Phenotyping Conservation Agriculture Management Effects on Ground and Aerial Remote Sensing Assessments of Maize Hybrids Performance in Zimbabwe
"> Figure 1
<p>Landsat satellite (<b>left</b>) and CNES Airbus (<b>right</b>) images of the study area acquired using Google Earth Pro. The photographs are from the 31st of December 2015. The image on the left shows the location of the Domboshawa Training Center in Zimbabwe. The image on the right shows the field site.</p> "> Figure 2
<p>Map of the experimental design showing alternating High Density (HD) and Low Density (LD) plots per replicate, with Conservation Agriculture (CA) on the left and Conventional Ploughing (CP) on the right. Each square corresponds one plot dedicated to each of the different hybrids used. Complete details of the experimental design are explained in <a href="#sec2dot2-remotesensing-10-00349" class="html-sec">Section 2.2</a>.</p> "> Figure 3
<p>Mikrokopter OktoXL 6S12 unmanned aerial platform equipped with the micro-MCA12 Tetracam multispectral sensor, showing the placement of the Incident Light Sensor (ILS) module with white diffusor plate connected by a fiber optic cable to the top of the UAV facing upwards while the other 11 multispectral sensors are positioned on a dual axis gimbal camera platform for zenithal/nadir image capture. The RGB (Red-Green-Blue) and TIR (thermal infrared) cameras were alternately mounted on the same gimbaled platform for image capture.</p> "> Figure 4
<p>Relationship between grain yield with the Normalized Difference Vegetation Index (NDVI), measured with the GreenSeeker and calculated from the aerial multispectral images (<b>a</b>,<b>b</b>) and with the Photochemical Reflectance Index (PRI), measured from the aerial multispectral images (<b>c</b>,<b>d</b>).</p> "> Figure 5
<p>Examples of the differences in the vegetation area identification with the RGB and multispectral images with at the conservation (ca) and conventional (CP) plots.</p> ">
Abstract
:1. Introduction
2. Materials and Methods
2.1. Site Description
2.2. Plant Materials and Experimental Design
2.3. Agronomical Traits and Proximal (Ground) Data Collection
2.4. Aerial Data Collection
2.5. Carbon and Nitrogen Stable Isotope Compositions
2.6. Statistical Analysis
3. Results
3.1. Differences in Yield Parameters and Conventional Phenotyping Measurements within Growing Conditions and Genotypes
3.2. The Effect of Conservation and Conventional Agricultural Practices and the Sensor Altitude on Vegetation Indexes
3.3. Performance of Remote Sensing Index as Predictors of Grain Yield
4. Discussion
4.1. Implications of Growing Conditions on Yield Parameters
4.2. Comparative Performance of the Vegetation Indexes at Determining Differences in Grain Yield under CP and CA Conditions
