Photosynthetic rates of both C(4)- and C(3)-pathway plants grown at 25 C were measured before and during a period of chilling stress at 10 C, and then again at 25 C following various periods at 10 C. When temperatures are first lowered photosynthetic rates drop immediately, then undergo a further reduction which is quite rapid in species such as Sorghum, maize, and Pennisetum; slower in soybean...

Greenhouses with sophisticated environmental control systems, or so-called plant factories with solar light, enable growers to achieve high yields of produce with desirable qualities. In a greenhouse crop with high planting density, low photosynthetic photon flux density (PPFD) at the lower leaves tends to limit plant growth, especially in the winter when the solar altitude and PPFD at the cano...

In this paper, we evaluate the potential for extracting the “photochemical reflectance index” (PRI; previously called the “physiological reflectance index”) from AVIRIS data. This index, which is derived from narrow-band reflectanceat531 and 570 nm, has proven to be a useful indicator of photosynthetic function at the leaf and canopy scales (Gamon and Field 1992, Gamon et al. 1992, Pcfiuelas et...

BACKGROUND Soil water and nitrogen (N) are considered to be the main environmental factors limiting plant growth and photosynthetic capacity. However, less is known about the interactive effects of soil water and N on tree growth and photosynthetic response in the temperate ecosystem. METHODS/PRINCIPAL FINDINGS We applied N and water, alone and in combination, and investigated the combined ef...

The sexes of dioecious species may differ in a range of vegetative and reproductive traits as well as in physiological traits. In Siparuna grandiflora, a Neotropical dioecious shrub, we examined differences in leaf-level photosynthesis of different classes of leaf age and, using simulation models, explored whether differences in leaf-level carbon gain led to sex differences in whole-plant daily...

Eucryphia cordifolia Cav. is a long-lived evergreen tree species, commonly found as a canopy emergent tree in the Chilean temperate rain forest. This species displays successive leaf cohorts throughout the entire growing season. Thus, full leaf expansion occurs under different environmental conditions during growing such as air temperature, vapor pressure deficit and the progress of moderate wa...

A biotic stresses can directly or indirectly affect the physiological status of an organism by altering its metabolism, growth, and development. In order to study the effect of drought stress on Citrullus colocynthis samples a factorial experiment was conducted in Horticultural science Department of University of Tehran in 2013. The first factor was two accessions of Citrullus colocynthis (Yazd...

Leaf longevity (LL) varies more than 20-fold in tropical evergreen forests, but it remains unclear how to capture these variations using predictive models. Current theories of LL that are based on carbon optimisation principles are challenging to quantitatively assess because of uncertainty across species in the 'ageing rate:' the rate at which leaf photosynthetic capacity declines with age. He...