Predicting Harvest Date from Sorrel Bud and Calyx Measurements

Sorrel (Hibiscus sabdariffa) is an important Caribbean crop during the holiday season for the red calyx used to make a flavorful juice. Breeding work at UVI-AES has developed sorrel varieties to extend the season normally December through January to October through May. The objective was to measure sorrel bud and calyx development and use it to predict days to harvest the calyxes. Three inbred varieties and two hybrids were used. Seeds were planted in January and data collected twice a week on developing floral buds length and width. Upon flowering, data was collected on the expanding calyx and analysed with regression analysis. Harvest time was determined when the calyx expansion ceased as seeds in the capsule matured. January planting of sorrel resulted in floral induction within a month after germination due to the short-day photoperiod. Both developing floral bud length and width can be used to predict harvest date for sorrel varieties and hybrids.