Correlations between spectral and biophysical data obtained in canola canopy cultivated in the subtropical region of Brazil

Abstract: The objective of this work was to identify the spectral bands, vegetation indices, and periods of the canola crop season in which the correlation between spectral data and biophysical indicators (total shoot dry matter and grain yield) is most significant. The experiment was carried out during the 2013 and 2014 crop seasons at Embrapa Trigo, in the state of Rio Grande do Sul, Brazil. A randomized complete block design was used, with four replicates, and the treatments consisted of five doses of nitrogen topdressing. Plant dry matter, grain yield, and phenology were measured. The canola spectral response was evaluated by measuring the canola canopy reflectance using a spectroradiometer, and, with this data, the SR, NDVI, EVI, SAVI, and GNDVI vegetation indices were determined. Pearson’s correlations between the spectral and biophysical variables of canola showed that the red (620 to 670 nm) and near-infrared (841 to 876 nm) bands were the best to estimate the dry matter. The vegetative period is the most indicated to obtain the most significant correlations for canola. All the used vegetation indices are adequate for estimating the dry matter and grain yield of canola.

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Effect of Sunflower Residues and Herbicide on Weed Suppression, Grain Yield and Economics of Transplanted Aman Rice

Bangladesh Agronomy Journal ◽

10.3329/baj.v23i1.50116 ◽

2020 ◽

Vol 23 (1) ◽

pp. 47-58

Author(s):

SS Tanu ◽

P Biswas ◽

S Ahmed ◽

SC Samanta

Keyword(s):

Grain Yield ◽

Dry Matter ◽

Block Design ◽

Weed Suppression ◽

Cost Ratio ◽

Gross Margin ◽

Weed Density ◽

Benefit Cost Ratio ◽

Hand Weeding ◽

Environmentally Sound

A field experiment was conducted at Agronomy Field Laboratory, Patuakhali Science and Technology University, Dumki, Patuakhali from July 2018 to November 2018 to evaluate the effect of sunflower residues and herbicides on the yield and economic performance of transplanted Aman rice. Weed control methods tested were T1 = weedy check (Unweeded control), T2 = Weed-free check by hand weeding twice, T3 = Pendimethalin, T4 = Pretilachlor, T5 = Butachlor, T6 = Pyrazosulfuron ethyl, T7 = Bensulfuron methyl + Acetachlor, T8 = Bispyriback sodium, T9 = 2,4-D amine, T10 = MCPA, T11 = Sunflower residues, T12 = Sunflower residues + 100% Pyrazosulfuron ethyl, T13 = Sunflower residues + 75% Pyrazosulfuron ethyl, T14 = Sunflower residues + 50% Pyrazosulfuron ethyl. The experiment was laid out in a randomized complete block design with fourteen treatments replicated thrice. Weedy check registered significantly the highest total weed density (354.67 m-2) and total weed dry matter (51.81 g-2) while weed-free treatment by hand weeding twice recorded significantly the lowest total weed density (6.67 m-2) and total weed dry matter 0.49 g-2) . Weedy check produced the highest weed index (34.24%) and hand weeding produced the lowest. Among different herbicides applied alone, butachlor had the lowest total weed density (15 m-2) and total weed dry matter (6.43 g-2) after hand weeding. Hand weeding recorded the highest grain yield (5.14 t ha-1) which was statistically similar to pendimethalin, pretilachlor, butachlor, bensulfuron methyl + acetachlor and sunflower residues + 100% pyrazosulfuron ethyl. Higher grain yield was attributed to a higher number of panicle m-2, number of filled grains panicle-1 and 1000-grain weight. The highest gross margin (22955 Tk. ha-1) and benefit-cost ratio (1.32) were obtained from butachlor. Integration of sunflower residues with pyrazosulfuron ethyl produced effective weed suppression and satisfactory yield comparable to butachlor. Although the integration is less profitable than butachlor the farmers can use this technology as a feasible and environmentally sound approach in transplanted Aman rice field. Bangladesh Agron. J. 2020, 23(1): 47-58

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Understanding Vine Hyperspectral Signature through Different Irrigation Plans: A First Step to Monitor Vineyard Water Status

Remote Sensing ◽

10.3390/rs13030536 ◽

2021 ◽

Vol 13 (3) ◽

pp. 536

Author(s):

Eve Laroche-Pinel ◽

Mohanad Albughdadi ◽

Sylvie Duthoit ◽

Véronique Chéret ◽

Jacques Rousseau ◽

...

