Drones carrying high-resolution multi-spectral, hyper-spectral and thermal cameras are being used to develop monitoring systems to help growers assess the health of their crops.
Dr Dongryeol Ryu is leading several related research projects, one of which targets water stress in fruit trees and grape vines. This has been funded and coordinated through Victoria’s Horticulture Centre of Excellence.
Dr Ryu says water stress causes trees and vines to shut down their transpiration systems, which normally help keep them cool, in order to conserve water. As a result, the temperature in the plant canopy rises, and this can be captured by the thermal cameras on drones flying overhead.
The thermal data is used to generate a water stress map of the crop, at a pixel resolution of 10 centimetres, within an hour. Water stress is otherwise measured tree-by-tree, with tests that take about 30 minutes each.
Dr Ryu says this system has the potential for widespread horticultural application as both drone and sensor technology becomes more affordable and software is developed to automate the collection and interpretation of thermal data. For orchardists and vineyards, maintaining a slight water stress helps to increase the sweetness—and the value—of their fruit.
Growers involved in the project include wine producers Wynns Coonawarra Estate and Curly Flat Winery. Funding was provided by the Victorian Department of Economic Development, Jobs, Transport and Resources.
In another project, Dr Ryu is using optical, multi-spectral and hyper-spectral imaging to identify signs of disease in tomato crops. The hyper-spectral images capture light across 240 bands in both visible and non-visible ranges and may allow growers to identify subtle signs of disease before they can be seen.
A foundational ‘library’ of crop images will provide a reference for ongoing crop health surveillance. This project has been funded by the Australian Processing Tomato Research Council Inc.
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