Melons, Pumpkins, Cantaloupes

Southern blight is a fungal disease that is most common in the tropics and subtropics, but also is found in the SE United States in the summer. In Maryland we usually find it in the southern part of the state in counties like St. Mary’s, Charles and Wicomico. It has been found this year in more northern counties such as Frederick, Montgomery and Baltimore.

One of the main things a grower can do to ensure a good quality pumpkin is to be sure they maintain their fungicide applications for as long as they continue to harvest fruit. Maintaining good foliage cover for your pumpkins results in pumpkin handles that are dark green stout and firm (fig. 1).

I have been seeing and receiving a few samples of yellowing (chlorosis) around the margins of cantaloupe leaves (Fig. 1). The marginal chlorosis observed in figure one would indicate salt burn, which is a noninfectious problem that mostly affects cantaloupes. This yellowing at the leaf margin is likely the result of guttation, which is how plants exude water at the margin of the leaf.

There have been several reports of odd looking damage to watermelon transplants being grown in greenhouses these past couple of weeks. The damage does not appear to be cold damage per se, but more of a strange environmental/weather one. Watermelon transplants, along with some other vegetables, began showing dark pitted lesions on their cotyledons (fig. 1).

Cantaloupe (Cucumis melo) is a warmseason crop that generated $319 million in sales in the U.S. in 2013 (1). Most commercial production occurs in California and Arizona, but historically production has centered in Maryland, Delaware and New Jersey (14). Cantaloupe grows best in well drained silty or sandy loam soils with a pH of 6.0-6.5. This vegetable is well-suited to growers with small-scale cultivation of 5 acres or less (14), as production doesn’t require a lot of specialized equipment, and fruit are highly marketable.