4.3. Platform Proximity Effects on the Performance of the Vegetation Indexes Assessing Grain Yield Differences
5. Conclusions
Supplementary Materials
Acknowledgments
Author Contributions
Conflicts of Interest
Abbreviations
SSA | Sub-Saharan Africa |
RGB | Red-Blue-Green |
CA | conservation agriculture |
CP | conventional ploughed |
NDVI | Normalized Difference Vegetation Index |
UAV | unmanned aerial vehicle |
GY | grain yield |
HIS | Hue-Intensity-Saturation |
GA | Green Area |
GGA | Greener Area |
CSI | Crop Senescense Index |
CIMMYT | International Maize and Wheat Improvement Center |
m.a.s.l. | meters above sea level |
CP-OES | Inductively Coupled Plasma Optical Emission Spectroscopy |
LCC | leaf chlorophyll content |
PRI | Photochemical Reflectance Index |
SAVI | Soil Adjusted Vegetation Index |
MCARI | Modified Chlorophyll Absorption Ratio Index |
WBI | Water Band Index |
RDVI | Renormalized Difference Vegetation Index |
EVI | Enhanced Vegetation Index |
ARI2 | Anthocyanin Reflectance Index 2 |
CRI2 | Carotenoid Reflectance Index 2 |
TCARI | Transformed Chlorophyll Absorption in Reflectance Index |
OSAVI | Optimized Soil-Adjusted Vegetation Index |
ΔF/Fm’ | Effective fluorescence quantum yield |
NIR | near-infrared. |
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Group | Index | Equation | Wavelengths | References |
---|---|---|---|---|
Broadband Greenness | Normalized Difference Vegetation Index (NDVI) | Red, NIR | [35] | |
Soil Adjusted Vegetation Index (SAVI) | Intermediate vegetation, L = 0.5 | Red, NIR | [36] | |
Optimized soil-adjusted vegetation index (OSAVI) | Red, NIR | [37] | ||
Renormalized Difference Vegetation Index (RDVI) | Red, NIR | [38] | ||
Enhanced Vegetation Index (EVI) | Blue, Red, NIR | [39] | ||
Light Use Efficiency | Photochemical Reflectance Index (PRI) * | Green | [40] | |
Leaf Pigments | Modified Chlorophyll Absorption Ratio Index (MCARI) | Green, Red, NIR | [41] | |
Chlorophyll Content Index (CCI) | Green, NIR | [42] | ||
Transformed Chlorophyll Absorption Ratio Index (TCARI) | Green, Red, NIR | [43] | ||
Green, Red, NIR | ||||
Anthocyanin Reflectance Index 2 (ARI2) | Blue, Red, NIR | [44] | ||
Carotenoid Reflectance Index 2 (CRI2) | Blue, Red | [45] | ||
Water Content | Water Band Index (WBI) | Red, NIR | [46] |
GY | Biomass | Harvest Index | SPAD | Temperature | C | δ13C | N | δ15N | C/N | |
---|---|---|---|---|---|---|---|---|---|---|
(Mg ha−1) | (Mg ha−1) | (°C) | (%) | (‰) | (%) | (‰) | ||||
Treatment | ||||||||||
CA | 2.99 ± 0.10 | 2.66 ± 0.11 | 0.49 ± 0.01 | 42.71 ± 0.38 | 25.02 ± 0.10 | 45.8 ± 0.50 | −11.98 ± 0.03 | 3.77 ± 0.04 | 0.52 ± 0.08 | 12.14 ± 0.06 |
CP | 2.42 ± 0.14 | 2.50 ± 0.14 | 0.44 ± 0.01 | 42.24 ± 0.38 | 24.64 ± 0.15 | 44.64 ± 0.49 | −11.93 ± 0.03 | 3.69 ± 0.04 | 0.59 ± 0.07 | 12.11 ± 0.05 |
