Understanding the water status of specific organs can be helpful in evaluating the life activities and growth conditions of maize. To accurately judge organ growth conditions and thus design appropriate interventions, it is necessary to clarify the true water dynamics of each maize organ. Using multiple maize cultivars with different growth periods, spatio-temporal water dynamics were analyzed here in the leaves, stalks, and ear components.
View Article and Find Full Text PDFIn this study, the content of iridoids and flavonoids in Tibetan medicine "Lanhua Longdan" was determined simul-taneously by quantitative analysis of multi-components by single marker(QAMS), which was used to verify the feasibility and applicability of the method in the application of Lanhua Longdan quality evaluation. Using HPLC with two typical elements gentiopicroside and isoorientin as the internal reference, the relative correction factor(RCF) between the mand loganin acid, swertiamarin, sweroside, isoscoparin-2″-β-D-glucopyranoside and isoscoparin was determined and then used, to calculate the content of several other components to achieve QAMS. At the same time, the external standard method(ESM) was used to determine the contents of these 7 components in the medicinal materials, and the differences were compared to verify the accuracy and feasibility of QAMS.
View Article and Find Full Text PDFJ Ethnobiol Ethnomed
August 2019
Background: Tibetan medicine (TM) and traditional Chinese medicine (TCM) are two independent traditional medical systems. Due to geographical factors, the development of Tibetan medicinal theory is relatively independent, but there are still many shared-use medicines in TM and TCM. However, a thorough and comparative study on those medicines is still absent.
View Article and Find Full Text PDFCrop agronomic parameters (leaf area index (LAI), nitrogen (N) uptake, total chlorophyll (Chl) content ) are very important for the prediction of crop growth. The objective of this experiment was to investigate whether the wheat LAI, N uptake, and total Chl content could be accurately predicted using spectral indices collected at different stages of wheat growth. Firstly, the product of the optimized soil-adjusted vegetation index and wheat biomass dry weight (OSAVI×BDW) were used to estimate LAI, N uptake, and total Chl content; secondly, BDW was replaced by spectral indices to establish new spectral indices (OSAVI×OSAVI, OSAVI×SIPI, OSAVI×CIred edge, OSAVI×CIgreen mode and OSAVI×EVI2); finally, we used the new spectral indices for estimating LAI, N uptake, and total Chl content.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
May 2012
The accurate wheat management needs a reasonable nitrogen application, and it is one of the key measures for real-time and quantitatively monitoring of nitrogen status to gain the higher yield of wheat. In the present study, two field experiments were conducted with different nitrogen stress and wheat cultivars, the relationship was analyzed between spectral parameters and the partial factor productivity from applied N (PFPn), and the estimating model was established for PFP, in the growth stages of wheat. The result indicated that there was a highly significant correlation between the PFP, and GreenNDVI at jointing, the correlation coefficient (r) was 0.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
July 2011
Cotton production for accurate non-destructive, rapid monitoring of plant nitrogen content there is an urgent demand. Canopy spectral characteristics of the cotton plant and its quantitative relationship between nitrogen content, can achieve non-destructive monitoring of cotton nitrogen. Two consecutive years by different nitrogen test, cotton canopy hyperspectral data collection and simultaneous determination of canopy nitrogen content, analysis of different fertilizer treatments of cotton canopy spectral characteristics and the relationship between nitrogen content of cotton, the results show that: nitrogen content of cotton plant in different periods and spectral reflectance in the visible band (400-700 nm) was negatively related to the near-infrared 700-1300 nm band was a significant positive correlation, and in the short-wave infrared 1300-1800 nm band correlation is more complicated.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
November 2010
The spectrum and physical-chemical parameters were measured on cotton leaves infected by aphid with different severity levels (SL) at main cotton growth periods. Meanwhile, the reflectance and physical-chemical parameters of cotton leaves infected by aphid were analyzed and compared in different cotton growth periods and varieties. The sensitivity wave bands of cotton leaves infected by aphid were confirmed, and the estimating models of leaves infected by aphid were established.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
November 2010
Biomass, leaf area index (LAI) and nitrogen status are important parameters for indicating crop growth potential and photosynthetic productivity in wheat. Nondestructive, quick assessment of leaf dry weight, LAI and nitrogen content is necessary for nitrogen nutrition diagnosis and cultural regulation in wheat production. In order to establish the monitoring model of nitrogen richness in winter wheat of growth anaphase, studying the relationship between the nitrogen richness (NR) containing nitrogen density, LAI and leaf dry weight and the difference of hyperspectral reflectance rates (deltaR), we conducted a comparable experiment with five winter wheat varieties under nitrogen application level of 0, 100, 200 and 400 kg x N x ha(-1).
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
February 2010
The spectrum reflectance and pigment contents of cotton leaves infected with Verticillium wilt were measured in cotton disease nursery and field in different growth phases, and severity level of Verticillium wilt was investigated. The correlation between pigment contents of cotton leaves with Verticillium wilt and spectra reflectance, the first derivative of reflectance and spectral characteristic parameters were analyzed respectively. The estimation models about leaves pigment contents of disease cotton were established and tested.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
December 2009
The correlation of cotton leaf verticillium wilt severity level with raw hyperspectral reflectance, first derivative hyperspectral reflectance, and hyperspectral characteristic parameters was analyzed. Using linear and nonlinear regression methods, the hyperspectral remote sensing retrieval models of verticillium wilt severity level with remote sensing parameters as independent variables were constructed and validated. The result showed that spectral reflectance increased significantly in visible and short infrared wave band with the increase in the severity level, and this is especially significant in visible band.
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