Causes and Control Methods of Pear Black Heart Disease

In the early stage of the disease, brown patches appear on the outer skin of the fruit core. When the browning gradually expands to the entire core, the flesh shows browning with indistinct boundaries. Affected fruit deteriorates in flavor, seriously affecting the fresh-keeping storage life of Ya pears.

Depending on the storage period and conditions, this disease can be divided into two types: early-stage black heart disease and late-stage black heart disease. The former occurs 30-50 d after being placed in cold storage and is considered to be caused by low-temperature injury during storage. The latter usually occurs under earthen cellar storage conditions, mostly around the Spring Festival of the following year, and is preliminarily considered possibly related to the natural senescence of the fruit. In addition, a relatively high CO2 concentration in the storage environment can also lead to the occurrence of black heart disease in Ya pears. The browning of the pear core is mainly caused by increased polyphenol oxidase activity, which promotes oxidative browning reactions in the core and flesh tissues. Calcium is also a major mineral nutrient element affecting black heart in Ya pears.

For control, when cold storage is used, the temperature should be gradually lowered to 0°C, which can reduce early-stage black heart disease caused by low-temperature injury.