Weird Problem in Cantaloupe Fruit

Figure 1. Dark greasy or wet-looking areas of cantaloupe flesh. Image credit: D. Paulk

Updated: August 8, 2023

By Gerald (Jerry) Brust , and Karen Rane

Weird Problem in Cantaloupe Fruit

There have been some strange happenings in vegetable/fruit fields this season. The latest one is with cantaloup fruit. The fruit looks good when examining it from the outside, but cutting it open reveals an interior that has a dark, wet appearance in the fruit’s wall between the outer rind and the seed cavity (fig. 1). I first thought this was possibly a disease such as charcoal rot or black rot, but Karen Rane could find no disease-causing organisms in the damaged areas of the fruit or anywhere else in the fruit. She then came up with something called glaze or glassy fruit.

Glaze fruit is an abiotic problem that is characterized by the glassy appearance of part of the cantaloupe flesh. This spot then quickly takes on a wet appearance and over time begins to break down becoming soft and watery. This damaged area then gives off an alcoholic fermentation odor. Often times the outside of the fruit will remain clean, with no symptoms (fig. 2), but inside the fruit the watery rot is spreading. However sometimes a dark, greasy looking spot can become visible on the surface of the fruit at a very advanced stage of decline (fig. 3).

Would like to say that there is a good understanding as to what causes this decline in the fruit, but there is little definitive information out there about it. Among the factors likely to promote the appearance of this condition are: an excessive fruit load, cool weather that quickly turns hot, very dry soil conditions which promote poor root development, a deficiency in calcium and potassium and cultivar sensitivity. Bottom line, the causes are stressful weather conditions that affect some varieties more than others. Fortunately, this malady disappeared from this field after this harvest.

Cantaloupe with damaged flesh — Figure 2. Fruit with damaged flesh, but outside looks good. Image credit: D. Paulk

Cantaloupe with dark areas on outside surface — Figure 3. Fruit with outside surface with dark areas. Image credit: K. Rane, University of Maryland

This article appears in August 2023, Volume 14, Issue 6 of the Vegetable and Fruit News.

Vegetable Insect IPM

Vegetable & Fruit News, August 2023, Volume 14, Issue 6

Vegetable and Fruit News is a statewide publication for the commercial vegetable and fruit industries and is published monthly during the growing season (April through October). Subscribers will receive an email with the latest edition.

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