The effects of fruit maturation, delayed storage and ethylene treatment on the incidence of low-temperature breakdown of 'Hayward' kiwifruit.

BACKGROUND

Low-temperature breakdown (LTB), a disorder inducing quality loss, during and after cold storage of 'Hayward' kiwifruit was investigated. Harvested kiwifruits during fruit maturation or after delayed storage (DS) at 20 °C for 0, 1, 2, 3 and 4 weeks and 1 µL L⁻¹ ethylene treatment for 24 h were stored at -0.5 °C for 24 weeks and additional ripening at 20 °C for 5 days. Fruit quality indices and LTB incidence and severity were determined before and after treatments.

RESULTS

Harvested fruits ripened during maturation, DS and after ethylene treatment. After storage and shelf life, fruits of all treatments were at complete ripening stage. LTB incidence of early harvested fruits was high, while that of fruits of the mid (third) and late harvests was low. Fruits of the third harvest date showed progressively increased LTB incidence with increasing duration of DS to as high as 95-100% after 4 weeks. Ethylene-treated fruits showed a comparable increase in LTB to that corresponding to 2-3 weeks of DS.

CONCLUSION

In contrast to fruit maturation, postharvest (after harvest and before storage) DS at non-chilling temperature and ethylene treatment advanced the ripening of 'Hayward' kiwifruit and resulted in increased LTB incidence.