Keyword(s):

Near Infrared ◽

Water Status ◽

Vegetation Indices ◽

Remote Sensing Data ◽

Short Wave ◽

Spatial And Temporal Scales ◽

Spectral Bands ◽

Main Challenge ◽

Spectral Scale ◽

Grape Varieties

The main challenge encountered by Mediterranean winegrowers is water management. Indeed, with climate change, drought events are becoming more intense each year, dragging the yield down. Moreover, the quality of the vineyards is affected and the level of alcohol increases. Remote sensing data are a potential solution to measure water status in vineyards. However, important questions are still open such as which spectral, spatial, and temporal scales are adapted to achieve the latter. This study aims at using hyperspectral measurements to investigate the spectral scale adapted to measure their water status. The final objective is to find out whether it would be possible to monitor the vine water status with the spectral bands available in multispectral satellites such as Sentinel-2. Four Mediterranean vine plots with three grape varieties and different water status management systems are considered for the analysis. Results show the main significant domains related to vine water status (Short Wave Infrared, Near Infrared, and Red-Edge) and the best vegetation indices that combine these domains. These results give some promising perspectives to monitor vine water status.

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Residual effects of superficial liming on tropical soil under no-tillage system

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2016000900063 ◽

2016 ◽

Vol 51 (9) ◽

pp. 1633-1642 ◽

Cited By ~ 6

Author(s):

Claudio Hideo Martins da Costa ◽

Carlos Alexandre Costa Crusciol ◽

Jayme Ferrari Neto ◽

Gustavo Spadotti Amaral Castro

Keyword(s):

Grain Yield ◽

Dry Matter ◽

Block Design ◽

Residual Effects ◽

Available Phosphorus ◽

Long Term Effects ◽

Matter Production ◽

Randomized Complete Block Design ◽

Tillage System

Abstract The objective of this work was to evaluate the long-term effects of the surface application of lime on soil fertility and on the mineral nutrition and grain yield of soybean, and of black oat and sorghum in crop succession. The experiment was carried out on a clayey Oxisol, in a randomized complete block design, with four replicates. Treatments consisted of lime the rates of 0, 1,000, 2,000, and 4,000 kg ha-1, applied in October 2002 and November 2004. Soil samples were collected at five soil layers, down to 0.60-m depth. Surface liming was effective in reducing soil acidity and increasing Ca2+ and Mg2+ contents in the subsurface. Moreover, it increased available phosphorus contents and soil organic matter in the long term (48 to 60 months after the last lime application). Surface liming improved plant nutrition, mainly for N, Ca, and Mg, and increased dry matter production and grain yield of the crops, even in years with regular distribution of rainfall. The greatest productivities of soybean, black oat, and sorghum were obtained with the respective estimated lime doses of 4,000, 2,333, and 3,281 kg ha-1, for shoot dry matter, and of 2,550, 3,555, and over 4,000 kg ha-1, for grain yield.

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TOPOGRAPHIC EFFECT ON SPECTRAL VEGETATION INDICES FROM LANDSAT TM DATA: IS TOPOGRAPHIC CORRECTION NECESSARY?

Boletim de Ciências Geodésicas ◽

10.1590/s1982-21702016000100006 ◽

2016 ◽

Vol 22 (1) ◽

pp. 95-107 ◽

Cited By ~ 9

Author(s):

Eder Paulo Moreira* ◽

Márcio de Morisson Valeriano ◽

Ieda Del Arco Sanches ◽

Antonio Roberto Formaggio

Keyword(s):

