RELATIONSHIP BETWEEN GRAIN-YIELD AND REMOTELY-SENSED DATA IN WHEAT BREEDING EXPERIMENTS

Data from aerial infrared photographs have recently been proposed as a complementary analytical tool for evaluating genotype performance in breeders' trials. Our objective was to establish the relationships between spring wheat grain yield and remotely-sensed data in a variety experiment. Large genotype differences (P less-than-or-equal-to 0.05) in grain yield, red, and near infrared reflectance values occurred. Significant (P less-than-or-equal-to 0.05) regressions between grain yield and remoteley-sensed data were observed for two dates of flight, but these functions varied between dates of flight. A normalized difference vegetative index, as an estimate of crop productivity, indicated that spring wheats with the highest grain yields may show correspondingly high dry matter production. However, low r2 values for the remotely-sensed values suggest that much of the variability is not explained by these models. Future research must develop more accurate methods of remotely-sensed analysis, including standardizing the images, identifying the correct time with respect to stage of crop development for infrared photographs, incorporating crop harvest index data into the models, and adjusting for identified spatial variation.