Shortages seem to be the theme of 2020 and 2021. Everything from meat to commodities and even semi-conductors made the list of possible or definite shortages. Now, the early onset of a fungus that attacks vegetables could leave us with no pumpkin pie at Thanksgiving and no Jack-o-Lantern's at Halloween!

What is Phytophthora?

P. capsici blight, unfortunately, has hit pumpkins early and hard this year, endangering the supply of commercially canned purée as well as jack 'o lanterns. "Home gardeners may also see it affect their ability to grow tomatoes, peppers, cucumbers, and squash." [source] P. capsici: infects pumpkins and other cucurbits, bell peppers, and eggplant.

Phytophthora, classified as oomycetes, is a fungal genus with 170 described species and another 100-500 estimated waiting for discovery. Phytophthora is one of the water molds, and not one species is up to any good in garden or field.

P. infestans is the bug responsible for the Irish potato famine of the 19th century and is a severe problem in potatoes today. Members of this troublesome genus (listed below) infect the Solanaceae family, including potatoes and eggplant, cucurbits including squash and pumpkin, strawberries, and many economically significant trees, flowers, and shrubs.  P. parasitica attacks bell peppers, tomatoes, and eggplant. This infection is commonly called buckeye rot.

This article includes general information applicable to pumpkins, potatoes, tomatoes, strawberries, and peppers, common vegetables grown in home gardens. The source links throughout this article have pictures, which are, of course, handy to diagnose. 

General signs and symptoms of infection for pumpkins and potatoes

Here is a condensed list of general symptoms of infection to help with spotting and diagnosing.  

General First Signs: Water-soaked spots are small, pale to dark olive green, angular to irregular, and present on the lower leaves at the leaf tips or edges. Lesions rapidly expand into large, dark brown to purplish-black dead areas during cool, moist weather.