Significant Differences In Reflectance Research Articles

Phenotyping and Exploitation of Kompetitive Allele-Specific PCR Assays for Genes Underpinning Leaf Rust Resistance in New Spring Wheat Mutant Lines.

Leaf rust (Puccinia triticina Eriks) is a wheat disease causing substantial yield losses in wheat production globally. The identification of genetic resources with permanently effective resistance genes and the generation of mutant lines showing increased levels of resistance allow the efficient incorporation of these target genes into germplasm pools by marker-assisted breeding. In this study, new mutant (M3 generation) lines generated from the rust-resistant variety Kazakhstanskaya-19 were developed using gamma-induced mutagenesis through 300-, 350-, and 400-Gy doses. In field trials after leaf rust inoculation, 75 mutant lines showed adult plant resistance. These lines were evaluated for resistance at the seedling stage via microscopy in greenhouse experiments. Most of these lines (89.33%) were characterized as resistant at both developmental stages. Hyperspectral imaging analysis indicated that infected leaves of wheat genotypes showed increased relative reflectance in visible and near-infrared light compared to the non-infected genotypes, with peak means at 462 and 644 nm, and 1936 and 2392 nm, respectively. Five spectral indexes, including red edge normalized difference vegetation index (RNDVI), structure-insensitive pigment index (SIPI), ratio vegetation index (RVSI), water index (WI), and normalized difference water index (NDWI), demonstrated significant potential for determining disease severity at the seedling stage. The most significant differences in reflectance between susceptible and resistant mutant lines appeared at 694.57 and 987.51 nm. The mutant lines developed were also used for the development and validation of KASP markers for leaf rust resistance genes Lr1, Lr2a, Lr3, Lr9, Lr10, and Lr17. The mutant lines had high frequencies of "a" resistance alleles (0.88) in all six Lr genes, which were significantly associated with seedling resistance and suggest the potential of favorable haplotype introgression through functional markers. Nine mutant lines characterized by the presence of "b" alleles in Lr9 and Lr10-except for one line with allele "a" in Lr9 and three mutant lines with allele "a" in Lr10-showed the progressive development of fungal haustorial mother cells 72 h after inoculation. One line from 300-Gy-dosed mutant germplasm with "b" alleles in Lr1, Lr2a, Lr10, and Lr17 and "a" alleles in Lr3 and Lr9 was characterized as resistant based on the low number of haustorial mother cells, suggesting the contribution of the "a" alleles of Lr3 and Lr9.

Comparison of UAS and Sentinel-2 Multispectral Imagery for Water Quality Monitoring: A Case Study for Acid Mine Drainage Affected Areas (SW Spain)

Uncrewed Aerial Systems (UAS) and satellites are used for monitoring and assessing the quality of surface waters. Combining both sensors in a joint tool may scale local water quality retrieval models to regional and global scales by translating UAS-based models to satellite imagery. The main objective of this study is to examine whether Sentinel-2 (S2) data can complement UAS data, specifically from the MicaSense RedEdge MX-Dual sensor, for inland water quality monitoring in mining environments affected by acid mine drainage (AMD). For this purpose, a comparison between UAS reflectance maps and atmospherically corrected S2 imagery was performed. S2 data were processed with Case 2 Regional Coast Colour (C2RCC) and Case 2 Regional Coast Colour for Complex waters (C2X) atmospheric correction (AC) processors. The correlation between the UAS data and the atmospherically corrected S2 data was evaluated on a band-by-band and a pixel-by-pixel basis, and the compatibility of the spectral data was analyzed through statistical methods. The results showed C2RCC and C2X performed better for acidic greenish-blue and non-acidic greenish-brown water bodies concerning the UAS data than for acidic dark reddish-brown waters. However, significant differences in reflectance between the UAS sensor and both S2 AC processors have been detected. The poor agreement between sensors should be considered when combining data from both instruments since these could have further consequences in developing multi-scale models.