Near Infrared ◽

Incidence Angle ◽

Spectral Band ◽

Vegetation Indices ◽

Topographic Effect ◽

Topographic Correction ◽

Spectral Bands ◽

Spectral Vegetation Indices ◽

Current Availability ◽

Elevation Model

The full potentiality of spectral vegetation indices (VIs) can only be evaluated after removing topographic, atmospheric and soil background effects from radiometric data. Concerning the former effect, the topographic effect was barely investigated in the context of VIs, despite the current availability correction methods and Digital elevation Model (DEM). In this study, we performed topographic correction on Landsat 5 TM spectral bands and evaluated the topographic effect on four VIs: NDVI, RVI, EVI and SAVI. The evaluation was based on analyses of mean and standard deviation of VIs and TM band 4 (near-infrared), and on linear regression analyses between these variables and the cosine of the solar incidence angle on terrain surface (cos i). The results indicated that VIs are less sensitive to topographic effect than the uncorrected spectral band. Among VIs, NDVI and RVI were less sensitive to topographic effect than EVI and SAVI. All VIs showed to be fully independent of topographic effect only after correction. It can be concluded that the topographic correction is required for a consistent reduction of the topographic effect on the VIs from rugged terrain.

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Application of near Infrared Spectroscopy On-Combine in Corn Grain Breeding

Journal of Near Infrared Spectroscopy ◽

10.1255/jnirs.459 ◽

2005 ◽

Vol 13 (2) ◽

pp. 69-75 ◽

Cited By ~ 17

Author(s):

Roland Welle ◽

Willi Greten ◽

Thomas Müller ◽

Gary Weber ◽

Hartwig Wehrmann

Keyword(s):

Grain Yield ◽

Dry Matter ◽

Near Infrared ◽

Reference Method ◽

Nir Spectroscopy ◽

Coefficient Of Determination ◽

Successful Implementation ◽

Grain Moisture ◽

Yield Determination ◽

Corn Grain

Improving maize ( Zea mays L.) grain yield and agronomic properties are major goals for corn breeders in northern Europe. In order to facilitate field grain yield determination we measured corn grain moisture content with near infrared (NIR) spectroscopy directly on a harvesting machine. NIR spectroscopy, in combination with harvesting, significantly improved quality and speed of yield determination within the very narrow harvest time window. Moisture calibrations were developed with 2117 samples from the 2001 to 2003 crop seasons using six diode array spectrometers mounted on combines. These models were derived from databases containing spectra from all instruments. Spectrometer-specific calibrations cannot be used to predict samples measured on other instruments of the same type. Standard error of cross-validation ( SECV) and coefficient of determination ( R2) were 0.56 and 0.99%, respectively. Moisture standard errors of prediction ( SEPs) for the six instruments, using varying independent sample sets from the 2004 harvest, ranged between 0.59% and 0.99% with R2 values between 0.92 to 0.98. The six instruments produced the same dry matter predictions on a common sample set as indicated by high R2 and low biases among them, hence there was no need to apply specific standardisation algorithms. Moisture NIR spectroscopy determinations were significantly more precise than those obtained using the reference method. Analysis of variance revealed low least significant differences and high heritabilities. High precision and heritability demonstrate successful implementation of on-combine NIR spectroscopy for routine dry matter (yield) measurements.

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Simulation and Verification of Vertical Heterogeneity Spectral Response of Winter Wheat Based on the mSCOPE Model

Sensors ◽

10.3390/s20164570 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4570

Author(s):

Linsheng Huang ◽

Yuanyuan Zhang ◽

Guijun Yang ◽

Dong Liang ◽

Heli Li ◽

...

Keyword(s):

Winter Wheat ◽

Vertical Profile ◽

Near Infrared ◽

Spectral Response ◽

Visible Region ◽

Operating Efficiency ◽

Canopy Reflectance ◽

Near Infrared Reflectance ◽

Area Index ◽

Vertical Heterogeneity

Vertical heterogeneity of the biochemical characteristics of crop canopy is important in diagnosing and monitoring nutrition, disease, and crop yield via remote sensing. However, the research on vertical isomerism was not comprehensive. Experiments were carried out from the two levels of simulation and verification to analyze the applicability of this recently development model. Effects of winter wheat on spectrum were studied when input different structure parameters (e.g., leaf area index (LAI)) and physicochemical parameters (e.g., chlorophyll content (Chla+b) and water content (Cw)) to the mSCOPE (Soil Canopy Observation, Photochemistry, and Energy fluxes) model. The maximum operating efficiency was 127.43, when the winter wheat was stratified into three layers. Meanwhile, the simulation results also proved that: the vertical profile of LAI had an influence on canopy reflectance in almost all bands; the vertical profile of Chla+b mainly affected the reflectivity of visible region; the vertical profile of Cw only affected the near-infrared reflectance. The verification results showed that the vegetation indexes (VIs) selected of different bands were strongly correlated with the parameters of the canopy. LAI, Chla+b and Cw affected VIs estimation related to LAI, Chla+b and Cw respectively. The Root Mean Square Error (RMSE) of the new-proposed NDVIgreen was the smallest, which was 0.05. Sensitivity analysis showed that the spectrum was more sensitive to changes in upper layer parameters, which verified the rationality of mSCOPE model in explaining the law that light penetration in vertical nonuniform canopy gradually decreases with the increase of layers.

