Characterization of Mature Paddles of Opuntia ficus-indica L. Using Morphological and Colorimetric Descriptors

Mexico is the world's leading producer of Opuntia ficus-indica. This kind of prickly pear is the most widespread and most commercially important cactus in Mexico. Morphological and colorimetric descriptors are among the most important agronomic traits because these parameters affect the yield, in such a way, the objective of the present research was to present a fast and reliable methodology to obtain the functional relationship in shape and color parameters of O. ficus indica cladodes, using a smartphone, a color meter, and open-access software. The acquisition and processing of images discovered interesting relationships between the Opuntia cladode's morphological characteristics, as well as colorimetric parameters of the cladodes. The non-linear data behaviors were fitted using deterministic models and CurveExpert software. Results of the study revealed that the best morphological descriptors were Circularity vs. Perimeter (r= 0.9815) and Aspect ratio vs. Roundness  (r= 0.9999).  In addition, mean values of the L*, C, and H color parameters were displayed in a window of a computer program online. It was found that the a-C relationship of the color parameters had the highest correlation coefficient (0.999). Therefore, it can be concluded that the morphological descriptors Circularity vs. Perimeter, Aspect Rate vs. Roundness, and a*-C color parameter can predict quickly and precisely the quality of O. ficus-indica.