Szacowanie plonów roślin uprawnych na podstawie naziemnych pomiarów spektralnych

The objective of the study was to compare the variability of hyperspectral characteristics of winter oilseed rape and winter spelt in the early growing season and to determine the usefulness of vegetation indices obtained during the ground-based hyperspectral measurements to predict the yield of these crops. Field hyperspectral measurements were taken from the experimental plots of three varieties of winter oilseed rape and four winter spelt varieties during the fi rst part of the growing season. The oilseed rape plots were sown at four dates in the autumn and the spelt plots were fertilized in six schemes. Vegetation indices were calculated on the basis of the reflectance factors of the visible and near-infrared bands and their logarithmic and first derivative transformations. Then, relationships between the vegetation indices and oilseed rape and spelt yields were analyzed. Among the unprocessed indices the highest R2 values (0.86) were obtained for the relationship between the winter rape yield and NDVI550-775 recorded at the beginning of the fl owering stage. The transformation of the spectral data improved the relationship between the NDVI675-775, NDVI820-980, SRWI870-1260 and yield up to 0.86. The winter spelt yield was most strongly correlated with NDVI550-775 (R2=0.80) at the stem elongation stage and the transformation of the spectral data did not improve the relationship.