Effect of Forced, Hot-Air Treatment of Papaya Fruit on Fruit Quality and Incidence of Postharvest Diseases. Kate A. Nishijima, USDA-ARS, Tropical Fruit and Vegetable Research Laboratory, Hilo, HI 96720. Carole K. Miura, John W. Armstrong, Steven A. Brown, and Benjamin K. S. Hu. Dept. of Mathematics, College of Arts and Sciences, University of Hawaii at Hilo, Hilo 96720-4091; USDA-ARS, Tropical Fruit and Vegetable Research Lab, Hilo, HI 96720; and Retired, USDA-APHIS, Hilo, HI 96720. Plant Dis. 76:723-727. Accepted for publication 10 December 1991. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1992. DOI: 10.1094/PD-76-0723.

Forced, hot-air (48.5 C for 3–4 hr) treatment of papaya fruit (Carica papaya), a recently developed quarantine treatment for fruit flies, did not significantly reduce incidences of postharvest diseases when compared with fungicide or hot-water treatments. However, when hot-air treatment was combined with thiabendazole (TBZ) (4 g a.i./L) application or hot-water immersion (49 C for 20 min), the incidence of most postharvest diseases was reduced. Although disease incidences were not significantly affected by the sequence of hot-air or hot-water application, degreening (lack of surface ripening), along with pitting and scalding symptoms significantly (P < 0.01) increased when hot-water preceded hot-air treatment, but these symptoms did not occur when hot-air preceded hot-water treatment. The hot-air treatment was associated with an increase in the incidence of internal lumpiness (hardened lumps of flesh in ripe fruit) when compared with untreated fruit.

Keyword(s): Botryodiplodia theobromae, Colletotrichum gloeosporioides, Mycosphaerella sp., Phomopsis sp.