p-value | 0.000 *** | 0.351 | 0.000 *** | 0.395 | 0.017 * | 0.097 | 0.287 | 0.161 | 0.518 | 0.673 |
Density | ||||||||||
LD | 2.61 ± 0.12 | 2.45 ± 0.12 | 0.47 ± 0.01 | 42.37 ± 0.36 | 24.59 ± 0.12 | 45.32 ± 0.58 | −11.95 ± 0.03 | 3.74 ± 0.05 | 0.51 ± 0.07 | 12.13 ± 0.05 |
HD | 2.81 ± 0.13 | 2.71 ± 0.13 | 0.46 ± 0.01 | 42.45 ± 0.40 | 25.14 ± 0.11 | 45.08 ± 0.41 | −11.96 ± 0.03 | 3.72 ± 0.04 | 0.59 ± 0.08 | 12.12 ± 0.06 |
p-value | 0.230 | 0.145 | 0.820 | 0.712 | 0.000 *** | 0.724 | 0.922 | 0.760 | 0.453 | 0.988 |
Combinations | ||||||||||
CA * LD | 2.92 ± 0.13 | 2.59 ± 0.17 | 0.49 ± 0.01 | 42.61 ± 0.56 | 24.80 ± 0.13 | 46.64 ± 0.48 | −11.97 ± 0.04 | 3.83 ± 0.04 | 0.53 ± 0.11 | 12.18 ± 0.07 |
CA * HD | 3.07 ± 0.14 | 2.73 ± 0.15 | 0.49 ± 0.01 | 42.81 ± 0.52 | 24.32 ± 0.21 | 44.99 ± 0.85 | −11.98 ± 0.04 | 3.72 ± 0.07 | 0.50 ± 0.12 | 12.10 ± 0.09 |
CP * LD | 2.29 ± 0.19 | 2.31 ± 0.18 | 0.44 ± 0.01 | 42.14 ± 0.47 | 25.25 ± 0.13 | 44.1 ± 0.97 | −11.94 ± 0.04 | 3.66 ± 0.08 | 0.49 ± 0.09 | 12.07 ± 0.08 |
CP * HD | 2.55 ± 0.20 | 2.69 ± 0.21 | 0.44 ± 0.01 | 42.34 ± 0.61 | 24.99 ± 0.17 | 45.18 ± 0.08 | −11.93 ± 0.05 | 3.72 ± 0.02 | 0.68 ± 0.11 | 12.14 ± 0.07 |
p-value | 0.751 | 0.484 | 0.931 | 0.999 | 0.489 | 0.051 | 0.812 | 0.146 | 0.312 | 0.353 |
CA | CP | LD | HD | |
---|---|---|---|---|
SC513 | 2.50 ± 0.18 | 1.52 ± 0.19 | 2.12 ± 0.34 | 1.90 ± 0.20 |
SC621 | 2.32 ± 0.18 | 2.60 ± 0.39 | 2.54 ± 0.19 | 2.38 ± 0.40 |
PAN53 | 3.26 ± 0.13 | 2.71 ± 0.36 | 2.82 ± 0.23 | 3.16 ± 0.33 |
30G19 | 2.52 ± 0.15 | 2.12 ± 0.34 | 2.22 ± 0.26 | 2.42 ± 0.29 |
Zap55 | 3.72 ± 0.18 | 3.03 ± 0.39 | 3.23 ± 0.36 | 3.52 ± 0.31 |
Pristine 601 | 3.16 ± 0.26 | 2.02 ± 0.37 | 2.19 ± 0.39 | 2.98 ± 0.34 |
PGS61 | 3.23 ± 0.25 | 2.61 ± 0.29 | 2.76 ± 0.25 | 3.07 ± 0.34 |
Zap61 | 3.24 ± 0.29 | 2.74 ± 0.53 | 2.95 ± 0.51 | 3.03 ± 0.35 |
p-value | 0.001 ** | 0.147 | 0.155 | 0.007 ** |
Intensity | Hue | Saturation | Lightness | a* | b* | u* | v* | GA | GGA | CSI | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Ground | CA | 0.37 ± 0.00 | 48.04 ± 0.97 | 0.19 ± 0.00 | 44.01 ± 0.23 | −4.44 ± 0.28 | 20.14 ± 0.35 | 3.59 ± 0.42 | 22.91 ± 0.36 | 0.26 ± 0.01 | 0.24 ± 0.01 | 8.83 ± 0.60 |
CP | 0.36 ± 0.00 | 39.96 ± 0.91 | 0.25 ± 0.00 | 42.81 ± 0.19 | −1.27 ± 0.38 | 23.13 ± 0.24 | 9.12 ± 0.57 | 24.79 ± 0.21 | 0.19 ± 0.01 | 0.18 ± 0.01 | 6.48 ± 0.46 | |
p-value | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.002 *** | |
Aerial | CA | 0.49 ± 0.00 | 38.25 ± 0.75 | 0.19 ± 0.00 | 54.96 ± 0.35 | −0.54 ± 0.32 | 24.21 ± 0.13 | 11.67 ± 0.54 | 28.10 ± 0.14 | 0.22 ± 0.01 | 0.15 ± 0.01 | 32.87 ± 1.19 |
CP | 0.49 ± 0.00 | 31.38 ± 0.49 | 0.25 ± 0.00 | 55.25 ± 0.48 | 4.99 ± 0.39 | 28.77 ± 0.27 | 22.2 ± 0.76 | 31.34 ± 0.27 | 0.16 ± 0.01 | 0.10 ± 0.01 | 42.43 ± 2.41 | |
p-value | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** |
