The Application of Terahertz Time-Domain Spectroscopy to Identification of Potato Late Blight and Fusariosis

Fusarium and late blight (fungal diseases of cereals and potatoes) are among the main causes of crop loss worldwide. A key element of success in the fight against phytopathogens is the timely identification of infected plants and seeds. That is why the development of new methods for identifying phytopathogens is a priority for agriculture. The terahertz time-domain spectroscopy (THz-TDS) is a promising method for assessing the quality of materials. For the first time, we used THz-TDS for assessing the infection of seeds of cereals (oats, wheat and barley) with fusarium and potato tubers of different varieties (Nadezhda and Meteor) with late blight. We evaluated the refractive index, absorption coefficient and complex dielectric permittivity in healthy and infected plants. The presence of phytopathogens on seeds was confirmed by microscopy and PCR. It is shown, that Late blight significantly affected all the studied spectral characteristics. The nature of the changes depended on the variety of the analyzed plants and the localization of the analyzed tissue relative to the focus of infection. Fusarium also significantly affected all the studied spectral characteristics. It was found that THz-TDS method allows you to clearly establish the presence or absence of a phytopathogens, in the case of late blight, to assess the degree and depth of damage to plant tissues.

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Investigation of Dielectric Properties of Polymers and their Discrimination Using Terahertz Time-Domain Spectroscopy with Principal Component Analysis

Applied Spectroscopy ◽

10.1177/0003702816675361 ◽

2016 ◽

Vol 71 (3) ◽

pp. 456-462 ◽

Cited By ~ 16

Author(s):

Muhammad Mumtaz ◽

Ahsan Mahmood ◽

Sabih D. Khan ◽

M. Aslam Zia ◽

Mushtaq Ahmed ◽

...

Keyword(s):

Spectral Range ◽

Time Domain ◽

Principal Component ◽

Component Analysis ◽

Thz Radiation ◽

Terahertz Time Domain Spectroscopy ◽

Time Domain Spectroscopy ◽

Styrene Acrylonitrile ◽

Characteristic Features ◽

First Time

Polymers are among the most commonly used materials in our everyday life. They are generally transparent to terahertz (THz) radiation, but are quite difficult to differentiate using optical techniques as few or no characteristic features exist in the spectral range of <2.0 THz for small and portable radiation systems. In this work, we report experimental measurement of refractive indices and absorption coefficients of styrene acrylonitrile (SAN) and Bakelite in the spectral range of 0.2–2.0 THz for the first time. Additionally, we demonstrate that by combining principle component analysis (PCA) with THz time-domain spectroscopy one can differentiate such polymers. In this analysis, the first three principle components PC1, PC2, and PC3 depict >94% variance with a distribution of 72.45%, 11.52%, and 9.38%, respectively.

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Applying broadband terahertz time-domain spectroscopy to the analysis of crystalline proteins: a dehydration study

Journal of Applied Crystallography ◽

10.1107/s0021889810043372 ◽

2010 ◽

Vol 44 (1) ◽

pp. 129-133 ◽

Cited By ~ 10

Author(s):

Katarzyna M. Tych ◽

Andrew D. Burnett ◽

Christopher D. Wood ◽

John E. Cunningham ◽

Arwen R. Pearson ◽

...

Keyword(s):

Time Domain ◽

Hen Egg White Lysozyme ◽

Terahertz Time Domain Spectroscopy ◽

Time Domain Spectroscopy ◽

Egg White Lysozyme ◽

Macromolecular Protein ◽

Hen Egg White ◽

Long Range Ordering ◽

First Time ◽

Lysozyme Crystals

The application of terahertz time-domain spectroscopy and imaging to the study of proteins in crystalline form is demonstrated. Terahertz time-domain spectroscopy is particularly sensitive to the long-range ordering of molecules, with proven utility for the spectroscopy of crystalline biological small molecules. Here, the terahertz time-domain absorption response of a macromolecular protein single crystal is investigated for the first time. In particular, the effect of dehydration on the terahertz absorption coefficient of tetragonal hen egg white lysozyme crystals is reported.

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Study of 2,4-D Spectral Characteristics and Its Detection in Zizania Latifolia Using Terahertz Time-Domain Spectroscopy

Applied Sciences ◽

10.3390/app9112248 ◽

2019 ◽

Vol 9 (11) ◽

pp. 2248

Author(s):

Pengcheng Nie ◽

Chengyong Cai ◽

Fangfang Qu ◽

Lei Lin ◽

Tao Dong ◽

...

