Photosynthesis was studied in sunflower plants subjected to 1 to 2 days of desiccation and then permitted to recover. The leaf water potential to which leaves returned after rewatering was dependent on the severity of desiccation and the evaporative conditions. Under moderately evaporative conditions, leaf water potential returned to predesiccation levels after 3 to 5 hours when desiccation was...

to evaluate morphological markers linked with drought stress resistance for screening almond genotypes in the breeding programs the effect of drought stress was studied on six nominated almond genotypes seedlings. the six pre-selected water stress mimposed almond genotypes included: homozygote sweet (butte from university of california), heterozygote sweet (shahrood12, shahrood18, shahrood21 an...

Different approaches have been used to simulate leaf area index (LAI) in soybean (Glycine max L. Merr). Many of these approaches require genotype-specific calibration procedures. Studies modeling LAI dynamics under optimal growth conditions with yields close to the yield potential of soybean have remained scarce. A sink-driven approach was developed and evaluated for LAI simulation in soybean u...

Declining net primary production (NPP) with forest age is often attributed to a corresponding decline in gross primary production (GPP). We tested two hypotheses explaining the decline of GPP in ageing stands (14-115 years old) of Pinus taeda L.: (1) increasing N limitation limits photosynthetic capacity and thus decreases GPP with increasing age; and (2) hydraulic limitations increasingly indu...

an experiment was conducted to determine the effect of paclobutrazol (pbz) and different irrigation amount on growth of aerial parts, leaf minerals and root performance in young olive plants cv. ‘manzanillo’ in the department of horticulture, faculty of agriculture, tarbiat modarres university in 2000. a split plot experiment in time was used based on a completely randomized block design with f...

safflower oil seed has high adaptability to different kinds of abiotic stresses such as drought and salinity. the aim of this study was to evaluate the effects of drought stress at different phenological stages on relative water content (rwc), leaf canopy temperature, seed yield and its components in spring types of safflower. the study was carried out in east azarbaijan research center for agr...

abstract the grasses cold tolerance is the most important limiting factor for its cultivation in temperate regions, so using cold tolerant cultivars is essential for grasses successful cultivation. in order to evaluation freezing stress tolerance of several species of grasses, this study was conducted in agricultural faculty of ferdowsi university of mashhad as a factorial complete randomized b...

abstract low water holding capacity of soilless substrates increases water stress and waste of nutrient solution. irrigation time management can reduce such problems. in this research, responses of hydroponically cultured greenhouse strawberries were evaluated under different irrigation schedules. in first step, plant daily water need was estimated and then delivered to plants through two metho...

This study was conducted to evaluate the response of Iranian promisinglate blooming almond genotypes to deficit-irrigation stress on GN15 rootstock. One-year old plants subjectedto three deficit-irrigation, including moderate and severe stress (soil water potential, Ψsoil = -0.8 and -1.6 MPa, respectively) and a control treatment (Ψsoil= -0.33 MPa), were applied for six weeks to five grafting c...

changes during shrinkage, aquaporin activity and/or changes in the vapor phase transport. The application of models calibrated with anatomy will be an essential approach to determining the drivers of K ox decline. Finally, speculation that K ox decline may protect the xylem in the leaf and throughout the rest of the plant from tensions that induce embolism needs to be validated using models and...