Plant & Food Research's John Mitchell has led a programme trialling wireless sensors in kiwifruit as a way of detecting abnormal fruit.
Wireless sensor technology may one day be used in the horticulture industry to detect diseases or defects in stored fresh fruit.
A Plant & Food Research team developed a sensor at its Hamilton base at Ruakura, New Zealand and has been trialling it for green kiwifruit at a commercial cool store in the Bay of Plenty over the past two seasons.
Programme leader John Mitchell said the research unit wanted to find a scientifically sound way to detect any abnormal or undesirable fruit while in storage. At the peak of this season the team had 440 devices placed in 56 different pallets from 24 growers throughout the coolstore.
Mitchell said the sensors had functioned well over both seasons.
The bulk of New Zealand's kiwifruit is harvested from April-June when it is then graded, packed in pallets and stored in cool storage for up to six months.
Once stored, it was difficult to access individual packs of fruit to check its quality. If affected fruit was not identified and removed from packaging, it could spread throughout the stored crop and cause greater fruit loss, he said.
Mitchell developed a wireless system that can easily assess fruit quality.
The resulting sensor is about the size of a kiwifruit and can easily fit into a box without damaging fruit. It is battery-powered and costs about $15-$20 each.
Sensors measure volatile compounds emitted from the fruit as it is stored. The compounds indicate fruit quality or if there is an issue such as fungus or rot as well as monitoring temperature and humidity.
"The sensors are inserted in with the fruit and can get real time data collection on that condition non-invasively so it does no damage to the fruit," he said.
A signal is sent at hourly intervals to a network of receivers within the cool store before being fed to a computer, which sends it to a cloud network.
The data is turned into a colour-coded rating system which shows how much risk there is of the fruit being abnormal. Mitchell said the sensors had an 88 per cent overall accuracy and an 82 per cent success rate for rot detection.
Growers can then make decisions based on the data about whether the fruit can be stored, inspected or immediately shipped.
"The sensors also had a unique identification code that could be scanned and linked back to the code on the pallet, which helped trace defective fruit back to the grower." he said.
The devices are disposable because it is not practical to recover them as they go through the storage chain and transport chain, particularly if they are exported.
The technology is also transferable to other crops such as apples or gold kiwifruit. Feedback from cool store operators had indicated it could lead to major savings in labour. Initial projections put that cost saving at about $25-$30 million per year.
"The feedback that we have had from cool store operators is that they see it as a transformative technology for managing their inventory and reducing their waste and targeting their labour."
Source: stuff.co.nz