Growth Stage, Development, and Spatial Variability in Corn Evaluated Using Optical Sensor Readings**Contribution from the Oklahoma Agricultural Experiment Station and the International Maize and Wheat Improvement Center (CIMMYT)
| Autor: | John B. Solie, William R. Raun, Gordon V. Johnson, K. L. Martin, Marvin L. Stone, K. W. Freeman, R. W. Mullen |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Journal of Plant Nutrition. 28:173-182 |
| ISSN: | 1532-4087 0190-4167 |
| DOI: | 10.1081/pln-200042277 |
| Popis: | Knowing the exact stage of growth where expressed plant variability is at a maximum might lead to the identification of times when in-season fertilization could have the greatest impact. One field experiment was initiated to measure daily plant growth and spatial variability in corn (Zea mays L.) over the entire growth cycle using optical sensor readings (normalized difference vegetative index, or NDVI) collected every 0.05 m in length, 0.6 m wide from 4 corn rows, 27 m in length. Averaged over all 4 rows, plants were spaced 21 ± 7 cm apart. For each row and sensing date, the mean, standard deviation, and coefficient of variation (CV) were computed from the NDVI readings. Eighteen days after planting, NDVI values were near 0.20, and later peaked near 0.81, 54 days after planting at the 10-leaf growth stage (V10). Coefficients of variation were found to peak much earlier, 33 to 35 days after planting at the 6-leaf growth stage (V6), (31% to 34% during this period). Expressed spatial variability de... |
| Databáze: | OpenAIRE |
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