to evaluate the effect of different levels of drought stress on some physiological parameters in strawberry, potted experiment involing strawberry cultivars  ‘marak٫ , ‘camarosa٫ and ‘gaviota٫ was conducted during summer 2009. the experiment consisted of three drought stress levels in three replications. the experimental arrangement was a factorial one, based upon a randomized complete block de...

Partial rootzone drying (PRD) is a new irrigation technique which improves the water use efficiency (by up to 50%) of wine grape production without significant crop reduction. The technique was developed on the basis of knowledge of the mechanisms controlling transpiration and requires that approximately half of the root system is always maintained in a dry or drying state while the remainder o...

Oxalic acid is a virulence factor of several phytopathogenic fungi, including Sclerotinia sclerotiorum (Lib.) de Bary, but the detailed mechanisms by which oxalic acid affects host cells and tissues are not understood. We tested the hypothesis that oxalate induces foliar wilting during fungal infection by manipulating guard cells. Unlike uninfected leaves, stomatal pores of Vicia faba leaves in...

Preliminary results of simulation by the RATP (Radiation Absorption, Transpiration and Photosynthesis) model on olive tree are presented. At leaf level, Jarvis ́ stomatal conductance (gs) model and Faquhar ́s photosynthesis (A) model were parameterised on 2-year-old plants under controlled conditions. At canopy level the spatial distribution of leaf area density of a 31-year-old tree was describe...

The objective of this study was to compare stem flow and porometer methods of measuring transpiration of honey mesquite (Prosopis glandulosa) trees on a semiarid site. Stem flow was measured using heat balance stem flow gauges. Porometer measurements of leaf stomatal conductance (gs) were made within foliage layers of each stem and scaled to transpiration values for the entire stem (Estern) usi...

transpiration of a boreal forest: the branch bag, sap flow and eddy covariance methods. The branch bag method encloses several thousand needles and gives a continuous record of branch transpiration. The sap flow method provides a continuous record of sap velocity and an estimate of tree transpiration. The eddy covariance method typically measures evaporation rates between a forest and the atmos...