Impact of the maturity stage on harvest point of fruits and physiological quality of Physalis peruviana L. seeds

Abstract The objective of this work was to evaluate the physical-chemical and physiological changes during the maturation of fruits and seeds of P. peruviana and to determine the best stage for harvesting in the Brazillian semi-arid conditions. The fruits of P. peruviana were collected at five stages of maturation based on the color of the epicarp: stage 1: light green fruit; stage 2: yellowish-green; stage 3: light yellow with green color in the area that connects to the calyx; stage 4: yellow; stage 5: yellowish-orange. Physical and physico-chemical (length, diameter, fresh weight, fruit and calyx color, and total soluble solids) characteristics were evaluated. The physiological characteristics of the seeds were evaluated for water content and dry weight, germination percentage, germination speed index, emergence percentage, emergence speed index were also determined. The highest values of fruit weight, width, length and total soluble solids were recorded from stage S5, although it did not differ from stages S3 and S4. P. peruviana seeds reached their maximum physiological quality from S3 stage. On the other hand, the harvesting of fruits with characteristics meeting the minimum standards required for sale and consumption in natura should be carried out when the fruit and the calyx appear completely yellow, in the S4 stage. These findings point out which attributes may help improve current methods for monitoring ripening of physalis, in particular the commercially important specie P. peruviana.