Petrographic and chemical structure characteristics of amorphous organic matter in marine black shales: Insights from Pennsylvanian and Devonian black shales in the Illinois Basin

Amorphous organic matter (AOM or bituminite) is a major oil-prone liptinite maceral in black shales that can be classified into two main types: low-reflectance AOM and micrinized AOM. In this study, we investigated the petrographic and chemical structure characteristics of these two types of AOM and discussed their origin based on 15 marine black shale samples from the Illinois Basin, including 5 samples from the Pennsylvanian shales and 10 samples from the Upper Devonian New Albany Shale. The studied samples are at early mature stage, with mean vitrinite reflectance ranging from 0.64 to 0.74%. Low-reflectance AOM is the dominant organic matter (OM) in all samples and micrinized AOM is common only in the Pennsylvanian strata but is very rare in the New Albany Shale. There are significant differences in reflectance, petrographic characteristics, and chemical structure characteristics between low-reflectance and micrinized AOM. Low-reflectance AOM has a reflectance of 0.30 to 0.57%, whereas the reflectance of micrinized AOM is typically >1.0%, which makes micrinized AOM brighter than low-reflectance AOM under an optical microscope. Both types of AOM have heterogeneous texture, occur as structureless organic streaks or lenses, and have abundant clay-sized mineral inclusions. Compared to micrinized AOM, low-reflectance AOM has lower aromaticity and higher aliphatic chain length (inferred from the CH2/CH3 ratio). Based on the petrographic and chemical functional groups characteristics, we proposed evolutionary pathways for the formation of low-reflectance and micrinized AOM in marine black shales during early diagenesis. AOM is originally derived from microbially degraded phytoplankton. Low-reflectance AOM formed in the fermentation zone through microbial degradation of phytoplankton by anaerobic bacteria. In comparison, micrinized AOM is a product of an advanced degree of microbial degradation of phytoplankton by aerobic bacteria that preferentially consume aliphatic functional groups over aromatics in the oxidation zone. Different depositional environments and subsequent diagenetic alterations resulted in the difference in micrinized AOM content between the New Albany Shale and Pennsylvanian shales. This study provides a better understanding of the origin, formation, and thermal maturation of dispersed AOM in black shale successions.

Comparison of UAV-based multispectral sensors for detection of Solenopsis invicta Nests

The invasive red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae) has been continuing to expand its range in China, resulting in adverse ecological impacts to where it has invaded. As such, the reliable detection of Solenopsis invicta Buren nests is needed to effectively manage the species. In this paper, the spectral features of the Solenopsis invicta Buren nests were demonstrated using spectra samples obtained by ASD FieldSpec 4 during field surveys in Shanggao County, Jiangxi Province. Furthermore, channel reflectance estimations for three unmanned aerial vehicle (UAV)-based multispectral sensors were simulated correspondingly. Based on the channel reflectance from individual sensors, the detection of the Solenopsis invicta Buren nests was investigated. Generally, between-class differences in reflectance were relatively significant in both Green channel and Red channel, which suggests the importance of these two channels for the detection of Solenopsis invicta Buren nest. Minor between-sensor differences observed in both Green channel and Red channel suggest that detection results obtained from UAV-based multispectral observations could be comparable among the three sensors, considering only the spectral features. There are significant differences in reflectance between the soil of Solenopsis invicta Buren nests and ordinary soil over the longwave region of near infrared (NIR). It suggests the spectral measurement over the longwave region of NIR could be more useful in distinguishing the soil of Solenopsis invicta Buren nests from ordinary soil. Nevertheless, the multispectral sensors provided with channels covering visible and the shortwave region of NIR, possibly do not meet requirements completely for application. An effective method for detecting Solenopsis invicta Buren nests using UAV-based multispectral sensors is currently being evaluated.

Measurement of refractive indices of tunicates\u2019 tunics: light reflection of the transparent integuments in an ascidian Rhopalaea sp. and a salp Thetys vagina

BackgroundTunic is a cellulosic, integumentary matrix found in tunicates (Subphylum Tunicata or Urochordata). The tunics of some ascidian species and pelagic tunicates, such as salps, are nearly transparent, which is useful in predator avoidance. Transparent materials can be detected visually using light reflected from their surfaces, with the different refractive indices between two media, i.e., tunic and seawater, being the measure of reflectance. A larger difference in refractive indices thus provides a larger measure of reflectance.ResultsWe measured the refractive indices of the transparent tunic of Thetys vagina (salp: Thaliacea) and Rhopalaea sp. (ascidian: Ascidiacea) using an Abbe refractometer and an ellipsometer to estimate the light reflection at the tunic surface and evaluate the anti-reflection effect of the nipple array structure on the tunic surface of T. vagina. At D-line light (λ = 589 nm), the refractive indices of the tunics were 0.002–0.004 greater than seawater in the measurements by Abbe refractometer, and 0.02–0.03 greater than seawater in the measurements by ellipsometer. The refractive indices of tunics were slightly higher than that of seawater. According to the simulation of light reflection based on rigorous coupled wave analysis (RCWA), light at a large angle of incidence will be completely reflected from a surface when its refractive indices are smaller than seawater. Therefore, the refractive index of integument is important for enabling transparent organisms to remain invisible in the water column.ConclusionIn order to minimize reflectance, the refractive index should be similar to, but never smaller than, that of the surrounding seawater. The simulation also indicated that the presence or absence of a nipple array does not cause significant difference in reflectance on the surface. The nipple array on the tunic of the diurnal salp may have another function, such as bubble repellence, other than anti-reflection.

