نتایج جستجو برای: leaf chlorophyll meter

تعداد نتایج: 127595  

2003
Alena Torres Netto Eliemar Campostrini Jurandi Gonçalves de Oliveira Osvaldo Kiyoshi Yamanishi

The techniques utilized to extract chlorophyll from plant materials are destructive and based on methods that use organic solvents. This study proposes the non-destructive quantification of chlorophyll and nitrogen concentration using a portable chlorophyll meter (SPAD-502). Further, was possible to establish relationships between chlorophyll fluorescence and SPAD-502 values. This methodology c...

Journal: :Journal of plant physiology 2016
Anatoly A Gitelson Yi Peng Andrés Viña Timothy Arkebauer James S Schepers

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...

Journal: :Biochemical and biophysical research communications 2013
Yasuhito Sakuraba Ye-Sol Kim Soo-Cheul Yoo Stefan Hörtensteiner Nam-Chon Paek

During natural or dark-induced senescence, chlorophyll degradation causes leaf yellowing. Recent evidence indicates that chlorophyll catabolic enzymes (CCEs) interact with the photosynthetic apparatus; for example, five CCEs (NYC1, NOL, PPH, PAO and RCCR) interact with LHCII. STAY-GREEN (SGR) and CCEs interact with one another in senescing chloroplasts; this interaction may allow metabolic chan...

2014
Denise Johnstone Michael Tausz Gregory Moore Marc Nicolas

Wood structure and wood anatomy are usually considered to be largely independent of the physiological processes that govern tree growth. This paper reports a statistical relationship between leaf and bark chlorophyll fluorescence and wood density. A relationship between leaf and bark chlorophyll fluorescence and the quantity of wood decay in a tree is also described. There was a statistically s...

2014
Hu Yang Jinwen Li Jingping Yang Hua Wang Junliang Zou Junjun He

A Soil-Plant Analysis Development (SPAD) chlorophyll meter can be used as a simple tool for evaluating N concentration of the leaf and investigating the combined effects of nitrogen rate and leaf age on N distribution. We conducted experiments in a paddy field over two consecutive years (2008-2009) using rice plants treated with six different N application levels. N distribution pattern was det...

2004
J. Ojala W. DeTar J. Chesson V. Penner

Acala cotton (Gossypium hirsutum, var. Maxxa) was planted into a split-plot factorial design field trial on the Shafter Research and Extension Center, Shafter, CA. The two main treatments were optimum irrigation (Io) and stressed irrigation (Is) containing five levels of soil nitrogen availability (-100, -50, optimum, +50, and +100 lbs N/ac). The objective of this field trial was to determine i...

Journal: :Hortscience 2022

Hydroponic systems have become increasingly popular for growers in recent years year-round local production. Whereas optimal air temperature plant growth has been considered, root zone temperatures not examined as thoroughly. The objective of this research was to determine the water growing different types basil hydroponically. Research conducted at greenhouses Stillwater, OK. Seventeen cultiva...

Journal: :Plant physiology 1980
S A Boffey G Selldén R M Leech

A method is described for relating the age of a cereal leaf cell to its distance from the leaf base. The rates of chlorophyll synthesis per plastid in the first leaf of light-grown and of greening etiolated seedlings of wheat (Triticum aestivum, var. Maris Dove) increase with cell age. Normally developing plastids of light-grown wheat take over 24 hours to reach the chlorophyll a/b ratio charac...

Journal: :Food Research 2021

Leaf color is a good indicator of plant’s health status. In this study, new image acquisition technique was developed to estimate chlorophyll content lettuce leaves. The images leaves grown under artificial light were acquired using smartphone. Leaves captured by directly attached the camera lens with aid background illumination from SMD LED. Red, green, blue (RGB) indices extracted and some ve...

2005
William W. Adams Peter Schramel

The loss of chlorophyll and total leaf nitrogen during autumnal senescence of leaves from the deciduous tree Platanus occidentalis L. was accompanied by a marked decline in the photosynthetic capacity of 02 evolution on a leaf area basis. When expressed on a chlorophyll basis, however, the capacity for lightand C02-saturated O2 evolution did not decline, but rather increased as leaf chlorophyll...

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