Researchers develop a plant wearable patch that continuously monitors for plant diseases or other stresses, such as crop damage or extreme heat.
Identifying plant diseases is important to prevent the losses in the yield and quantity of the agricultural product. Continuous health monitoring of plants and disease detection is very critical for sustainable agriculture. Identification of diseases or other stress problems in plants helps to find the right solution for the particular disease. There are many methods currently for identifying plant diseases. One of the well known methods is image processing. Here, using image processing techniques, the system processes the visually observable patterns on the plant and identifies the disease accordingly. More reliable disease identification methods involve taking plant tissue samples and conducting an assay in a lab. The problem with this method is that it only gives growers one measurement, and there is a time lag between when growers take a sample and when they get the test results.
Researchers at North Carolina State University developed a wearable sensor or patch that plants can wear. The developed patch continuously monitors the plant health and identifies the plant diseases or other stresses, such as crop damage or extreme heat.
The wearable sensor created by the scientists monitors plant health by measuring the volatile organic compounds (VOCs) emitted by plants. Plants emit different VOCs under different circumstances. The sensor can detect these VOCs and by targeting VOCs that are relevant to specific diseases or plant stress, it can alert users about specific diseases or stress.
“Our technology monitors VOC emissions from the plant continuously, without harming the plant,” says Qingshan Wei, co-corresponding author of a paper on the work. “The prototype we’ve demonstrated stores this monitoring data, but future versions will transmit the data wirelessly. What we’ve developed allows growers to identify problems in the field – they wouldn’t have to wait to receive test results from a lab.”
The rectangular wearable patches developed are 30mm long and consist of a flexible material containing graphene-based sensors and flexible silver nanowires. The patches are coated with various chemical ligands that respond to the presence of specific VOCs. This allows sensors to detect and measure VOCs in gases released by the plant’s leaves.
The researcher tested the prototype of this wearable patch on tomato plants and monitored two types of stress: physical damage to the plant and infection by P. infestans, the pathogen that causes late blight disease in tomatoes. The patch identified VOCs associated with the physical damage within one to three hours. However, it was unable to detect the presence of P. infestans until three to four days after researchers inoculated the tomato plants.
“This is not markedly faster than the appearance of visual symptoms of late blight disease,” Wei says. “However, the monitoring system means growers don’t have to rely on detecting minute visual symptoms. Continuous monitoring would allow growers to identify plant diseases as quickly as possible, helping them limit the spread of the disease.”
The prototype currently detects over 13 different plant VOCs with high accuracy and the researchers are now working to develop a solar-powered patch that can monitor for temperature, humidity and other environmental variables as well as VOCs.
More information regarding the research can be found in the paper “Real-Time Monitoring of Plant Stresses via Chemiresistive Profiling of Leaf Volatiles by a Wearable Sensor” published in the Matter journal.