Sensitivity of sensor-based nitrogen rates to selection of within-field calibration strips in winter wheat

2017 ◽  
Vol 68 (2) ◽  
pp. 101 ◽  
Author(s):  
Stanisław M. Samborski ◽  
Dariusz Gozdowski ◽  
Olga S. Walsh ◽  
Peter Kyveryga ◽  
Michał Stłpieł
Keyword(s):  
Winter Wheat ◽  
Optical Sensors ◽  
Representative Sample ◽  
Stem Elongation ◽  
Triticum Aestivum L ◽  
Canopy Reflectance ◽  
Sample Strip ◽  
Vegetative Indices ◽  
N Status ◽  
Selection Of

Active optical sensors (AOSs) are used for in-season variable-rate application of nitrogen (N). The sensors measure crop reflectance expressed as vegetative indices (VIs). These are transformed into N recommendations during on-site calibration of AOSs—‘familiarising’ the sensors with the crop N status of the representative part of a field. The ‘drive-first’ method is often used by growers to calibrate AOSs. Due to large spatial variation of crop N status within fields, it is difficult to identify the most representative sample strip for AOS calibration. Seven site-years were used to evaluate the sensitivity of sensor-based N prescriptions for winter wheat (Triticum aestivum L.) to selection of sample strips for AOS calibration that fall into extreme, very low or very high values of 95th percentiles of amber normalised difference VI (NDVI) values. A Crop Circle ACS-210 sensor was used to collect canopy reflectance values, expressed as amber NDVI, at the beginning of wheat stem elongation. Our study showed that the sample-strip selection significantly affected sensor-based N prescriptions. The drive-first method may result in under- or over-applications of N and in lower N-use efficiency. One way to overcome this problem is to collect whole field NDVI values during pesticide application before sensor-based N application. The NDVI values from the entire field then can be used to choose the most representative sample strips for AOS calibration.

scholarly journals Evaluating Two Crop Circle Active Canopy Sensors for In-Season Diagnosis of Winter Wheat Nitrogen Status

Agronomy ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 201 ◽  
Author(s):  
Qiang Cao ◽  
Yuxin Miao ◽  
Jianning Shen ◽  
Fei Yuan ◽  
Shanshan Cheng ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Vegetation Indices ◽  
Field Measurements ◽  
Triticum Aestivum L ◽  
Coefficient Of Determination ◽  
Growth Stages ◽  
Canopy Reflectance ◽  
Red Edge ◽  
N Management ◽  
N Status

Active crop canopy sensors can be used for non-destructive real-time diagnosis of crop nitrogen (N) status and guiding in-season N management. However, limited studies have compared the performances of two commercially available sensors with three different wavebands: Crop Circle ACS-470 (CC-470) and Crop Circle ACS-430 (CC-430). The objective of this study was to evaluate the performances of CC-470 and CC-430 sensors for estimating winter wheat (Triticum aestivum L.) N status at different measurement heights (40 cm, 70 cm and 100 cm) and growth stages. Results indicated that the canopy reflectance values of CC-470 were more affected by height compared to the CC-430 sensor. The normalized difference red edge (NDRE) and red edge chlorophyll index (CIRE) of CC-430 were stable at the three different measuring heights. The relationships between these indices and the N status indicators were stronger at the Feekes 9–10 stages than the Feekes 6–7 stages for both sensors; however, the CC-430 sensor-based vegetation indices had higher coefficient of determination (R2) values for both stages. It is concluded that the CC-430 sensor is more reliable than CC-470 for winter wheat N status estimation due to its capability of making height-independent measurements. These results demonstrated the importance of considering the influences of height when using active canopy sensors in field measurements.

scholarly journals Evaluation of Three Portable Optical Sensors for Non-Destructive Diagnosis of Nitrogen Status in Winter Wheat

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5579
Author(s):  
Jie Jiang ◽  
Cuicun Wang ◽  
Hui Wang ◽  
Zhaopeng Fu ◽  
Qiang Cao ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Optical Sensors ◽  
Accurate Estimation ◽  
Growth Stages ◽  
N Accumulation ◽  
N Nutrition ◽  
N Concentration ◽  
Non Destructive ◽  
N Status ◽  
Leaf N

The accurate estimation and timely diagnosis of crop nitrogen (N) status can facilitate in-season fertilizer management. In order to evaluate the performance of three leaf and canopy optical sensors in non-destructively diagnosing winter wheat N status, three experiments using seven wheat cultivars and multi-N-treatments (0–360 kg N ha−1) were conducted in the Jiangsu province of China from 2015 to 2018. Two leaf sensors (SPAD 502, Dualex 4 Scientific+) and one canopy sensor (RapidSCAN CS-45) were used to obtain leaf and canopy spectral data, respectively, during the main growth period. Five N indicators (leaf N concentration (LNC), leaf N accumulation (LNA), plant N concentration (PNC), plant N accumulation (PNA), and N nutrition index (NNI)) were measured synchronously. The relationships between the six sensor-based indices (leaf level: SPAD, Chl, Flav, NBI, canopy level: NDRE, NDVI) and five N parameters were established at each growth stages. The results showed that the Dualex-based NBI performed relatively well among four leaf-sensor indices, while NDRE of RS sensor achieved a best performance due to larger sampling area of canopy sensor for five N indicators estimation across different growth stages. The areal agreement of the NNI diagnosis models ranged from 0.54 to 0.71 for SPAD, 0.66 to 0.84 for NBI, and 0.72 to 0.86 for NDRE, and the kappa coefficient ranged from 0.30 to 0.52 for SPAD, 0.42 to 0.72 for NBI, and 0.53 to 0.75 for NDRE across all growth stages. Overall, these results reveal the potential of sensor-based diagnosis models for the rapid and non-destructive diagnosis of N status.

