Plant Pathology

The biggest corn disease issue we will face this fall is stalk rot and stalk strength issues.

The Extension Cereal Crop Plant Pathology lab visited 110 corn fields in 20 counties during August 13 to August 23.

At the end of the cropping season, during harvest, there is a good opportunity to evaluate the crop stands across the field and observe if there is a way to improve the plant distribution in the future.

From now until freeze up is an ideal time to soil sample for SCN.

We recommend that dry edible bean growers soil sample their fields for soybean cyst nematode (SCN).

Question 1? What economically important diseases are emerging (and/or spreading) in North Dakota? Question 2?...

I recommend several resources that may help you identify your soybean diseases.

Sudden Death Syndrome (SDS) was first confirmed in the state in 2018 (Richland County), and in 2020 was confirmed hundreds of miles away in Cavalier County.

A few years ago, several fields experienced very severe charcoal rot in the Southeast and East central RRV.

Soybean Cyst Nematode (SCN) is the 2,000-pound gorilla in the room.

We encourage soybean growers to sample for soybean cyst nematode (SCN) this growing season, and NDSU Extension and the North Dakota Soybean Council are working together again to coordinate a soybean cyst nematode (SCN) soil testing program.

Questions about how to sample for SCN answered.

The trend of warm and dry conditions continue in the sugarbeet production areas of Minnesota and North Dakota.

We are seeing some limited Frogeye Leaf Spot in North Dakota. Given the low severity and advanced growth stages, yield loss is not a concern.

Cercospora leaf spot (CLS) (Figures 1 and 2) is the most damaging foliar disease of sugarbeet in North Dakota, Minnesota, Michigan and Montana.

Growers and agronomists have reported discolored awns and glumes of durum heads in several fields in western ND.

Currently, I am not getting calls about dry bean rust, but anticipate that it may appear soon. Scouting for dry bean rust is important even in a dry year.

We have been getting reports of sunflower rust, and suggest that growers scout for the disease.

We are starting to see the first stages of sunflower rust appear. IPM scout Tommy Crompton snapped a picture of the aecial stage of rust in a sunflower field last week (Figure 1).

I am following up last week’s soybean leaf disease article (bacterial blight, frogeye leaf spot and Septoria leaf spot) with another disease we are beginning to see, bacterial pustule.

In response to questions about leaf spots on soybeans, I am providing brief information and photos on three leaf diseases of soybeans; Bacterial blight, Septoria brown spot, and Frogeye leaf spot.

Prolonged dry and hot conditions reduce the likelihood of white mold occurring, yet alone causing significant yield loss.

Fusarium yellows have been identified in several fields in the Sidney factory district. The major Fusarium species found in sugarbeet are F. oxysporum and secorum.

The dry weather and low humidity have drastically lowered disease occurrence in wheat and barley.

The NDSU Plant Diagnostic Lab received its first Goss’s wilt sample last week, and one common question is how much yield loss can we expect from this disease?

The warm to hot temperatures, infrequent dews, and low humidity have contributed to the low scab risk in the state.

The extreme differences in temperature, low relative humidity, and water stress has led to unusual leaf spots on wheat.

At the end of the cropping season, during harvest, there is a good opportunity to evaluate the crop stands across the field and observe if there is a way to improve the plant distribution in the future.