Content by Cody Molnar

Variety of pepper samples split open to reveal internal rot symptoms.

Pepper Internal Rot: Disease information and research updates

A new disease has been found in South Dakota pepper plants. While plants appear healthy and produce peppers that appear normal, many peppers will have a black mold growing inside. So, what’s going on with these plants?

Two broccoli plants exhibiting early black rot symptoms.

Black Rot of Brassica Crops

Black rot is an uncommon, but devastating bacterial disease in South Dakota that can develop during extended periods of hot and wet weather, leading to rapid and widespread crop loss.

Dark-green gelatinous masses on a patch of grass.

Nostoc in Lawns

Nostoc is a genus of cyanobacteria that form colonies in gelatinous masses. In South Dakota, it commonly appears in home lawns, notably in patches where grass is not growing, especially after periods of rain.

Person carving a pumpkin on an outdoor picnic bench.

Pumpkin Carving Preservation

Pumpkin carvers can use several techniques to slow or prevent the spread of pathogens and help their jack-o’-lanterns last longer. Learn some expert tips for getting the most out of your pumpkin carvings this fall.

Two white flowers with green leaves. The first flower has an abnormal fused bloom.

Fasciation: What’s going on with my plant?

Fasciation is a malformation of plant parts commonly manifested as enlargement, flattening or cojoining. The abnormal growth of plants can be uniquely puzzling and beautiful at the same time.

A green corn leaf with yellow to brown spots throughout.

Corn Disease Update: September 2, 2025

As of September 2, 2025, a number of corn diseases have been reported and confirmed throughout South Dakota. View our latest findings as we approach the fall harvest season.

Coneflower with Aster yellows disease.

Aster Yellows Phytoplasma

Aster yellows is a phytoplasmal disease carried and introduced by aster leafhopper. It is known to infect over 80 different plant families, as the aster leafhopper has extremely broad feeding habits.

Corn leaf samples with Southern Rust and Tar Spot.

Corn Diseases in South Dakota Update

Several South Dakota counties have confirmed positive cases of Southern Rust and Tar Spot this growing season. See our latest recommendations for dealing with these diseases before they become a problem.

Green plant leaf with several small, black beetles on it.

SDSU Extension welcomes new plant pathologist

August 12, 2025

South Dakota State University Extension is pleased to welcome Cody Molnar as a new Horticulture Plant Pathology Field Specialist.

Three chokecherry trees exhibiting various x-disease symptoms on their foliage.

X-Disease in Chokecherries

X-disease is the name given to a set of diseases caused by a strain of the bacteria “Candidatus Phytoplasma pruni” that primarily affects stone fruits. Infected plants will typically display yellowing or reddening of their leaves by mid summer.