scholarly journals Epigenetic in heritance and selection of heat and frost resistant wheat (Triticum aestivum L.) Genotypes

2021 ◽  
Author(s):  
Natalia Jelev ◽  
◽  
Nina Zdioruk ◽  
Alexandru Dascaliuc ◽  
Iaroslav Parii ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Heat Shock ◽  
Winter Wheat ◽  
Correlation Coefficient ◽  
Triticum Aestivum L ◽  
Extreme Temperatures ◽  
Primary Resistance ◽  
Wheat Genotypes ◽  
Negative Temperatures ◽  
Selection Of

The primary resistance and plasticity of the response to shock with negative temperatures (SNT) or heat shock (HS) of different winter wheat genotypes grown in Ukraine and then reproduced in Moldo-va are determined. The values of the mentioned parameters specifically varied depended on the genotype specificity and conditions of seeds reproduction. Thus, data support the hypothesis about the specificity of trans-generational inheritance of wheat genotypes adaptations to extreme temperatures. Furthermore, the correlation coefficient between the resistance SNT value to HS and inversed value (HS/SNT) ratio may indicate the epigenetically inherited effects.

scholarly journals PR-proteins as markers of winter wheat (Triticum aestivum L.) resistance to leaf pathogens

2019 ◽  
Vol 64 (3) ◽  
pp. 286-291 ◽  
Author(s):  
Y. V. Viazau ◽  
M. S. Radyuk ◽  
E. A. Filipchik ◽  
N. V. Shalygo
Keyword(s):  
Winter Wheat ◽  
Lipid Transfer Protein ◽  
Constitutive Expression ◽  
Triticum Aestivum L ◽  
Pcr Analysis ◽  
Lipid Transfer ◽  
Transfer Protein ◽  
Resistant Varieties ◽  
Genes Encoding ◽  
Selection Of

Using real-time PCR analysis, the constitutive expression of PR-protein genes encoding thaumatin-like protein (TLP), peroxidase III (TaPero), chitinase (Chitin), glucanase (Glucan), protease inhibitor (PrInh), oxalate oxidase (OxOxid) and lipid transfer protein (Ltp) was studied in collection varieties of winter wheat. It has been shown that plants of varieties with increased resistance to a complex of leaf pathogens have higher constitutive expression levels of Chitin and PrInh genes, and, to a greater extent, of TLP, TaPero and Glucan genes, compared with non-resistant varieties. It is proposed to use constitutive levels of expression of TLP, TaPero and Glucan genes for the selection of winter wheat varietal samples with increased resistance to the complex of leaf diseases.

scholarly journals Ecological and Geographical Selection of Winter Wheat (Triticum aestivum L.) in Kazakhstan and Kyrgyzstan

2009 ◽  
Vol 0 (1(9)) ◽  
pp. 102-113
Author(s):  
Р. А. Уразалієв ◽  
М. К. Джунусова ◽  
А. С. Жангазієв ◽  
А. Є. Джатканбаєва
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Triticum Aestivum L ◽  
Selection Of

scholarly journals Comparison of the Androgenic Response of Spring and Winter Wheat (Triticum aestivum L.)

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 49 ◽  
Author(s):  
Dorota Weigt ◽  
Angelika Kiel ◽  
Idzi Siatkowski ◽  
Joanna Zyprych-Walczak ◽  
Agnieszka Tomkowiak ◽  
...  
Keyword(s):  
Plant Regeneration ◽  
Winter Wheat ◽  
Spring Wheat ◽  
Triticum Aestivum L ◽  
Green Plant ◽  
Medium Composition ◽  
Growth Hormones ◽  
Induction Medium ◽  
Breeding Programmes ◽  
Selection Of

Androgenesis is potentially the most effective technique for doubled haploid production of wheat. It is not however widely used in breeding programmes due to its main limitation: the genotype dependence. Due to genetic differences between spring and winter wheat, it was assumed that both phenotypes are different in their capacity to conduct androgenesis. And so, the aim of this investigation was to verify the effectiveness of androgenesis induction and plant regeneration of spring and winter wheat genotypes while considering varying amounts of growth hormones in the induction medium. Fifteen genotypes of spring wheat and fifteen of winter wheat were used in the experiment. Six hundred anthers of each of the 30 genotypes were plated and analysed. Previous studies have allowed selection of the best medium for wheat androgenesis and a combination of growth hormones that are the most effective in stimulating microspore proliferation. Therefore, C17 induction media with two combinations of growth hormones were used: I—supplemented only by auxins (2,4-D and dicamba), and II—supplemented by auxin and cytokinin (2,4-D and kinetin). Data was recorded according to the efficiency of androgenic structure formation (ASF), green plant regeneration (GPR), and albino plant regeneration (APR). The results showed that the induction and regeneration of androgenesis in the spring wheat were more efficient than in the winter ones. The spring genotypes formed more androgenic structures and green plants on anthers plated on the medium supplemented only by auxins, in contrast to the winter genotypes which were better induced and regenerated on the medium supplemented by auxin and cytokinin. The study showed that to increase the efficiency of androgenesis, it is necessary to select appropriate factors such as concentration and type of hormones in medium composition, affecting the course of the culturing procedure according to the winter or spring phenotype of donor plants.

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