A recent meeting of crop experts has revealed some new ideas for detecting the presence of crop pests before they strike. These ideas include sampling the air for pathogen traces, measuring volatile organic compounds and detecting decreases in leaf tissue content.
At the recent Association of Applied Biologists meeting in Lincolnshire several new crop pest detection technologies were unveiled. Scientists designing them had to be aware of the need to quickly identify the presence and abundance of the pests to allow farmers to react appropriately. If there is a large delay between detecting them and relaying the data to the farmer then the pests may be able to infect a large proportion of the crops before chemical controls have been applied.
Air sampling is one of the new technologies and aims to detect the presence and abundance of airborne pathogens. This information can help to inform farmers on where to apply chemical pesticides to their crops and can reduce unnecessary spraying of crops. In 2007 this method detected unexpectedly high levels of sclerotinia stem rot DNA in one test area. It was unusual as the disease is not normally found in the dry conditions experienced at the time. However it was proved correct as that year farmers recorded the highest peak in sclerotinia stem rot for more than a decade.
Electric Nose Technology detects airborne volatile organic compounds (VOCs) released by crop plants. VOCs are chemical signals released when the plant comes under attack from specific crop pests. These chemical signals then attract crop pest predators to the plant. The pest predators then act as “bodyguards” and attack crop pests which are present and force them from the plant.
NIR (Near-Infrared) reflectance methods are cost-effective and are able to analyse large areas of cropland. It measures the health of the crop canopy and detects areas with decreased leaf tissue. Leaf tissue damage through stress factors can be ruled out and the remaining results can be matched to specific plant pests and diseases.
More information on the recent meeting can be found here.