The value of infrared photography has been appreciated since the late ‘30’s. Its use in farming is being recognized as we move toward site specific precision in agriculture. The ability to make use of digital technology, and color enhancement of those images, allows for quick/easy interpretation of the information. The primary function of this equipment is to acquire images of vegetation in the red, NIR, blue and green bands of the spectrum, and link that to the spatial/temporal aspects of the crop.
This season we will be using both the 3 sensor ADC (Tetracam) and Tetracam’s new 12 sensor MCA system. From this the level of vigor/stress can be calculated using one of the standard vegetation indices, such as an NDVI or GNDVI. The primary use of infrared photography is in vegetation studies, because healthy green vegetation is a very strong reflector of near infrared radiation (NIR). This data can then be classed, and color ramped, and used in the creation of prescription maps. These maps are the basis of our management zones - zones that can be used for VRA/VRI/VRP, etc.
The image below was taken in August, 2010, Hartley, TX. Image depicts early potato psyllid activity. Image processing by Dr. Jeff Willers, USDA/ARS, Mississippi State Univ.
Dr. Willers has spent the last several years developing and perfecting the process of creating scout maps for consultants in Mississippi and Georgia. He uses both aerial IR images and digital elevation maps (DEM), to emphasize areas of high likelihood of insect infestation. Jeff's pioneering efforts have led to significant advancements in the art of field scouting. Primarily, this work has focused on tarnished plant bug infestations in cotton. By combining areas of plant vigor/stress with elevation (spectral/spatial aspects), he is able to define areas of high probability for infestations, and areas of little, to no, tarnished plant bug.
Below is an example of such a ‘scout map’ - image of a cotton field that Jeff that has put through the process of 'ground truthing', and insect numbers correlated to plant vigor.
Dr. Willers is now beginning to work with imagery from the High Plains of Texas in an attempt to detect early infestations of banks grass mites and two spotted mites in corn. The software detects change, when a timely series of images of a field are processed. Once he has established a spectral signature for mites in corn, the software isolates areas with the particular signature. We are excited about the possibility of being able to locate early mite infestations – those populations that normally escape detection by regular field inspections.
Potatoe field - Hartley, TX - 2010. Unsupervised Classification - 25 Classes. Courtesy of Dr. Jeff Willers, USDA/ARS, Miss State Univ..
Scout Map - Cotton, Boliva, Miss. Pseudo-liklihood Classification map. 2M resolution. Graduated symbols show pre- adn post-insecticide applicaiton counts for Tarnish Plant Bugs at various sample sites during June 2008. Courtesy of Dr. Jeff Willers, USDA/ARS, Miss State Univ..