The use of hyperspectral imaging in the VNIR (400–1000 nm) and SWIR range (1000–2500 nm) for detecting counterfeit drugs with identical API composition

The risk of death from taking counterfeit drugs is now greater than the probability of dying from malaria and AIDS combined (at least half a million deaths each year). At the same time, counterfeit medicines are falsified more and more “skillfully”. According to WHO about 10% of counterfeit drugs are copies of original products.The methods of hyperspectral imaging and image analysis and processing were used to detect counterfeit drugs.Original Viagra® (Pfizer) and counterfeit tablets were compared. Hyperspectral imaging was used to acquire hyperspectral data cubes from both original and counterfeit tablets in the spectral range of 400–2500nm. Spectral parameters for both the original Viagra® and counterfeit drugs were compared. Grey-Level Co-Occurrence Matrix (GLCM) analysis and Principal Component Analysis (PCA) were performed.Hyperspectral analysis of the surface of the original Viagra® and counterfeit tablets demonstrates significant differences in reflectance (maximum difference for 1619.75nm). The GLCM contrast for the falsified drug is on average higher than for the original one 16±4%.GLCM contrast analysis enables to quantify homogeneity of distribution of tablet ingredients and enables to distinguish tablets with identical chemical composition. SWIR (1000–2500nm) hyperspectral imaging has a definite advantage over imaging in VNIR (400–1000nm) – higher wavelength is less sensitive to non-uniform illumination.

Wideband reflectance measurements in newborns: Relationship to otoscopic findings

ObjectivesNewborn hearing screening includes testing with otoacoustic emissions and the auditory brainstem response. Unfortunately, both tests are affected by the presence of material in the ear canal and middle ear such as vernix, meconium, and amniotic fluid. The objective of this study was to determine to what extent occlusion of the ear canal as seen on otoscopy affects wideband energy reflectance measurements in newborns. A secondary objective was to obtain additional normative wideband reflectance data in newborns. MethodsNewborns from a well-baby nursery were enrolled. Wideband energy reflectance measurements and otoscopy were done immediately after the hearing screening. Occlusion of the ear canal as seen on otoscopy was described on a scale of 0–100%. ResultsA total of 156 babies were enrolled (mean age = 25 hours). A statistically significant difference in the reflectance at ambient pressure was found between the 0–70% and 80–100% occlusion groups. There was no significant difference in reflectance between the right and the left ears. The median reflectance pattern generally followed that of previous studies but in certain frequency regions the present reflectance values were higher. ConclusionA significant increase in reflectance occurs when 70%–80% of the ear-canal diameter is occluded. Taking otoscopy findings into account may improve the interpretation of reflectance measurements. However, further studies are required to better establish the relationship between canal occlusion and reflectance.

Influence of hemlock woolly adelgid infestation on the physiological and reflectance characteristics of eastern hemlock

The hemlock woolly adelgid (HWA) (Adelges tsugae Annand) is an invasive insect in the eastern United States. Since its initial detection in Richmond, Virginia, in 1951, HWA has spread to half of the eastern hemlock (Tsuga canadensis (L.) Carr.) natural range. Detection of early infestation symptoms via remote sensing requires the knowledge of the changes in reflectance resulting from physiological changes in the host as inflicted by the insect and the selection of equipment with the appropriate sensor characteristics. Laboratory-based reflectance measurements of infested and non-infested hemlock foliage collected from four sites in southern New Hampshire and Maine occurred biweekly over 6 months in 2012 and weekly over 5 weeks in 2013. Vegetation indices (red edge inflection point (REIP), normalized difference vegetation index (NDVI), moisture stress index (MSI), and near infrared (NIR) 3/1 ratio) were associated with concurrent chlorophyll and moisture content data. Infested first-year foliage contained greater concentrations of chlorophyll and moisture, resulting in reduced visible spectral reflectance, greater REIP and NDVI values, and lower MSI and NIR 3/1 values than non-infested foliage. Furthermore, fluorescence measurements indicated greater photosystem function during the early stages of infestation, suggesting a possible compensatory response by hemlock to infestation. Significant differences in reflectance between infested and non-infested foliage were observed in late June and July in the weeks immediately following HWA settlement on new growth. Implementing these observations during remote sensing mission planning may increase the likelihood of detecting early HWA infestation symptoms at landscape scales.

