A Crop Health Sensor has been developed by a group of plant pathologists from Netherland-based Wageningen University. The sensor has been designed to detect diseases in leaves at early onset, which is achieved by using spectral reflectance analysis.
During the research, infection was induced in the apple leaves of various cultivars using apple scab (Venturia inequalis) and then evaluated. It was found that there was a distinction in the reflection between the infected leaves and the healthy leaves. The diseased leaves could also be distinguished after a few hours.
The lead scientist, Dr Jan van de Zande stated that following inoculation, the reflection of light was measured in intervals of 2, 4, 6 and 8 hours after the leaves were picked. It was determined that there were differences in the leaves, which had newly-opened at the top and the older leaves lower down the branch.
The sensor developed by the researchers helped ascertain the infection in a span of just four hours following the inoculation, which otherwise takes the human eye to detect the infection in 10 to 12 days.
Dr Zande also added that the timing and dose of chemicals could be determined by adapting the sensors and determining the crop health.
The plant pathologists also extended the trial into the orchards to determine if the wavelength could be assessed and disease symptom accurately identified. Another result of the five-year study was the development of sprayers that adapt to disease levels automatically, thus providing precise sustainable spraying when required.
Source: http://www.wur.nl/uk/