Skip to main content

Buckeye fruit rot on tomatoes

Symptoms of this fruit rot are similar to late blight and blossom end rot.  Distinguishing features include concentric rings in the dark brown lesions and white yeast-like sporulation of the pathogen, but these will not be present on all affected fruit in the field.  In contrast with fruit affected by late blight, affected tissue on fruit with buckeye rot are firm and smooth rather than rough.  And these symptoms can occur anywhere on fruit whereas blossom end rot symptoms typically are only at the blossom end of the fruit.

Buckeye fruit rot is caused by two pathogens that are closely related to the late blight pathogen: Phytophthora parasitica and P. capsici. The latter was found on the affected fruit shown here. These Phytophthora species do not move easily among plantings because their spores are moved by splashing water and in soil, rather than by air as occurs with Phytophthora infestans, the late blight pathogen.

Symptoms are most likely to occur on fruit touching or near soil where the pathogen was surviving between susceptible crops. The white growth on affected fruit in some images below is mostly spores of Phytophthora capsici.

buckeye fruit rot

buckeye fruit rot

buckeye fruit rot

buckeye fruit rot

Putting fruit with symptoms but no spores over night in a humid environment, such as on wet paper towel in a closed plastic bag, will induce the pathogen to produce spores confirming the fruit have buckeye fruit rot rather than late blight or blossom end rot.

buckeye blight on tomato

buckeye blight on tomato

buckeye blight on tomato

Skip to toolbar