Limitations to High Throughput Phenotyping

While HTP offers many advantages to the plant breeding industry, it is important to discuss some limitations of the technology. A few considerations are:

• Amount of data – This technology increases the VOLUME of data we can collect but does not cut down the amount of time spent collecting data. It allows breeders to have access to more data to support and make decisions more soundly.
• Price – Depending on the drone and sensors used, these UAVs can come with a big price tag. The DJI Phantom 4 (figure 10, right) is purchased with the sensor included and is on the cheaper end when it comes to UAVs. In comparison, the DJI Matrice 300 (figure 10, left) without the sensors included costs approximately six times as much as the DJI Phantom 4. In addition, purchasing the most commonly used RGB and multispectral sensors to attach to the DJI Matrice 300 UAV will double the price. There are also other costs associated with accessories like batteries and purchasing software to process the data.
• Software – This technology is still being developed, which presents a few issues. During drone setup the software can glitch causing startup to take longer than just ‘pushing a button and turning it on’. This can be frustrating for researchers who have a limited window to collect data due to the weather and plant growth stages.
• Data storage – HTP can collect immense amounts of data, so you need the capacity to store all that data. To give you an idea, saving RGB and Multispectral images from a field that is roughly 2800 feet (or 1/20 of an acre) will require about 60 gigabytes of storage.
• Indirect measurements – We cannot directly measure every trait of interest, so we must use indirect measurements of traits that correlate with those we are interested in. For example, we cannot distinguish diseases in crops using a UAV. Instead, we can use sensors to determine plant health based on the calculated NDVI. Plant health can be correlated with the amount of disease present in a crop. However, plant health can be affected by many factors like drought conditions and nutrient deficiencies, so it is important to still be present in the field to make visual observations.

Despite these concerns, researchers believe UAVs will have a beneficial impact in the agriculture community. Scientists are continuing to conduct research to minimize these issues and improve the technologies.