Postharvest heat treatment of apples to control San Jose scale (Quadraspidiotus perniciosus Comstock) and blue mold (Penicillium expansum Link) and maintain fruit firmness.

摘要

Postharvest heat treatments were applied to 3 apple cultivars (Anna, Golden Delicious and Jonathan). Treatment temperatures ranged from 38 to 50deg C and were applied from from 5 to 96 hours. The treatments 50degree C for 5 or 10 hours and 46degree C for 10 hours controlled all developmental stages of Q. perniciosus on Golden Delicious and Jonathan fruits. P. expansum germination was prevented by 46, 42 and 38degree C for 28, 34 and 42 hours, respectively. Control of P. expansum required longer treatments than those required to kill Q. perniciosus. Apples were damaged at 50degree C, although they could withstand at least 12 hours at 46degree C, and at least 24 hours at 42degree C. At 38degree C, no damage occurred on preclimacteric apples even after 96 hours, but when postclimacteric fruit were heated to 38degree C, heat damage occurred. The treatments which did not cause damage also maintained fruit firmness during post storage ripening. The results are discussed in the context of developing integrated postharvest heat treatments.