AgVue worked with a Pennsylvania research company to image cucumber plots treated with various fungicides to test the efficacy of the mildew preventing agents. Three fungicides were compared with an untreated control plot.
Early detection was crucial in this study to determine how early in plant growth cycle the disease could be detected. Secondarily was the ability to show which treatment was the most effective. The results are shown below in the visible (RGB) spectrum and modified NDVI images. The RGB images show signs of the disease affecting plant health in each test row, but the extent of the plant damage isn’t obvious. A canopy separation tool was used to isolate the plant canopies from the soil and then an NDVI calculation was performed. When comparing the visual RGB to NDVI imaging, the efficacy of each treatment becomes much more apparent.
The multispectral/NDVI image clearly shows the middle-right row of cucumbers is the untreated row. The treatment on the far right row has slowed the mildew growth, but not entirely. The far left row looks healthier, showing the treatment in that row is doing well, and the middle left row is clearly the most effective treatment and shows almost no loss of vigor due to Downey mildew.
This example illustrates the value of using drones for imaging plants for research of chemical test trials and determining the most effective treatments for very specific pathogens.