SUNIndx: Visual identification of sun stressed-areas of the fruit using a reflectance index (Sun Index) from hyperspectral images to predict sunscald-risk postharvest on ‘Granny Smith’ apples

Abstract

Sunscald is a postharvest peel disorder on apples and pears caused by sun stress during fruit growth. It has been shown that a newly developed sun index using wavelength associated with chlorophylls and carotenoids can be used to detect sun-stressed areas on the fruit and use it as a sun-risk predictor at harvest for sunscald development in postharvest. SUNIndx is a group of functions coded in Python to process spectral data, calculate the index, visualize it in the hyperspectral image, and generate a sunscald-risk category of ‘Granny Smith’ apples at harvest. This software can be manipulated and tailored to detect sun stress in different fresh produce crops based on hyperspectral images.

Keywords

• Chlorophyll wavelengths
• Carotenoids
• Reflectance indexes
• Sunburn