Effect of growth stage and variety on spectral radiance in winter wheat
| Autor: | H. Sembiring, William R. Raun, H. L. Lees, C. W. Woolfolk, Marvin L. Stone, D. A. Cossey, Wade Everett Thomason, John B. Solie, S. B. Phillips, M. J. DeLeon, J. M. LaRuffa, E. V. Lukina, Gordon V. Johnson |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Journal of Plant Nutrition. 23:141-149 |
| ISSN: | 1532-4087 0190-4167 |
| DOI: | 10.1080/01904160009382003 |
| Popis: | Before sensor‐based variable rate technology (VRT) can be used to reduce nitrogen (N) fertilizer rates in winter wheat (Triticum aestivum L.) spectral radiance readings must be understood. One prominent issue is the impact of crop growth stage on spectral radiance readings, and the ensuing problem of relating databases gathered at different locations and different stages of growth. In order to evaluate the impact of growth stage on spectral radiance, sensor readings were taken from a winter wheat variety trial and two long‐term N and phosphorus (P) fertility trials. The normalized difference vegetative index was computed using red and near infrared (NIR) spectral radiance measurements [NDVI=(NIR‐red)/(NIR+red)]. TotalNuptake in winter wheat at Feekes growth stages 4, 5, 7, and 8 was highly correlated with NDVI. In the variety trial, non‐significant differences in ND VI readings were noticed between the five common genotypes (by growth stage) grown in this region. However, slopes from linear regre... |
| Databáze: | OpenAIRE |
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