Scientists at the National Physical Laboratory (NPL), the UK’s Measurement Institute have developed an imaging technology which can identify the ripeness of strawberries before they are picked. The developers now hope to work with the agricultural industry to turn it into fruit picking robots that will reduce food waste and improve productivity.
Successful trials have been completed on strawberries as well as a number of other crops. The software has also been designed to “learn” based on past experience, so tests for new crops can be quickly developed.
The work began in 2009, as a project to identify the ripeness of cauliflower, which was a problem for pickers due to its leafy exterior. The technology was completed and successfully demonstrated, but a drop off in demand for cauliflower stalled the project. Having proved the concept, lead scientist Richard Dudley began developing the technology for a wider range of fruit and vegetables and is taking it to market.
“The focus now is strawberries. This is a fairly easy fruit to measure as it has high water content and dry leaves, and microwave imaging is particularly useful for identifying water levels. Strawberries are also a high value fruit which are very time-consuming to pick so there is a stronger business case to implement automated picking technology for strawberries than with some other crops,” said Dudley.
Annual waste from picking unripe crops can be high and can mean many thousands of pounds of lost revenue for farms every year. As a result, the agriculture industry is constantly on the lookout for more efficient ways of harvesting crops.
NPL’s new technology uses radio frequencies, microwaves, terahertz, and the far-infra red. These four parts of the electromagnetic spectrum all have potential to safely penetrate the crop layers and identify whether the crop meets the pre-designed criteria for ripeness, for a relatively low cost. NPL has developed this technology and the requisite software for crop identification and selection.