Jerry Brust, IPM Vegetable Specialist, University of Maryland; jbrust@umd.edu
One of the main things a grower can do to ensure a good quality pumpkin is to be sure they maintain their fungicide applications until they harvest fruit. However, if it remains as dry as it has been you can increase the time between applications to 10 or 14 days rather than weekly when we have rain. Maintaining good foliage cover for your pumpkins results in pumpkin handles that are dark green stout and firm (Figure 1). If fungicides are cut too soon foliage can be lost to powdery or downy mildews or other foliar diseases and this defoliation can result in handles that are brown, withered and decayed (Figure 2).
Another reason to keep your foliage in good shape is that pumpkins that are maturing and turning color need to be protected from the sun. With our hotter and usually sunnier Septembers, pumpkin fruit can easily become sunburned, or sun scalded. A spot on orange (or at times green) pumpkins that is facing the sun can result in reddish or white-bleached areas (Figure 3). These sunburn/sunscald areas on the fruit often become soft with rot setting in a few weeks later. Clear sunny days with highs in the mid-80s are perfect settings for sunburn/sunscald fruit especially if the fruit has been clipped and left in the field. I have seen several pumpkin fields (especially U-Pick ones) over the last 5-6 years that suffered significant losses to sunburn because of reduced leaf cover due to unchecked foliage diseases.
Figure 1. Harvested pumpkins with good handles.
Figure 2. Harvested pumpkins with poor handles.
Figure 3. Sunburn (red spot) and sun scald (white spot) on harvested pumpkins.