Keyword(s):

Time Domain ◽

Density Functional ◽

Terahertz Spectroscopy ◽

Spectral Characteristics ◽

Geometry Optimization ◽

Main Peak ◽

Terahertz Time Domain Spectroscopy ◽

Zizania Latifolia ◽

Time Domain Spectroscopy ◽

2,4 Dichlorophenoxyacetic Acid

2,4-Dichlorophenoxyacetic acid (2,4-D) is a common plant growth regulator, which can remain in food and, with long-term consumption, threaten human health. Therefore, it is necessary to propose an effective detection method. Terahertz time-domain spectroscopy technique (THz-TDS) has good advantages in the quantitative and qualitative analysis of most biomolecules due to its rich fingerprint characteristics. In this paper, density functional theory (DFT) was applied to geometry optimization and frequency vibration calculation of 2,4-D, and THz-TDS was used to quantitatively detect 2,4-D in Zizania latifolia. The results showed that there were three characteristic absorption peaks of 2,4-D at 1.36, 1.60, and 2.38 THz, respectively, and the theoretical spectra were in good consistency with experimental spectra, with slight discrepancies. Additionally, the absorption peak at 1.36 THz had the best absorption characteristics and was chosen as the main peak for 2,4-D quantitative analysis. It was demonstrated that the limits of detection (LOD) of 2,4-D in Zizania latifolia were found to be as low as 5%, the absorbance intensity at 1.36 THz showed a good linear relationship (R2 = 0.9854) with 2,4-D concentration from 5% to 30%, and the recovery was 93.29%–98.75%. Overall, this work enriched the fingerprint database of pesticide molecules on the basis of terahertz spectroscopy and could provide a technical support for the detection of 2,4-D in food by terahertz spectroscopy.

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The Study of Terahertz Time-Domain Spectroscopy of Benzoyl Peroxide

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.633-634.521 ◽

2014 ◽

Vol 633-634 ◽

pp. 521-525

Author(s):

Zhi Long Zhou ◽

Xiai Chen ◽

Lu Han ◽

Qing Hua Zhang ◽

Xian Li

Keyword(s):

Experimental Study ◽

Benzoyl Peroxide ◽

Absorption Spectra ◽

Time Domain ◽

Spectral Characteristics ◽

Experimental Result ◽

Wave Band ◽

Terahertz Time Domain Spectroscopy ◽

Time Domain Spectroscopy ◽

Terahertz Absorption

The spectral characteristics of benzoyl peroxide in the range of 0.3 to 1.6 in THz region is obtained by THz time-domain spectroscopy, the refraction and absorption spectra of benzoyl peroxide is got,meanwhile. The experimental result shows that, the benzoyl peroxide has the absorption peak at the wave band of 0.36621THz,0.498THz,0.92285THz,1.11328THz, the most obvious of which is at the wave band of 0.92285THz.The terahertz absorption spectra of the mixture of flour and benzoyl peroxide is studied at the same time.This experimental study provides a new method to detect benzoyl peroxide illegally added in food.

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Efficiency of application of “Epin-extra” and “Zircon” biostimulants on potato landings in agroecological conditions of Republic of North Ossetia-Alania

Agrarian Bulletin of the ◽

10.32417/1997-4868-2020-199-8-2-8 ◽

2020 ◽

Vol 199 (8) ◽

pp. 2-8

Author(s):

Irina Gazdanova ◽

Fatima Gerieva ◽

T. Morgoev

Keyword(s):

Late Blight ◽

Quality Indicators ◽

Plant Resistance ◽

Mineral Fertilizers ◽

Potato Tubers ◽

High Level ◽

First Time ◽

North Ossetia ◽

Phenological Phases

Abstract. Recently, the trend of agricultural biologization has been gaining great importance. When cultivating crops, the use of biostimulants helps to improve the environment and produce environmentally friendly products. The purpose of the work is to identify the effectiveness of the use of biostimulants “Epin-extra” and “Zircon” in the cultivation of potatoes on the background of minimal doses of mineral fertilizers. Impact on productivity, morbidity and quality indicators of tubers. The novelty lies in the fact that for the first time in the agroecological conditions of the foothill zone of North Ossetia-Alania, the effectiveness of the use of the “Epin-Extra” and “Zircon” biostimulants on the indicators of productivity and quality of potato varieties was studied. Methods Accounting and observations were carried out according to generally accepted methods described in the “Educational-methodical guide for research in agronomy”. Results. As a result of the use of biostimulants “Epin-extra” and “Zircon” in combination with minimal doses of mineral fertilizers, they contribute to a reduction in the passage of the phenological phases of plants compared to the control by 8–9 days. The processing of potato tubers before planting “Epin-extra” and “Zircon” in combination with mineral fertilizers in minimum doses provided a high level of yield, on the Background 1 + “Epin-extra” variant by varieties: 33.7–39.1 t/ha. The biostimulants “Epin-extra” and “Zircon” possess not only growth-regulating properties, but also inhibit the development of diseases, in particular, increase plant resistance to late blight by 4.6–6.5 %.

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