Can You Eat Apples with Moldy Core? Identifying and Controlling It in One Article

Apple moldy core mainly damages the fruit, causing heart rot and early drop. The core of the diseased fruit turns brown and is filled with grayish-green or pink mold, rotting gradually outward from the locules, and the flesh tastes extremely bitter.So can you eat apples with moldy core? How do you identify it? What control measures are there?

Can you eat apples with moldy core?

Apples with moldy core must not be eaten.

How do you identify apple moldy core?

1. Apple moldy core mainly damages the fruit, and is an important fruit disease especially of Delicious (Red Delicious) strain cultivars and of Fujin, Luxiang and others bred using Delicious strain cultivars as parents. Its symptoms appear in 2 forms.

(1) Moldy core type: mold of grayish-green, grayish-white, grayish-black and other colors is produced in the locules, and this mold is confined to the locules.

(2) Heart rot type: the flesh in the core area rots from the locules outward, and in severe cases the flesh can rot all the way through to the fruit surface. The rotten flesh tastes bitter; severely affected young fruit drops early, while lightly affected fruit can ripen normally, but the locules can still develop the disease from the ripening stage to after harvest.

2. Pathogens: caused by mixed infection by various fungi, mainly Alternaria alternata (Fr.) Keissl, which produces black mold layers; Trichothecium roseum (Bull.) Link, which produces pink or pinkish mold layers; Cephalosporium sp., which produces gray mold layers; Fusarium moniliforme Sheld; Penicillium sp.; and Phomopsis sp. (listed in the source as Penicillium sp.), all belonging to the Deuteromycotina fungi. The dominant species differ slightly from place to place; in some areas Alternaria fungi dominate, while Fusarium is rare. In the later storage period, Trichothecium roseum is often predominant in Golden Delicious fruit.

3. Transmission route: the pathogen overwinters as mycelium in diseased mummified fruit or necrotic tissue, and as spores hidden among the bud scales. The following year it produces various types of spores, which spread by wind and rain; the spores enter the locules through the calyx tube. The pathogen mainly invades during the flowering period, after which the spores lie dormant inside the fruit core; as the fruit develops, the mold begins to multiply. Diseased fruit can be seen dropping in June, but mostly in the later stages of fruit growth. Some diseased fruit shows symptoms only during storage, causing moldy rot.

4. Conditions for occurrence: the occurrence of this disease is closely related to climate and cultivar. Early rain, abundant rain, humid climate, low-lying orchards, dense canopy and poor ventilation favor the disease. Among apple cultivars, those with a large calyx opening and a long calyx tube connected to the core are susceptible; those with a small calyx opening and a short calyx tube are more resistant. Delicious strain cultivars such as Starking, Huanong No. 1, Delicious, Fujin, Luxiang and Red Crown have long, wide calyx tubes and suffer severe disease; Golden Delicious and others with a half-open calyx are less affected; Zhuguang, with a closed calyx and short calyx tube, shows resistance.

What control measures are there for apple moldy core?

Control methods:

1. In severely affected orchards, choose and plant resistant cultivars. Such as the Fengxian Red Fuji apple from China.

2. Strengthen cultivation management, prune rationally, keep the canopy well ventilated and exposed to light, pay attention to drainage, and rationally increase the application of organic fertilizer.

3. Remove the source of primary infection. In late autumn and early winter, remove diseased fruit, mummified fruit and diseased branches, and burn them in a centralized manner.

4. Strengthen storage-period management. Develop simple controlled-atmosphere storage or cold storage; during storage the fruit store temperature should be kept at 0.5-1°C and the relative humidity at about 90%.

5. Chemical control. Spray once before flowering, after flowering and during the young fruit stage at half-month intervals. Spray with 1:2:200 Bordeaux mixture, or 10% polyoxin wettable powder at 1200-1500 times dilution, or 50% iprodione wettable powder at 1500 times dilution.