I evaluated the use of global remote sensing techniques for estimating plant leaf chlorophyll a + b (C(ab); μg cm(-2)) and water (C(w); mg cm(-2)) concentrations as well as the ratio of C(w)/C(ab) with the PROSAIL model under possible distributions for leaf and soil spectra, leaf area index (LAI), canopy geometric structure, and leaf size. First, I estimated LAI from the normalized difference v...

In order to detect leaf chlorophyll level nondestructively and instantly, VIS/NIR reflection spectroscopy technique was examined. In the test, 70 leaf samples were collected for model calibration and another 50 for model verification. Each leaf sample was optically measured by USB4000, a modular spectrometer. By the observation of spectral curves, the spectral range between 650nm and 750nm was ...

Leaf chlorophyll content in coniferous forest canopies, a measure of stand condition, is the target of studies and models linking leaf reflectance and transmittance and canopy hyperspectral reflectance imagery. The viability of estimation of needle chlorophyll content from airborne hyperspectral optical data through inversion of linked leaf level and canopy level radiative transfer models is di...

Assessing photosynthesis rates with remote sensing is important for tracking the physiological state of plants. The photochemical reflectance index (PRI) is a good estimator of short-term light-use efficiency (LUE) at the leaf scale but its responses to environmental factors are poorly understood. In this study, we assessed changes in the responses of the PRI to ozone exposure and to an increas...

Chlorophyll degradation is vital during leaf senescence and fruit ripening, as it allows for recycling of nitrogen and other nutrients and for protection from buildup of phototoxic chlorophyll intermediates (Hörtensteiner, 2006). The first steps in chlorophyll breakdown are the removal of the phytol tail (dephytylation) and the central Mg atom. It has been thought that dephytylation typically o...

The canopy photosynthesis and carbon balance of the subtropical forests are not well studied compared to temperate and tropical forest ecosystems. The main objective of this study was to assess the seasonal dynamics of Normalized Difference Vegetation Index (NDVI) and potential canopy photosynthesis in relation to seasonal changes in leaf area index (LAI), chlorophyll concentration, and air tem...

A field experiment was performed to study the effects of waterlogging on the leaf mesophyll cell ultrastructure, chlorophyll content, gas exchange parameters, chlorophyll fluorescence, and malondialdehyde (MDA) content of summer maize (Zea mays L.) hybrids Denghai605 (DH605) and Zhengdan958 (ZD958). The waterlogging treatments were implemented for different durations (3 and 6 days) at the third...

abstract to investigate the effects of paclobutrazol (pbz) on vegetative and reproductive growth of strawberry cv. selva a factorial experiment in a completely randomized design with three replications was carried out in greenhouse of agriculture college, isfahan university of technology. pbz was applied in two methods, drench and foliar spray, at 0, 0.5, 1, 1.5 and 2 mg active ingredient per p...

application of salicylic acid (sa) as a phytohormone has been increased due to resistance to stresses such as drought. the main goal of this experiment was to evaluate the effects of sa on morphological and physiological characteristics of cucumber seedlings under drought stress. for this purpose a factorial trial based on completely randomized design was conducted with 5 levels of sa (0 (contr...

in this research, catalase activity and leaf chlorophyll stability of satsuma mandarin on some citrus rootstocks under waterlogging condition were studied. experiment was conducted as factorial with randomized complete blocks and 6 replications. the first factor, include 7 soils from east mazandaran and the second factor included 7 different citrus rootstocks: 1. sour orange, 2. swingle citrome...