Vegetation | NDVI.g | NDVI | SAVI | OSAVI | RDVI | EVI | PRI | MCARI | CCI | ||
---|---|---|---|---|---|---|---|---|---|---|---|
Plot | CA | 66.25 ± 0.93 | 0.55 ± 0.01 | 0.42 ± 0.01 | 0.27 ± 0.01 | 0.34 ± 0.01 | 4.19 ± 0.10 | 0.54 ± 0.01 | 0.16 ± 0.00 | 19.54 ± 0.47 | 0.08 ± 0.01 |
CP | 72.30 ± 1.04 | 0.48 ± 0.01 | 0.38 ± 0.01 | 0.25 ± 0.01 | 0.31 ± 0.01 | 3.85 ± 0.11 | 0.39 ± 0.01 | 0.13 ± 0.00 | 16.89 ± 0.38 | −0.01 ± 0.01 | |
p-value | 0.000 *** | 0.000 *** | 0.006 ** | 0.031 * | 0.013 * | 0.026 * | 0.000 *** | 0.000 *** | 0.000 *** | 0.000 *** | |
Vegetation | CA | 0.66 ± 0.01 | 0.45 ± 0.01 | 0.55 ± 0.01 | 6.85 ± 0.11 | 0.88 ± 0.02 | 0.21 ± 0.00 | 32.16 ± 0.66 | 0.27 ± 0.01 | ||
CP | 0.62 ± 0.01 | 0.44 ± 0.01 | 0.53 ± 0.01 | 6.68 ± 0.11 | 0.74 ± 0.01 | 0.19 ± 0.00 | 31.74 ± 0.61 | 0.20 ± 0.01 | |||
p-value | 0.001 ** | 0.343 | 0.049 * | 0.263 | 0.000 *** | 0.000 *** | 0.624 | 0.000 *** | |||
TCARI | TCARI/OSAVI | ARI2 | CRI2 | WBI | |||||||
Plot | CA | 36.40 ± 0.67 | 0.42 ± 0.01 | 0.47 ± 0.01 | 0.01 ± 0.00 | 0.94 ± 0.01 | |||||
CP | 35.68 ± 0.74 | 0.47 ± 0.02 | 0.73 ± 0.01 | 0.01 ± 0.00 | 0.93 ± 0.00 | ||||||
p-value | 0.461 | 0.030 * | 0.000 *** | 0.000 *** | 0.558 | ||||||
Vegetation | CA | 46.75 ± 0.82 | 0.33 ± 0.01 | 0.23 ± 0.02 | 0.00 ± 0.00 | 1.01 ± 0.01 | |||||
CP | 50.15 ± 1.10 | 0.38 ± 0.01 | 0.51 ± 0.02 | 0.01 ± 0.00 | 0.99 ± 0.00 | ||||||
p-value | 0.012 * | 0.001 ** | 0.000 *** | 0.000 *** | 0.06 |
Intensity | Hue | Saturation | Lightness | a* | b* | u* | v* | GA | GGA | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Ground measurements | Tillage | |||||||||||
CA | −0.065 | 0.484 *** | −0.317 * | −0.021 | −0.509 * | −0.226 | −0.544 *** | −0.137 | 0.487 *** | 0.507 *** | ||
CP | 0.503 *** | 0.741 *** | −0.478 *** | 0.568 *** | −0.742 *** | −0.206 | −0.717 *** | 0.157 | 0.777 *** | 0.783 *** | ||
Planting density | ||||||||||||
LD | 0.342 * | 0.597 *** | −0.483 *** | 0.366 * | −0.633 *** | −0.350 * | −0.623 *** | −0.152 | 0.660 *** | 0.662 *** | ||
HD | 0.361 * | 0.754 *** | −0.509 *** | 0.410 ** | −0.785 *** | −0.326 * | −0.771 *** | −0.100 | 0.767 *** | 0.767 *** | ||
Combinations | ||||||||||||
CA * LD | −0.054 | 0.422 * | −0.386 | −0.032 | −0.498 * | −0.310 | −0.539 ** | −0.213 | 0.511* | 0.513 * | ||
CA * HD | −0.054 | 0.580 ** | −0.247 | 0.020 | −0.570 ** | −0.138 | −0.585 ** | −0.052 | 0.493 * | 0.528 ** | ||
CP * LD | 0.419 * | 0.622 | −0.304 | 0.456 * | −0.596 ** | −0.032 | −0.567 ** | 0.218 | 0.627 ** | 0.636 *** | ||
CP * HD | 0.565 ** | 0.827 *** | −0.594 ** | 0.671 *** | −0.850 *** | −0.318 | 0.830 *** | 0.176 | 0.894 *** | 0.898 *** | ||
Aerial mesurements | Tillage | |||||||||||
CA | −0.393 ** | 0.548 *** | −0.149 | −0.363 * | −0.567 *** | −0.265 | −0.554 * | −0.145 | 0.562 *** | 0.561 *** | ||
CP | −0.776 *** | 0.754 *** | −0.719 *** | −0.777 *** | −0.796 *** | −0.818 *** | −0.812 *** | −0.794 *** | 0.784 *** | 0.798 *** | ||
