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 bet ween spring wheat grain yield and remotely-sensed data in a variety ex periment. Large genotype differences (P less-than-or-equal-to 0.05) in grain yield, red, and near infrared reflectance values occurred. Sign ificant (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 differenc e vegetative index, as an estimate of crop productivity, indicated tha t spring wheats with the highest grain yields may show correspondingly high dry matter production. However, low r2 values for the remotely-s ensed values suggest that much of the variability is not explained by these models. Future research must develop more accurate methods of re motely-sensed analysis, including standardizing the images, identifyin g the correct time with respect to stage of crop development for infra red photographs, incorporating crop harvest index data into the models , and adjusting for identified spatial variation.