Comparison of aerial and ground remote sensing to quantify sudden death syndrome in soybeans

Abstract.

Discovered in 1971, Sudden Death Syndrome (SDS), caused by the fungus Fusarium virguliforme, has spread from the US to potentially infect plants worldwide. Yield loss of 10-15% and 70% in extreme cases are not uncommon for infected plants. Currently SDS impacts are scored by hand based on severity and percent of crop diseased. The quality of data collected over several hours is impacted due to changing diurnal environmental conditions. An alternative method for the rapid collection of high-quality data has been developed. A comparative evaluation of ground and aerial remote sensing methods for scoring of SDS is proposed to evaluate efficacy. The goal of this study is quantify and demonstrate that aerial remote sensing methods can be implemented to decease time commitment and improved scoring accuracy of SDS impacted soybeans. Plots were flown twice using several unmanned aerial systems (UASs) to capture a closed crop canopy and SDS emergence. Ground reflectance data and SDS scores were collected close to the time of flight. Flight plans were developed using mission planning software and UAS platforms were programmed to acquire images at an altitude of 60-120 m with 75-85% overlap. Image processing was conducted to produce orthomosaic and pigment index (PI) maps from the orthomosaics. PI values were compared to ground data. Preliminary results showed an inverse correlation of SDS scores and pigment index values. Results indicate aerial data proves more accurate for high instances of SDS. Accurate data can be collected over plot of 3-5 acres within 30-45 minutes.