Attached apple leaves (Pyrus malus L., Golden Delicious) began to lose protein in early August as the first sign of senescence. Apple leaf discs prepared from samples before early August gained protein for up to 7 days after detachment. After early August, the loss of protein from leaf discs was no greater than the loss from attached leaves in 7 days. The loss of chlorophyll from leaf discs beg...

Spatial and temporal variations in canopy structure and leaf biochemistry have considerable influence on fluxes of CO2, water and energy and nutrient cycling in vegetation. Two vegetation indices (VI), NDVI and Macc01, were used to model the spatio-temporal variability of broadleaf chlorophyll content and leaf area index (LAI) across a growing season. Ground data including LAI, hyperspectral le...

Most of the previous studies on functional traits focus exclusively on either seedlings or trees. Little knowledge exists on the relationships between community level functional traits of trees and seedlings during succession. Here, we examine variations of the community-level functional traits for trees and seedlings and their correlations along a secondary successional and environmental gradi...

The quantum yield of photosystem II, determined by chlorophyll fluorescence and the quantum yield of CO2 uptake, determined from gas exchange, are two physiologically important measurements in clarifying the response to environmental stress. Both measurements, however, require an accurate assessment of leaf light absorption in the photosynthetically active radiation wavelength range (400–700 nm...

Hormones which inhibit senescence in Rumex leaf tissue in the dark include gibberellic acid and the cytokinin zeatin. Abscisic acid accelerates senescence in this tissue. Other workers have proposed that cytokinins, but not gibberellins, interact with abscisic acid in senescing Rumex leaf tissue. The present study reinvestigates the question of interaction using measurements of chlorophyll degr...

We investigated for 2 years (1995–1996) the time course development of chlorosis and the variation of iron (Fe) content in vegetative and reproductive organs in two nectarine orchards planted with cv Spring Red and cv Stark Redgold on calcareous soils of the Po valley (Italy) with the final aim to evaluate possible tools for the early prognosis of Fe chlorosis and a more efficient fertilization...

The effects of high Zn concentration were investigated in sugar beet (Beta vulgaris L.) plants grown in a controlled environment in hydroponics. High concentrations of Zn sulphate in the nutrient solution (50, 100 and 300 microm) decreased root and shoot fresh and dry mass, and increased root/shoot ratios, when compared to control conditions (1.2 microm Zn). Plants grown with excess Zn had inwa...

this study was conducted under ahvaz, iran environmental condition during 2012 and 2013 growing seasons in order to investigate the influence of foliar application of potassium on some physiological and biochemical characteristics of three olive cultivars including ‘mission’, ‘koroneiki’ and ‘dezfuli’. potassium sulfate in different concentrations of 0, 1, and 2 g l-1 was sprayed twice on selec...

One of the main factors affecting vegetation productivity is absorbed light, which is largely governed by chlorophyll. In this paper, we introduce the concept of chlorophyll efficiency, representing the amount of gross primary production per unit of canopy chlorophyll content (Chl) and incident PAR. We analyzed chlorophyll efficiency in two contrasting crops (soybean and maize). Given that they...