Determination of nitrogen and water stress with hyper spectral reflectance on maize using classification tree (CT) analysis

Field experiments were conducted at the Tamil Nadu Agricultural University, Coimbatore, Tamilnadu, India during rabi (winter) season of 2013-14 with maize crop (TNAU maize hybrid Co 6). To ensure the stressed environment, the crop was subjected to two irrigation levels (IW/CPE: 0.80 and 0.50) and five staggered nitrogen levels (0, 50, 75, 100 and 125 % of recommended dose of nitrogen (RDN).The experiment was laid out in factorial randomized blocks design RBD (Factorial) with three replications. Hyper spectral observations were made with spectroradiometer GER 1500 at 60 and 90 days after sowing (DAS). Measured spectral reflectance curve of maize exhibited a broad low intensity peak centered in the green region at 550 nm and a sharp rise starting at about 675 nm to a plateau in the vicinity of 762 nm under unstressed environment created with irrigation at 0.80 IW/CPE ratio and fertilizer application at 100 % RDN. Significant differences in reflectance were established for nitrogen and water stress at green and NIR region. The results of Classification tree analysis revealed that nitrogen and water stress can be assessed and differentiated using reflectance data when transformed into spectral vegetation indices viz., NDVI, GNDVI, RVI, LCI, IR-RED and SR. Further the Classification tree algorithm coulddetermine that NDVI was the most effective index to assess the combined effect of nitrogen and water stress in maize crop.

Using leaf spectral reflectance to monitor the effects of shading on nicotine content in tobacco leaves

The objectives of this study were to determine the relationship between tobacco leaf nicotine content and leaf spectral reflectance, to identify specific regions of the light spectrum that could be used to detect nicotine content, and to develop spectral indices and quantitative models for quick and accurate estimation of nicotine content in flue-cured tobacco leaves under different shade conditions. The flue-cured tobacco cultivar Yunyan 87 was subjected to shade treatments in the field extending from the root elongation stage through the vigorous growth and maturing stages. Three shade treatments of 85% (S1), 65% (S2), and 45% (S3) of full solar radiation (S0, control) were applied and the nicotine, pigment, and nitrogen content and spectral reflectance of tobacco leaves were measured over a time course. Normalized difference vegetation indices (NDVI) and spectral ratio (SR) indices based on leaf reflectance spectra from 350 to 2500nm and correlations with nicotine content were determined. Shading significantly increased the nicotine content during the maturing stage. Significant differences in reflectance were measured for different shade treatments during the vigorous growth stage particularly at 350–700nm in the visible range and 750–1000nm in the near-infrared range. There was a significant correlation between nicotine content and nitrogen and pigment content. The regions of the spectrum that gave the best indication of nicotine content in flue-cured tobacco leaves were 420–750nm in the visible range in combination with 1400–1800nm and 2000–2400nm in the short-wave infrared range. Optimal spectral indices for SR (R450, R500) and NDVI (R2150, R610) were derived from measurements in these ranges. We also established linear models based on the spectral indices derived from field data gathered in 2012 for NDVI (R2150, R610), SR (450, 500), stepwise multiple linear regression (SMLR), and a back-propagation (BP) neural network with R2 values of 0.796, 0.810, 0.842, and 0.968, respectively. The linear models were validated using an independent data set from 2011 with RMSE values of 0.784, 0.958, 0.883, and 0.109 for NDVI (R2150, R610), SR (450, 500), SMLR, and the BP neural network, respectively. The results indicated that hyperspectral remote sensing can be used for quick and accurate monitoring of the leaf nicotine content and shading status of flue-cured tobacco crops.

Effects of Mycorrhiza on Fiber Quality Parameters, Root Characteristics and Yield of Organic Cotton (Gossypium Hirsutum L.)