Planting density | ||||||||||||
LD | −0.555 *** | 0.614 *** | −0.495 *** | −0.565 *** | −0.651 *** | −0.606 *** | −0.658 *** | −0.617 *** | 0.653 *** | 0.664 *** | ||
HD | −0.627 *** | 0.684 *** | −0.440 ** | −0.631 *** | −0.739 *** | −0.667 *** | −0.751 *** | −0.697 *** | 0.776 *** | 0.786 *** | ||
Combinations | ||||||||||||
CA* LD | −0.468 * | 0.582 ** | −0.292 | −0.444 * | −0.600 ** | −0.395 | −0.594 ** | −0.296 | 0.578 ** | 0.572 ** | ||
CA * HD | −0.360 | 0.519 ** | −0.105 | −0.331 | −0.544 ** | −0.262 | −0.533 ** | −0.116 | 0.545 ** | 0.557 ** | ||
CP * LD | −0.606 ** | 0.577 ** | −0.649 *** | −0.610 ** | −0.654 *** | −0.694 *** | −0.674 *** | −0.662 *** | −0.662 ** | 0.633 *** | ||
CP * HD | −0.907 *** | 0.881 *** | −0.793 *** | −0.906 *** | −0.900 *** | −0.920 *** | −0.913 *** | −0.905 *** | 0.916 *** | 0.920 *** |
Vegetation area | NDVI.g | NDVI | SAVI | OSAVI | RDVI | EVI | PRI | MCARI | CCI | TCARI | TCARI/OSAVI | ARI2 | CRI2 | WBI | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Plot measurements | Tillage | ||||||||||||||||
CA | −0.386 ** | 0.490 ** | 0.361 * | 0.389 ** | 0.379 ** | 0.390 ** | 0.368 * | 0.435 ** | 0.215 | 0.355 * | 0.094 | −0.334 * | −0.321 | −0.299 * | 0.116 | ||
CP | −0.727 *** | 0.812 *** | 0.751 *** | 0.729 *** | 0.747 *** | 0.734 *** | 0.676 *** | 0.697 *** | 0.105 | 0.710 *** | −0.454 ** | −0.785 | −0.479 | 0.066 | 0.412 ** | ||
Planting density | |||||||||||||||||
LD | −0.592 *** | 0.740 ** | 0.577 *** | 0.477 *** | 0.532 *** | 0.493 *** | 0.488 *** | 0.641 *** | 0.127 | 0.610 *** | −0.253 | −0.671 *** | −0.549 *** | −0.372 * | 0.269 | ||
HD | −0.737 *** | 0.795 ** | 0.750 *** | 0.748 *** | 0.753 *** | 0.749 *** | 0.714 *** | 0.713 *** | 0.495 *** | 0.731 * | −0.285 | −0.755 *** | −0.500 *** | −0.26 | 0.364 * | ||
Combinations | |||||||||||||||||
CA * LD | −0.38 | 0.464 * | 0.298 | 0.281 | 0.289 | 0.285 | 0.251 | 0.398 | 0.108 | 0.327 | 0.006 | −0.379 | −0.483 * | −0.359 | 0.065 | ||
CA * HD | −0.393 | 0.526 * | 0.402 | 0.481 * | 0.444 * | 0.475 * | 0.528 * | 0.473 * | 0.415 | 0.397 * | 0.143 | −0.367 | −0.263 | −0.19 | 0.284 | ||
CP * LD | −0.602 ** | 0.793 ** | 0.630 *** | 0.582 ** | 0.614 ** | 0.590 ** | 0.490 ** | 0.617 ** | −0.079 | 0.589 ** | −0.445 * | −0.726 *** | −0.478 * | 0.033 | 0.622 ** | ||
CP * HD | −0.850 *** | 0.850 *** | 0.860 *** | 0.847 *** | 0.858 *** | 0.849 *** | 0.830 * | 0.780 *** | 0.363 | 0.818 *** | −0.587 ** | −0.869 | −0.488 * | 0.141 | 0.443 * | ||
Vegetation measurements | Tillage | ||||||||||||||||
CA | 0.383 ** | 0.390 ** | 0.395 ** | 0.396 ** | 0.29 | 0.456 ** | 0.13 | 0.344 * | 0.072 | −0.234 | −0.38 | −0.390 ** | 0.107 | ||||
CP | 0.767 *** | 0.664 *** | 0.731 *** | 0.673 *** | 0.507 *** | 0.729 *** | −0.323 * | 0.738 | −0.641 *** | −0.785 *** | −0.695 | −0.643 *** | 0.445 ** | ||||