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Response of Wheat Plants to Combinations of Herbicides with Insecticides and Fungicides

Planta Daninha ◽

10.1590/s0100-83582019370100068 ◽

2019 ◽

Vol 37 ◽

Author(s):

M. VIECELLI ◽

F.B. PAGNONCELLI JR. ◽

M.M. TREZZI ◽

B.M. CAVALHEIRO ◽

R.C.R. GOBETTI

Keyword(s):

Experimental Design ◽

Grain Yield ◽

Yield Components ◽

Dry Matter ◽

Block Design ◽

Wheat Grains ◽

Synergistic Interactions ◽

Randomized Block Design ◽

Relative Tolerance ◽

Chemical Groups

ABSTRACT: The combination of herbicides and other pesticides can influence weed and crop management. This study aimed to evaluate the response of the combination of different herbicides with insecticides or fungicides of different chemical groups on the development and yield of wheat grains of the cultivar ORS Vintecinco. The experimental design was a randomized block design with three replications. The experiment consisted of 33 treatments, as follows: control without application and application of the herbicides 2,4-D (1,005 g a.e. ha-1), bentazon (756 g a.i. ha-1), metsulfuron-methyl (3 g a.i. ha-1), and pyroxsulam (16 g a.i. ha-1), isolated or combined with the insecticides chlorfluazuron (15 g a.i. ha-1), chlorpyrifos (720 g a.i. ha-1), deltamethrin (5 g a.i. ha-1), and methomyl (5 g a.i. ha-1) or with the fungicides azoxystrobin (100 g a.i. ha-1), carbendazim (250 g a.i. ha-1), and propiconazole (190 g a.i. ha-1). Relative tolerance (RT), shoot dry matter (SDM), yield components, and grain yield were evaluated. In general, pyroxsulam had the highest number of synergistic interactions with insecticides and fungicides, reducing RT and SDM, especially the combination pyroxsulam + chlorpyrifos due to a lower RT level (45%) and higher SDM reduction (52%). All combinations of herbicides with the insecticide chlorpyrifos and most of the combinations with the fungicide propiconazole led to a reduction of grain yield when compared to their isolated application or to control without application.

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Role of salicylic acid as foliar spray on hydride rice (BRRI Hybrid dhan3) cultivation in Bangladesh

Research in Agriculture Livestock and Fisheries ◽

10.3329/ralf.v4i3.35092 ◽

2017 ◽

Vol 4 (3) ◽

pp. 157-164

Author(s):

Mohammad Issak ◽

Most Moslama Khatun ◽

Amena Sultana

Keyword(s):

Salicylic Acid ◽

Grain Yield ◽

Biomass Production ◽

Dry Matter ◽

Foliar Application ◽

Block Design ◽

Foliar Spray ◽

Dry Matter Production ◽

Control Treatment ◽

Matter Production

The experiment was conducted to study the effect of salicylic acid (SA) as foliar spray on yield and yield contributing characters of BRRI Hybrid dhan3.The experiment was laid out in a randomized complete block design (RCBD) with three replications and six treatment combinations as, T1: 0 μM SA, T2: 200 μM SA, T3: 400 μM SA, T4: 600 μM SA, T5: 800 μM SA and T6: 1000 μM SA. The results revealed that biomass production, dry matter production and yield and yield contributing characters were significantly increased due to the foliar application of SA. At the maximum tillering (MT) stage, the highest biomass production (15.0 t/ha) and dry matter production was observed in T3 treatment. Treatments T4, T5 and T6 showed significant variation on the effective tillers/hill. The maximum effective tillers/hill were found in the treatment T6. The percentages of spikelet sterility were decreased with increasing the level of SA and the percentage of filled grains/panicle were increased with increasing level of SA. The insect infestation was reduced with increasing level of SA to up to 1000 μM. The maximum grain yield (9.21 t/ha) and straw yield (9.22 t/ha) was found in the treatment T6 which was identical to T5. On the other hand, in all cases the lowest results were found in the control treatment. The result showed that grain yield of rice increased with increasing level of SA to up to 1000 μM (T6 treatment). Our results suggest that foliar spray of SA might be applied to increase the yield of hybrid rice in Bangladesh.Res. Agric., Livest. Fish.4(3): 157-164, December 2017