Organic cotton consists of a new industrial crop product. Field experiment was conducted to determine the effects of mycorrhiza on fiber quality parameters and yield components of cotton crop (Gossypium hirsutum L.). The experiments, conducted during 2006 and 2007, were laid out in a split plot design with four replicates, two main plots (organic and conventional system) and two sub-plots (cotton varieties: Athena and Fandom). There were statistically significant differences in reflectance between these two varieties. Moreover, there were correlation between lint characteristics and regression as well as linear functions between AMF and statistical important values of lint characteristics.

An experimental approach to the measurement of the effects of water depth and substrate on optical and near infra‐red reflectance: a field‐based assessment of the feasibility of mapping submerged instream habitat

This study represent an assessment of the feasibility of using optical and near infra‐red wavelengths to map water depth and substrate type which are two of the primary components of river physical habitat. The objective was met by measuring reflectance using field spectroscopy of exposed and then progressively submerged (0–1 m) artificial substrates during rising tides on a tidal reach of the River Forth; this approach provided absolute control for substrate type. The field data were used to simulate multi‐spectral response as measured using Airborne Thematic Mapper (bands 1 to 7; 420nm to 900nm) since airborne remote sensing provides the way forward for synoptic mapping of small streams (<20 m), such as those typically found in Scotland. In the presence of sunlit conditions significant differences in reflectance over a broad range of wavelengths was evident with strong correlations with water depth and substrate. Differences in reflectance were most marked under shallow conditions (<0.75 m) and then progressively diminished. Application of simple linear correlation, band ratios, the Lyzenga algorithm and multiple discriminant analysis all suggested the possibility of mapping shallow river channel water depths. The results also showed that substrate type and the analysis technique selected also affected the optimum spectral wavelength for detection of channel substrate type and water depth. Overall the work suggests mapping channel depth and substrate type is possible using remotely sensed data in optical and near infra‐red wavelengths, using high spatial and spectral resolution multi‐spectral imagery. However it may be restricted to depths of less than 1 m where there is high organic colour and/or a significant periphyton cover.

Influence of plant pigments on spectral reflectance of maize, groundnut and soybean grown in semi-arid environments

. Spectral reflectance of leaves is influenced primarily by plant pigments, chlorophyll and carotenoids. Such reflectance can be used to study the changes in chlorophyll content and nitrogen status and in turn measures the amount of biomass accumulation. A field experiment was laid out at the Research Farm of ANGR Agricultural University, Hyderabad. The reflectance observations were taken using a hand-held ground radiometer at an interval of 15 days beginning from 30 days after sowing (DAS) until harvest of the crops. The plant pigments were determined simultaneously using DMSO (dimethyl sulphoxide) method in the laboratory. The experimental results revealed the influence of plant pigments on spectral reflectance of maize, groundnut and soybean. It was observed that there was an increase in chlorophyll- a, chlorophyll- b, total chlorophyll and carotenoid content up to flowering and thereafter chlorophyll- a content declined at a faster rate than chlorophyll- b towards physiological maturity. With the increase in concentrations of chlorophyll and carotenoids, there was a decline in spectral reflectance of the blue band (450-520 nm) and the red band (620-680 nm). Whereas, NIR (near-infrared) reflectance in the case of soybean and groundnut was found to be higher than that of maize by 11% and 2%, respectively. This was attributed to canopy cover of soybean and groundnut crops, where the soil was fully covered with vegetation. In case of maize, due to wider spacing, the soil exposure is greater, which results in low reflectance values of the NIR band. Normalized Difference Vegetation Index (NDVI) is linearly related to total chlorophyll content and the growth stages of a crop up to flowering. The NDVI differs significantly during the peak vegetative growth period among the three crop types. The study revealed that the significant differences in reflectance of maize, groundnut and soybean in the red and NIR bands were influenced by concentrations of chlorophyll- a, chlorophyll- b and carotenoids, which indicates the photosynthetic behaviour of the crops.

Reflection of ultraviolet radiation from different skin types.

