Remobilization of mineral nutrients from leaves to reproductive structures is a possible regulatory factor in leaf senescence. The relationship between P remobilization from leaves of soybean (Glycine max [L.] Merr. cv McCall) during reproductive development and leaf senescence was determined by utilizing soil P treatments that supplied deficient, optimum, and supraoptimum soil P levels. The so...

We investigated sex-related photosynthetic responses to drought in the dioecious species, Populus cathayana Rehd. Plants were subjected to two watering regimes (100% and 30% of field capacity) in a semi-controlled environment. Drought significantly decreased leaf area (LA), total number of leaves (TNL), specific leaf area (SLA), relative water content, net photosynthetic rate (P(n)), transpirat...

1. Aqueous extracts of spinach and Aspidistra leaves yield highly opalescent preparations which are not in true solution. Such extracts differ markedly from colloidal chlorophyll in their spectrum and fluorescence. The differences between the green leaf pigment and chlorophyll in organic solvents are shown to be due to combination of chlorophyll with protein in the leaf. 2. The effect of some a...

Knowledge of foliar nitrogen (N) concentration is important in pecan [Carya illinoinensis (Wang.) K. Koch] management protocols. Lower cost and/or rapid methods to determine foliar N are desirable and may result in improved management strategies as well as enable precision agricultural practices to be deployed in pecan production. This study investigates using a portable chlorophyll meter and V...

Longleaf pine has been classified as very shade intolerant but leaf physiological plasticity to light is not well understood, especially given longleaf pine’s persistent seedling grass stage. We examined leaf morphological and physiological responses to light in one-year-old grass-stage seedlings and young trees ranging in height from 4.6 m to 6.3 m to test the hypothesis that young longleaf pi...

a greengouse experiment was conducted to evaluation of salinity stress on growth parameters of two olive cultivars during 2013-2014 at agricultural and natural resources research center of tehran. in the experiment, effects of five levels of irrigation water salinity including 0, 4, 8, 12 and 16 ds.m-1 were evaluated on ʻzardʼ and ʻmissionʼ olive cultivars under soilless culture. data showed th...

wheat crop, considering its high planting area and consumption at national scale, demand a regular yield increase. humic acid, as an organic acid obtained from humus and organic sources without any environmental destructive effects, improves wheat yield particularly in variable environment conditions. in order to evaluate the effects of different levels of humic acid on shoot and wheat yield, a...

The effect of automobile pollution was determined on chlorophyll content of four different tree species viz. Azadirachta indica L., Conocarpus erectus L., Guiacum officinale L.and Eucalyptus sp. growing along the roads of the city.  Significant changes in the level of chlorophyll “a”, chlorophyll “b” and total chlorophyll “a+b” were found in the leaves of fou...

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 ...