Pest management is complex. Growers need to determine the type of pest they are dealing with, the extent of the infestation, other factors that may have contributed to the pest issue, what pesticides to use to fight the outbreak and how to apply them, etc. Before growers react to a pest situation in their fields, they first need to identify that they have a pest infestation. The timeliness of pest detections is crucial. If you catch the pest issue early, any treatment you make will have a better chance of success as the infestations haven't been given the time to develop and spread. If the issue goes undetected, an infestation can ruin an entire field's harvest. Crop monitoring and in-field scouting are critical steps for pest management that allows growers to identify and quantify pest pressure. Information gathered can be used to determine if pest control actions are warranted, and if they are, that information can help inform and guide a successful pest management plan. High-resolution aerial imagery offers a crop monitoring solution capable of detecting crop stress resulting from pest pressure.
Identifying pest issues
One of the most essential yet challenging aspects of pest management is identifying the problem. Growers have historically relied heavily on scouting and prior knowledge of field conditions and pest history to identify issues. However, unless you are scouting every foot of your field, it is easy for small, isolated pest issues to go undetected. These small pest issues can quickly become full-blown infestations if left undetected and unremedied. Local weather data can indicate conditions susceptible to pest pressure. Having a good understanding of the pest history in their fields can help growers focus in on areas vulnerable to pest pressure. However, relying on these methods alone to detect pest infestations relies on a certain amount of luck in turning up issues.
Aerial imagery for pest management
High-resolution aerial imagery can reveal subtle signs of crop stress that are caused by pest pressure. NDVI, CIR, and thermal imagery, in particular, can reveal crop stress that is not readily observed in color imagery or even on the field level.
NDVI imagery for pest management
NDVI imagery, a crop health index that measures plant biomass and chlorophyll levels, is engineered to detect crop stress. When crops are suffering from pest pressure, they show signs of stress, stress that NDVI imagery detects. While NDVI imagery is not a magic tool that will give you a pest-specific diagnosis, it is an excellent tool for identifying stressed areas that are potentially suffering from pest pressure and warrant an in-field inspection. If an in-field inspection does reveal a pest infestation, NDVI imagery can also be used to quantify the extent of the outbreak and highlight all plants that share the similar NDVI signatures as the plants suffering from pest pressure. The same imagery can then be used to guide variable rate pesticide treatments that target the most severely affected areas for higher rates while prescribing lower reates to areas with a more sparse pest presence. Services that offer the stress-detection capabilities of high-resolution NDVI imagery along with frequent and timely deliveries of an image subscription plan provide an unmatched solution for identifying and managing pest infestations.
The image to the right shows an alfalfa field that is suffering from a bad aphid infestation. The NDVI image of the field reflects the pest pressure as low vigor. According to this NDVI imagery, the aphid infestation seems to have originated and emanated from the northern part of the field.
Thermal imagery for pest management
Plants that are suffering from pest pressure react in the same way as humans do when we get sick; they develop a sort of fever. When plants are suffering from pest pressure, they become less efficient in their ability to transpire, causing the plant's temperature to rise. While thermal imagery is not a perfect pest detection solution, it has been proven very capable of exposing early signs of pest pressure.
In the image above, notice how the thermal image correlates to the NDVI image from the aphid infestation example discussed above. The area suffering from pest pressure exhibits hot thermal characteristics (orange/yellow color).
Infrared imagery for pest management
Infrared imagery correlates to plant biomass and has been used in the agriculture industry for decades to monitor crop health. While NDVI imagery provides information on plant biomass as well (in addition to chlorophyll levels), stand-alone infrared imagery can provide similar crop health insights from a slightly different perspective. Certain low vigor patterns will appear in earlier and greater detail in infrared imagery than it does in either thermal or NDVI imagery.
The image to the right shows a hops field that is suffering from an aphid infestation. Notice how the aphid infestation in the infrared image on the right (darker areas) is more evident than it is in the NDVI image on the right.
High-resolution imagery subscription services provide an unmatched affordable crop monitoring solution for pest management. Various image layers each provide different indicators that can help growers detect pest pressure in a timely manner, increasing their chances of success for any remedial action they decide to take. For more information on high-resolution aerial imagery as a pest management solution, please fill out the form below.