The tamarillo: Fruit growth and maturation, ripening, respiration, and the role of ethylene

The tamarillo (tree tomato, Cyphomandra betacea Sendt.) flowers and sets fruit over an extended period. Many blossoms and young fruits abscise; survival of tagged fruitlets ranged from 0 to 32%. Tagged fruits were harvested at known ages for measurement of size and shape, respiration rate, ethylene production, and response to ethylene treatment. Fruit growth followed a single sigmoid pattern, and fruits were commercially mature at 21–24 weeks after anthesis. The amount of red skin pigment increased with age from 15 weeks, but harvesting of immature fruits appeared to stop red pigment development. Fruits harvested at 12–19 weeks or younger shrivelled in storage. Respiration studies showed tamarillo fruits to be non‐climacteric, and only traces of ethylene were produced until final senescence. Ethylene treatment increased the respiration rate and hastened senescence of harvested fruits of all ages. The yellow strain behaved similarly to the red and had a somewhat longer storage life.