By Scout Nelson
In Minnesota, the agricultural landscape is facing new challenges as corn and soybean diseases, typically seen in southern states, start to appear. Dr. Dean Malvick, an Extension plant pathologist, and Claire LaCanne, an Extension educator-crops, recently explored these issues during the Strategic Farming: Let’s talk crops session, focusing on how to tackle both emerging and known diseases in 2024.
Corn diseases like Gray Leaf Spot (GLS) and Northern Corn Leaf Blight (NCLB) have been topics of concern. GLS, favored by high humidity and warm temperatures, is less prevalent in Minnesota compared to southern regions but could pose a greater threat with wetter, humid summers.
NCLB, more widespread in Minnesota, grows in cool, wet conditions, though it rarely impacts yield significantly. Strategies for managing these diseases include planting resistant hybrids and applying fungicides when necessary.
Stalk rots present a more complex challenge, with multiple pathogens contributing to the issue. Techniques to combat stalk rots involve reducing stress on corn plants and minimizing leaf disease. Anthracnose, Gibberella, Fusarium, and Physoderma stalk rots are among the primary types detected in the state.
An emerging threat, tar spot, first identified in southeastern Minnesota in 2019, has shown development under drier conditions than expected. This insight shifts understanding about the disease's requirements, emphasizing the need for careful scouting and possible fungicide application if the disease surpasses a 5% severity threshold.
Southern rust, another emerging concern, has yet to cause significant problems recently but warrants monitoring, especially in August when it has the potential to become more prevalent.
For soybean farmers, diseases like Frogeye Leaf Spot (FLS) and White Mold continue to be significant. FLS, increasingly common since 2017, can cause substantial yield losses and requires careful fungicide management due to resistance issues. White Mold, a longstanding issue, benefits from cool, wet conditions, with management focusing on reducing planting density and selecting resistant varieties.
The threat of Soybean Cyst Nematode (SCN) and the potential rise of Charcoal Rot, exacerbated by drought conditions, underscore the importance of proactive disease management. While SCN has resisted significant control from seed treatments, ongoing research aims to better understand how to mitigate its impact.
These discussions, part of the 2024 session of Strategic Farming: Let’s talk crops, underscore the dynamic nature of crop disease management in Minnesota. As the state's agricultural community navigates these challenges, the expertise and guidance from specialists like Malvick and LaCanne are invaluable in ensuring the health and productivity of Minnesota's crucial corn and soybean crops.
Photo Credit -gettyimages-dszc
Categories: Minnesota, Crops, Corn