Melons, Pumpkins, Cantaloupes

Vegetable and Fruit News, Volume 14, Issue 6 (August 2023). Topics include:

A weird problem in cantaloupe fruit this season is that when examining it from the outside, the fruit looks good, but cutting it open reveals an interior with a dark, wet appearance in the fruit’s wall between the outer rind and the seed cavity (fig. 1).

The weather for the last week or so in our area has been ideal for air pollutants to cause injury to vegetable crops, especially cucurbits. One of these air pollutants is ozone, which is considered to be the most damaging phytotoxic air pollutant in North America. Injury is most likely during hot, humid weather with stagnant air masses.

Fruit and Vegetable News, Volume 12, Issue 4 (July 15, 2021)

I am seeing some plectosporium blight in a few pumpkin fields this year, not as bad as last year but still there. This disease will probably increase if we continue having frequent rains in some locations.

Commercially acceptable weed control is difficult to achieve in plasticulture vegetables even with pre- and post-emergent herbicide applications. These applications often do not provide season long weed control between rows. Moreover, several weed species have become resistant to commonly used postemergence herbicides, including common ragweed and pigweed species. Cover crops are an additional tool that could be successfully integrated into a weed management program.

Using Silicon, Stimplex and Plant Resistance in Pumpkin Production Systems to Reduce Plant Disease Loss

In the last few weeks several sweet corn fields as well as some watermelon and even a few tomato fields have been found with sulfur deficiencies (figs. 1 and 2). In sweet corn symptoms often appear as green leaves with light yellow or green striping on the newer leaves (fig. 1). In watermelon symptoms appear as a light green or light yellowing of the leaves of newer growth (fig. 2). In tomato unless severe you usually do not see any visible sulfur deficiency symptoms in the field, but fruit set and quality could be worse

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.

By this time of the season I usually see pumpkin fields infected with powdery mildew pretty commonly throughout the mid-Atlantic. And while powdery is present in many pumpkin fields it does not seem as bad as in previous years.