US: Using remote sensing technology, researchers at University of Minnesota in the US, are developing an innovative tool to help soybean farmers. The tool will alert farmer about stress factor in soybean fields, such as an infestation of soybean aphids. The new tool, according to Ian MacRae, an entomologist, will increase farmers’ scouting efficiency.
The science behind this concept is based on the infrared and near-infrared light reflected from the plants, MacRae explained. “Plants have evolved so they will reflect infrared, near-infrared and green, since that is the pigment in the plant,” he said. “However, when a plant gets stressed the chlorophyll pigment is decreased, and when that happens less of the near-infrared light is reflected as well. So if you had something that could ‘see’ infrared and near-infrared, it could give an indication if a plant is healthy or under stress.”
This stress, he noted, wouldn’t be limited to insect infestations, but rather such things as drought and disease problems as well.
MacRae introduced those attending the recent Crops and Soils Day at the Northwest Research and Outreach Center to radiometers that detect infrared and near-infrared radiation. These devices were mounted on poles in the field and pointed down on the soybean crop.
They were situated in such a way that they could scan both the soybeans that were aphid-free due to cages being placed over small areas of the crop before the aphids arrived, and an area that had a high population of soybean aphids that was held in place by a net cage over that certain area.
The difference in infrared and near-infrared radiation was then compared in an effort to develop a baseline for those plants under stress and those not experiencing stress.