A Low-Cost and High-Accuracy Non-Invasive System for the Monitoring of Fruit Growth

Measuring fruit growth can be useful not only to estimate its final weight but this information, in conjunction with environmental data and weather forecasts, can be used to estimate the water and nutrients requirement of an orchard. This paper describes the design of a very low cost system capable to measure sub-millimeter changes in the size of a fruit during its entire growth cycle. This solution overcomes any need of relocating the measuring unit, a severe limitation of other existing devices, without compromising the measurement resolution. The proposed solution uses low cost, easily available components, while maintaining the ability to measure changes in size higher than 30 μm and keeping a measuring range between 1.5 and 12 cm.