Planting density | |||||||||||||||||
LD | 0.617 *** | 0.358 * | 0.489 *** | 0.384 ** | 0.333 * | 0.620 *** | −0.234 | 0.599 *** | −0.516 *** | −0.704 *** | −0.608 | −0.533 *** | 0.238 | ||||
HD | 0.791 *** | 0.717 *** | 0.768 *** | 0.723 *** | 0.640 *** | 0.801 *** | −0.062 | 0.803 *** | −0.562 *** | −0.752 *** | −0.74 | −0.740 *** | 0.503 *** | ||||
Combinations | |||||||||||||||||
CA * LD | 0.324 | 0.257 | 0.273 | 0.254 | 0.175 | 0.328 | −0.021 | 0.245 | −0.097 | −0.404 | −0.307 | −0.248 | 0.011 | ||||
CA * HD | 0.468 * | 0.579 ** | 0.543 * | 0.577 ** | 0.388 | 0.614 ** | 0.222 | 0.541 ** | 0.131 | −0.238 | −0.609 | −0.658 *** | 0.344 | ||||
CP * LD | 0.650 *** | 0.489 *** | 0.588 *** | 0.505 * | 0.245 | 0.613 ** | −0.402 | 0.596 ** | −0.610 ** | −0.732 *** | −0.614 | −0.517 ** | 0.444 * | ||||
CP * HD | 0.866 *** | 0.788 *** | 0.837 *** | 0.793 *** | 0.702 ** | 0.828 *** | −0.374 | 0.854 *** | −0.787 *** | −0.874 *** | −0.763 | −0.738 *** | 0.582 ** |
Equation | R2 | RSE | p-Value | ||
---|---|---|---|---|---|
Conservation | GY = −4.37 + 0.11·Lightness + 9.23·GA − 0.04·MCARI | 0.351 | 0.521 | 0.000 | |
Portion of variance | Lightness | 0.237 | |||
GA | 0.164 | ||||
MCARI | 0.159 | ||||
Conventional | GY = 16.56 −0.36·b* − 16.28·SAVI + 2.06·RDVI − 0.02·TCARI/OSAVI | 0.757 | 0.491 | 0.000 | |
Portion of variance | b* | 0.237 | |||
SAVI | 0.164 | ||||
RDVI | 0.159 | ||||
TCARI/OSAVI | 0.195 | ||||
Low density | GY = 5.36 − 0.26·b* + 10.21·OSAVI − 13.99·CCI | 0.516 | 0.609 | 0.000 | |
Portion of variance | b* | 0.203 | |||
OSAVI | 0.166 | ||||
CCI | 0.147 | ||||
High density | GY = 0.517 + 6.44·GGA + 3.14·OSAVI | 0.654 | 0.531 | 0.000 | |
Portion of variance | GGA | 0.353 | |||
OSAVI | 0.300 |
© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Share and Cite
Gracia-Romero, A.; Vergara-Díaz, O.; Thierfelder, C.; Cairns, J.E.; Kefauver, S.C.; Araus, J.L. Phenotyping Conservation Agriculture Management Effects on Ground and Aerial Remote Sensing Assessments of Maize Hybrids Performance in Zimbabwe. Remote Sens. 2018, 10, 349. https://doi.org/10.3390/rs10020349
Gracia-Romero A, Vergara-Díaz O, Thierfelder C, Cairns JE, Kefauver SC, Araus JL. Phenotyping Conservation Agriculture Management Effects on Ground and Aerial Remote Sensing Assessments of Maize Hybrids Performance in Zimbabwe. Remote Sensing. 2018; 10(2):349. https://doi.org/10.3390/rs10020349
Chicago/Turabian StyleGracia-Romero, Adrian, Omar Vergara-Díaz, Christian Thierfelder, Jill E. Cairns, Shawn C. Kefauver, and José L. Araus. 2018. "Phenotyping Conservation Agriculture Management Effects on Ground and Aerial Remote Sensing Assessments of Maize Hybrids Performance in Zimbabwe" Remote Sensing 10, no. 2: 349. https://doi.org/10.3390/rs10020349