and a procedure for choosing which individual trees best represent the orchard. The study employed gradual upscaling from individual trees grown in lysimeters, through a controlled experimental field plot, to a commercial orchard. Thermal imaging of olive trees grown in lysimeters attested the sensitivity of the technique to identify mild-level water stress by correlating crown temperatures to stem water potential. Knowledgeable choice of five or ten representative trees in the experimental plot, based on the histogram distribution obtained for the entire experimental orchard, lead to successful reconstruction of the spatial distribution of canopy temperature, and thus of water status. Positively skewed distributions of crown temperatures found in both the field plot and commercial orchard suggested distinct patterns, where the canopy temperature of the majority of the trees was lower than the average, and a relatively small number of trees had significantly higher temperatures and suggest commercial practicality of the proposed methodology. Thermal imaging can therefore serve as a useful tool for determining representative trees that, if frequently monitored, or instrumented with continuous water status sensors, can provide important information for orchard water management. 相似文献
15.
Katz L. Ben-Gal A. Litaor M. I. Naor A. Peres M. Bahat I. Netzer Y. Peeters A. Alchanatis V. Cohen Y. 《Precision Agriculture》2022,23(4):1125-1152
Precision Agriculture - Wide assimilation of precision agriculture among farmers is currently dependent on the ability to demonstrate its efficiency at the field-scale. Yet, most experiments that... 相似文献