Chinese pear cultivars such as ‘Ya Li’, ‘Daisui Li’, ‘Seuri’, ‘Tse Li’, and ‘Shin Li’, and Korean pears such as ‘Shingo’, ‘Shinko’, ‘Okysankichi’, and ‘Dan be’ are susceptible to internal browning.
Internal browning on Asian pears is the main consumer complaint as it affects internal visual appearance, flavor, and texture (spongy), resulting in economic losses. This is a worldwide problem.
Development of brown to dark brown water-soaked areas in the core and/or flesh occur during storage of Chinese pears. A high incidence of internal browning symptoms have been reported after 2-3 months of cold storage of ‘Hosui’ and ‘Shinko’. Unfortunately, there is no visible external indication of internal browning.
To avoid internal breakdown development during cold storage and marketing, pick fruit grown under dry, hot, and long summer conditions of the San Joaquin Valley conditions before 180 days (3000 degree-days) after full bloom.
Pick fruit when most of the pears on the tree are still green, although a few at the top may begin to develop some light-yellow spots and smooth surface.
Fruit picked when the skin is completely yellow and smooth will develop internal breakdown after one or two months in cold storage.
We recommend cooling immediately at harvest, as cooling delays yellowing of the pears which results in increased incidence of internal browning in Chinese pears.
We suggest that growers who are having internal breakdown problems in Chinese pears keep records of the number of days after full bloom (degree-days) needed for their fruit to start turning light yellow to help them decide when to pick in subsequent years.
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