Unmanned aerial vehicle canopy reflectance data detects potassium deficiency and green peach aphid susceptibility in canola

Abstract

There is growing evidence that potassium deficiency in crop plants increases their susceptibility to herbivorous arthropods. The ability to remotely detect potassium deficiency in plants would be advantageous in targeting arthropod sampling and spatially optimizing potassium fertilizer to reduce yield loss due to the arthropod infestations. Four potassium fertilizer regimes were established in field plots of canola, with soil and plant nutrient concentrations tested on three occasions: 69 (seedling), 96 (stem elongation), and 113 (early flowering) days after sowing (DAS). On these dates, unmanned aerial vehicle (UAV) multi-spectral images of each plot were acquired at 15 and 120 m above ground achieving spatial (pixel) resolutions of 8.1 and 65 mm, respectively. At 69 and 96 DAS, field plants were transported to a laboratory with controlled lighting and imaged with a 240-band (390-890 nm) hyperspectral camera. At 113 DAS, all plots had become naturally infested with green peach aphids (Hemiptera: Aphididae), and intensive aphid counts were conducted. Potassium deficiency caused significant: (1) increase in concentrations of nitrogen in youngest mature leaves, (2) increase in green peach aphid density, (3) decrease in vegetation cover, (4) decrease in normalized difference vegetation indices (NDVI) and decrease in canola seed yield. UAV imagery with 65 mm spatial resolution showed higher & Dustin Severtson classification accuracy (72-100 %) than airborne imagery with 8 mm resolution (69-94 %), and bench top hyperspectral imagery acquired from field plants in laboratory conditions (78-88 %). When non-leaf pixels were removed from the UAV data, classification accuracies increased for 8 mm and 65 mm resolution images acquired 96 and 113 DAS. The study supports findings that UAV-acquired imagery has potential to identify regions containing nutrient deficiency and likely increased arthropod performance.

Evaluation of RGB, Color-Infrared and Multispectral Images Acquired from Unmanned Aerial Systems for the Estimation of Nitrogen Accumulation in Rice

“…Three cameras were mounted onboard the UAV separately for image collection and their technical specifications were listed in Table 2. The Tetracam mini-MCA6 (Tetracam Inc., Chatsworth, CA, USA) MS camera has six channels and was evaluated in the literature for other purposes [32,[38][39][40]. The camera has user configurable band pass filters (Andover Corporation, Salem, NH, USA) of 10-nm full-width at half-maximum and center wavelengths at blue (490 nm), green (550 nm), red (680 nm), red edge (720 nm), NIR1 (800 nm) and NIR2 (900 nm).…”

Robinia pseudoacacia L. Flower Analyzed by Using An Unmanned Aerial Vehicle (UAV)

“…The use of UAVs in agriculture [36][37][38]56,57,62], horticulture [51], plant ecology [66,68,89], and forestry [59,61,62,65] is increasing worldwide. However, UAVs were not heretofore used to quantify the flower production of black locust.…”

“…Near-infrared cameras were useful for collecting debilitation of plants caused by nutrient deficiency (potassium) or insect attacks (green peach aphid or bark beetle) and for calculating the normalized density vegetation index [37,59,61,92]. In the present study, the blue channel is used to analyze the flowers in the UAV pictures.…”

“…The Vertical Analyses are similar to that applied by Severtson et al [37] with the vertical FA ranging from 20 to 110 m above the starting point. The flower surface of the entire area (leaves, branches, stones, soil, etc.)…”

The potential of using Unmanned Aerial Vehicles (UAVs) for precision pest control of possums (Trichosurus vulpecula)

“…UAVs are routinely being used to: estimate tree crown diameters, tree fall and canopy openness (Inoue et al 2014;Panagiotidis et al 2017;Perroy et al 2017); detect and map invasive species (Gonzalez et al 2016;Müllerová et al 2017); detect nutrient and water deficiencies in agricultural crops (Gago et al 2014;Salamí et al 2014;Martínez et al 2017); and assist in the management of insect pests (Faiçal et al 2014;Näsi et al 2015;Severtson et al 2016). UAVs are also being trialled to deliver merchandise from retailers, such as Amazon's "Prime Air" service (Amazon 2017).…”