Wet conditions have stalled corn and soybean planting but may be ramping up the risk of foliar disease in wheat.
Ohio’s wheat crop is either at or past Feeke’s Growth Stage 10 (boot) and now is the time to scout fields if you have not already. Foliar diseases like Septoria leaf spot and powdery mildew thrive in cool, wet conditions and can potentially reduce grain yield and quality by damaging the flag leaf. When scouting for Septoria leaf spot, look for irregular brown blotches that may become bleached in appearance and contain small, blackish dots (fungal fruiting bodies). The main sign of powdery mildew is fluffy, whiteish-gray powdery growth (called pustules) on the leaf surface and lower stem. As the pustules age they will become covered with black dots on the surface.
As temperatures increase this week, keep an eye out for other potential foliar diseases such as Stagonospora leaf blotch and leaf rust. Stagonospora leaf blotch symptoms develop when temperatures are between 68- and 81-degrees Fahrenheit and typically appear as brown, lens-shaped lesions surrounded by yellow halos. Leaf rust also prefers warmer temperatures coupled with rainy, humid conditions and can be diagnosed by its round, orangish-red pustules scattered across the leaf surface.
If disease is present and conditions remain favorable for further disease development, consider a fungicide application between Feekes Stages 8 through 10 to prevent disease from reaching the flag leaf. Fungicide options can be found at https://cropprotectionnetwork.org/publications/fungicide-efficacy-for-control-of-wheat-diseases.
Once wheat reaches flowering, Fusarium head blight or head scab becomes the main concern. Risk for head scab infection and deoxynivalenol (DON) contamination is greatest when wet, humid conditions coincide with flowering. To estimate the risk of infection in your area, utilize the Fusarium Risk Assessment Tool just prior to flowering. It is available at http://www.wheatscab.psu.edu/ If a susceptible variety is planted and the risk of FHB is moderate to high, consider a fungicide application of Prosaro, Caramba, Proline, or Miravis Ace at Feekes Growth Stage 10.5.1 (early flowering, Figure 3) or within the first 4 day after Feekes 10.5.1.
Soybean seedling diseases are often the cause of reduced stands and can cause significant economic losses on an annual basis. Diseased seedlings are often less vigorous and severe stand loss may require replanting of affected areas. So far, this spring, the persistent wet weather we have been experiencing has created ideal conditions for the onset of early-season soybean seedling diseases. Diagnosing seedling diseases in the field can be difficult since the symptoms of various seedling blights are similar, and seedlings often decompose quickly. Since it’s too wet to plant, now is a great time to scout your existing emerged fields for stand issues.
Is caused by the fungus Rhizoctonia solani. The characteristic symptom of Rhizoctonia seedling blight is a reddish-brown lesion on the lower stem or hypocotyl, usually at the soil level. Lesions on the diseased stem appear sunken (canker-like) and dry, and can girdle the hypocotyl. 
The head is inside the leaf sheath giving it a swollen appearance. The flag leaf sheath and peduncle elongate and the developing head is pushed through the flag leaf sheath. Temperatures below 28 degrees Fahrenheit may cause damage to the developing head.
Don’t miss this year’s Conservation Tillage and Technology Conference March 11-12, 2025, (Tuesday-Wednesday) at Ohio Northern University, Ada, Ohio. Connect with other great farmers and CCAs, experience new ideas, and increase your net income.
Join us on February 27th for the 5th annual virtual Corn College and Soybean School presented by the Ohio State University Extension Agronomic Crops Team. The program will run from 9:00 AM to 4:00 PM and feature OSU Extension field and state specialists with updates and topics relevant for the 2025 growing season. CCA CEU credits will be available upon viewing the live presentations. Talks will also be recorded for later viewing on the Ohio State Agronomy YouTube channel, 
This past year, with support from Ohio Corn and Wheat through the Corn Check Off, we established a pilot corn deoxynivalenol (DON) hybrid susceptibility screening trial. The objective of this project was to identify hybrids with partial genetic resistance to DON. Use these results with caution because this is our first year of data. This trial was conducted at three locations across the state that represent different production regions: Apple Creek, Bucyrus, and South Charleston. While we had three different environments, the fact that the hybrids vary in maturity means that there is a chance that the weather was not conducive to ear infection and DON production by the fungus Fusarium graminearum during each individual hybrid pollination window. All locations had natural infection across all maturity groups, but to help increase the change of Gibberella ear rot (GER) development, and consequently, DON contamination of grain, we also inoculated plots at Bucyrus and Apple Creek. Since average DON contamination was not significantly different between inoculated and naturally infected plots at these two locations, the results are summarized, and hybrids are compared, by location. With a relative maturity spread of 18 RM, the pollination window at all 3 sites was 3 weeks from the time the first silks emerged until only brown silks were found.
As harvest approaches, its time to check our corn plants for stalk integrity. Time spent tin the field now, may pay huge dividends later this fall. As stalk tissue becomes compromised below the main ear the stalk may become brittle or weak and be prone to lodging.
Corn
Scouting
