Developing Improved Wheat and Maize Varieties for Future Climates Using Remote Sensing at CIMMYT.

The effects of climate change will reduce wheat and maize yields in many regions of the world as the incident of abiotic and biotic stresses increase. Crop genetic improvement will play an essential role in increasing yield potential, and offsetting potential yield losses as a result of climate change, in many vulnerable regions. Advances in phenotyping are essential to capitalise on developments in conventional and molecular breeding and ensure crop genetic improvement for future food security. However the development of effective field-based high-throughput phenotyping platforms (HTPPs) remains a bottleneck for future breeding advances. Progress in sensors, aeronautics, and high-performance computing are paving the way for rapid phenotyping of large numbers of plots. Unmanned aerial vehicles (UAVs) are now being used in CIMMYT’s maize and wheat breeding programs to characterise traits associated with canopy temperature, plant water status, biomass production and senescence as well as investigating soil variance within trials. Thermal and multispectral aerial images are being used to derive indices relating to physiological and agronomic plant properties. Significant genetic correlations between airborne indices and yield/biomass, larger than the equivalent correlations between the ground-based measurements and yield/biomass, were identified. Recent analyses of managed drought trials highlighted the need to reduce the size of the residual variance relative to the genetic component of variance to increase genetic gains. Multispectral images are being successfully used to rapidly characterise experimental stations to develop experimental designs to reduce error variances, thereby increase the genetic signal to noise ratio to detect real differences between lines.