Issue link: http://read.dmtmag.com/i/744696
www.goodfruit.com GOOD FRUIT GROWER NOVEMBER 2016 23 between X-rays and MRIs. "We're sort of at the X-ray stage today," he told the crowd. So far, the multispectral sensors used on drones can detect light reflection, but nothing that can be tied to a cer- tain problem or disease. A commonly used tool is the Normalized Difference Vegetation Index, which combines vis- ible and near-infrared light readings to detect relative amounts of healthy vege- tation. Shadows, reflective ground cover, sunburn protectants, cover crops and even moisture on the leaves can throw off those measurements. Kim envisions a possible switch from multispectral imaging to hyperspec- tral imaging, an ultra-high resolution technology that can identify unique electromagnetic "fingerprints" of dif- ferent diseases or pests. Oil companies use hyperspectral sensors to help spot underground reserves. However, hyper- spectral imaging requires an enormous amount of processing capacity, which in turn would require upgrades in band- width and connectivity for drones and operating computers to handle. For now, Kim and Digital Harvest have a partnership with Yamaha that allows them to operate in Washington and Oregon and eventually offer aerial monitoring and spraying services. The company is pursuing permits from the FAA and pesticide applicators licenses from both states to make that a reality. However, even if they had that paper - work in order today, "I wouldn't go to the tree fruit industry right now," he said in a follow-up interview with Good Fruit Grower. Instead, he said he would stick with potatoes or another crop that would benefit from spot spraying. "As much as people are anxious to want something now," the technology just isn't quite there yet, he said. "We got a lot of learn- ing to do." • TJ MULLINAX/GOOD FRUIT GROWER A Yamaha RMax UAV flies a prearranged flight path to spray from two tanks filled with water over a field. The capacity of each tank is about 2 gallons.