1a.Objectives (from AD-416):
The proposed project is to implement portable LIDAR scanning technology on a tractor to collect cotton canopy geometrical characteristics, including leaf area profiles, leaf angle, branching, and canopy biomass. These characteristics will support other tractor-mounted proximal sensing devices to discriminate between stress tolerant and intolerant cotton cultivars.
1b.Approach (from AD-416):
The LIDAR system will be deployed in 2012 as part of the High-Throughput Phenotyping (HTP) project at ALARC. A genetic mapping population of 98 recombinant inbred lines (RILs), parents (NM24016 and TM-1), and differential checks will be grown at Maricopa for a third consecutive year. Field evaluations will include well-watered and water-limited treatments with two replicates each. The water-limited treatment will be initially applied at first flower. Point-cloud measurements of cotton canopy element locations will be collected weekly from tractor-based observations throughout July-August, which coincides with the critical stage of peak flowering and boll development as well as the hot, humid monsoon season in central and western Arizona. These data will be compared to random non-destructive estimates of canopy height, width, leaf area at four times. These observations will be in addition to other agronomic and physiological traits collected as part of the parent HTP experiment.
The project is directly related to Objective 2 of the parent project: “Develop and verify remote sensing methods, tools, and decision support systems”. Our joint project between USDA/ARS ALARC and University of Arizona scientists collected near-range LIDAR data over cotton plants grown for the 2012 High-Throughput Phenotyping (HTP) experiment. The project objective is to estimate cotton canopy characteristics, including height, width and leaf-angle distribution. These characteristics will help identify cotton varieties that are heat and drought stress tolerant. We have acquired, designed and deployed two LIDAR systems on a tractor-based platform. The system measures two rows of cotton plants simultaneously. The systems have been used to survey cotton plants in Maricopa field 119 as part of HTP. Results show that the system is performing as expected and returns plant height and width measurements accurate to 1-2 cm. Data acquisition volumes are large, exceeding 2GB of point cloud data on one survey. Multiple surveys per day are expected. Data processing protocols to filter and model plant canopy shapes are underway and will extend into FY 2013.