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Yield, nutritional quality and stability of orangefleshed sweetpotato cultivars successively later harvesting periods in Mozambique

Open Agriculture ◽

10.1515/opag-2017-0050 ◽

2017 ◽

Vol 2 (1) ◽

Cited By ~ 3

Author(s):

Abilio Alvaro ◽

Maria I. Andrade ◽

Godwill S. Makunde ◽

Fishua Dango ◽

Omowumi Idowu ◽

...

Keyword(s):

Dry Matter ◽

Near Infrared ◽

Smallholder Farmers ◽

Block Design ◽

Beta Carotene ◽

Infrared Spectrometry ◽

Long Term Storage ◽

First Time ◽

Weevil Infestation

AbstractLong-term storage of sweetpotato roots is a great challenge for smallholder farmers in Mozambique. Piecemeal harvesting allows several months supply of roots for household consumption provided weevil infestation is avoided. The objectives of the present studies were to determine yield and changes in key macro- and micronutrients associated with early or late harvesting of orange-fleshed sweetpotato cultivars in Mozambique. Four trials representing harvesting periods of 3, 4, 5 or 6 months after planting were established at Gurue in 2015. The randomized complete block design with three replications was laid in each trial. Yield measurements were done in the field and samples were selected and scanned for dry matter, beta-carotene, iron, zinc and carbohydrate using Near Infrared Spectrometry. Collected data were statistically analysed (SAS 1997 software). Yield, dry matter, starch, iron and beta-carotene increased linearly in some cultivars as time to harvest was prolonged. Iron was not affected by harvesting period. Stability of micronutrients such as iron, zinc and beta-carotene is essential when piecemeal harvesting. The study allowed accurate grouping of the cultivars tested into maturity groups for the first time.

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Use of Abattoir Wastewater Compost as Organic Fertilizer for Rice Production on a Ultisol in Delta State, Nigeria

Asian Journal of Agriculture and Rural Development ◽

10.18488/journal.ajard.2020.102.682.689 ◽

2020 ◽

Vol 10 (2) ◽

pp. 682-689

Author(s):

Smart Augustine Ojobor ◽

Collins N Egbuchua

Keyword(s):

Grain Yield ◽

Dry Matter ◽

Block Design ◽

Organic Fertilizer ◽

Growth And Yield ◽

Residual Effects ◽

First Year ◽

Rice Yields ◽

Abattoir Wastewater ◽

Nutrient Changes

The research was conducted to monitor the influent of abattoir wastewater compost on rice growth and yield in Benin-Owah River Basin in Illah, Delta State, Nigeria. The compost was applied at 0, 2.5, 5.0, 10 t/ha, and NPK15:15:15 at 250 kg/ha laid in randomized complete block design with four replicates. Rice seeds were sown for two years, and residual effects were evaluated in the third year. Rice plant height, stem circumference, and the number of tillers was measured at two weeks intervals while rice yields have taken at harvest. Soil samples were taken yearly to monitor nutrient changes. Data obtained were analyzed with analysis of variance and mean separated with Duncan Multiple Range Test at α0.05. In the first year, NPK15:15:15 significantly gave the highest dry matter (6.28±1.45 t/ha) and grain yield (2.4±0.53 t/ha). While in the second year, 10 t/ha treatment produced the dry matter (7.69±1.60 t/ha) and grain yield (2.6±0.53 t/ha). In a residual study, the highest grain yield (2.8±0.72 t/ha) was produced in the plot treated with 10 t/ha, and it also gave the highest pH, organic carbon, total nitrogen, and available P content. The compost at the rate of 10 t/ha can increase soil fertility and rice yield.

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