In this study using 43 male subjects, the spectral reflectance of ultraviolet radiation (UVR) has been measured from the skin of each subject's forearm. The total diffuse reflectance and directional characteristics of reflection were determined for different wavelengths. Mean values were determined for four skin types in both the ultraviolet A (UVA) and ultraviolet B (UVB) range from 280 to 400 nm. Reflection occurs in all directions and with cylindrical symmetry that is normal to the skin surface. The ability of skin to reflect UVR decreases rapidly with decreasing wavelength. Reflection is as high as 20% for 400 nm and falls below 1% at 280 nm. Average UVA (315 to 400 nm) reflectance can reach 12%, but is only about 2.5% in the UVB (280 to 315 nm) spectral range. The significant differences in reflectance occur between different skin types and are determined primarily by complexion. Skin types with moderate sensitivity to solar radiation, neither too pale nor too tanned, reflect the greatest UVR. In this skin type the protective mechanism of reflection dominates over a mechanism based upon the absorption of UVR by melanin pigment.

Detection of canopy water stress in conifers using the Airborne Imaging Spectrometer

Imagery was acquired by the Airborne Imaging Spectrometer (AIS-2) over adjacent plots of control (natural) and water-stressed canopies of Norway spruce and white pine, and analyzed for differences in near-infrared reflectance features. Water stress had been induced in the trees by severing the sapwood and was assessed with shoot water potential (ψ) and relative water content (RWC) measurements. Stressed Norway spruce was found to have approximately 20% greater relative reflectance in the 1.0–1.3 μm region compared to the control canopy in the image obtained at 0925 h 13 days after stress induction. The difference in ψ and RWC between stressed and control was measured at 1.2 MPa and estimated at 7%, respectively. However, the difference in reflectance decreased to insignificance in the image taken at 1219 h that same day when the differences in ψ and RWC were approximately 0.72 MPa and 5%. In white pine, no significant differences in reflectance between stressed and control canopies were found in images obtained 14 days and 20 days after treatment with estimated differences in ψ and RWC of 0.3 MPa and 6%. Because extensive ground data was required at times of AIS-2 overflights to detect these small reflectance differences, we believe that water stress in conifer canopies may not be routinely detectable at an operational landscape scale.

Curvature of laser-machined grooves in Si3N4

In laser machining, the article to be machined is moved with respect to the laser beam resulting in the formation of a groove in its surface by vaporization. Grooves formed in hot-pressed Si3N4 with a CO2 laser beam at normal incidence are observed to have cross sections that curve out of the plane defined by the velocity direction of the article and the direction of the laser beam. The curved cross sections change from one side of this plane to the other if the velocity direction is reversed. The effect is most pronounced at the lowest velocities and highest incident powers. The cross-section shape is shown to vary systematically with the angle between the velocity direction and the direction of the electric vector of the incident beam, which was found to be partially polarized. A mechanism for the curved cross-section effect is proposed based on the existence of a significant difference in reflectance between the transverse electric (TE) and transverse magnetic (TM) reflections from groove walls in Si3N4 for large angles of incidence. Calculations of values of reflectance for the TM and TE reflections as a function of the angle of incidence show the existence of a large difference for the CO2 wavelength of 10.6 × 10−4 cm.

Spectra of Normal and Nutrient‐Deficient Maize Leaves1

AbstractSince the advent of spectral mapping and identification of vegetation by remote sensing methods, information about differences in plant nutrient status has gained prominence. Therefore, we decided to study the reflectance, transmittance, and absorptance spectra of “normal” and six types of nutrient‐deficient maize (Zea mays L.) leaves. Nitrogen‐, phosphorus‐, potassium‐, sulfur‐, magnesium‐, and calcium‐deficient leaves were analyzed at 30 selected wavelengths from 500 to 2,600 nm. The analysis of variance showed significant differences in reflectance, transmittance, and absorptance in the visible wavelengths among leaves 3, 4, and 5, among the 7 treatments, and among the interactions of leaf positions and treatments. Only treatments in the infrared wavelengths produced significant differences.The chlorophyll concentration of leaves in all nutrient‐deficiency treatments was lower than that of leaves in the control. Percent moisture in the S‐, Mg‐ and N‐deficiencies was higher. Positive correlations were obtained (r = 0.7) between moisture content and percent absorptance at both 1,450 and 1,930 nm. Second degree polynomial regression analysis of leaf thickness and leaf moisture content showed that these two variables were significantly and directly related (R = 0.894). Leaves from the P‐ and Ca‐deficient plants absorbed less energy than those from normal plants in the near infrared wavelengths; leaves from the S‐, Mg‐, K‐, and N‐deficient plants absorbed more than the normal.Leaf thermograms were prepared on normal and S‐and N‐deficient leaves. Both S‐ and N‐deficient leaves had higher temperatures than normal leaves.