Soybean Growth

Red Crown Rot: What Ohio Soybean Growers Need to Know

Article by: Sarah J. Noggle, Extension Educator, Agriculture and Natural Resources, Paulding County

As the 2025 growing season begins, it’s important for Ohio soybean farmers to be aware of a potential new threat: Red Crown Rot (RCR). While this disease has not yet been confirmed in Ohio, it has been identified in nearby states, including Kentucky and Illinois, which means vigilance is key.

What is Red Crown Rot?
Red Crown Rot is a soilborne fungal disease caused by Calonectria ilicicola. It can be easily confused with other common soybean diseases like Sudden Death Syndrome (SDS) and Brown Stem Rot (BSR) because of similar yellowing between the leaf veins (interveinal chlorosis). However, a key identifying feature of Red Crown Rot is the presence of brick-red fungal structures at the base of the stem and crown, especially noticeable under wet conditions.

Why Does It Matter?
Red Crown Rot can lead to significant yield losses and is challenging to manage once it becomes established in a field. Understanding how to recognize early symptoms and differentiate it from other diseases is critical for minimizing its impact. Continue reading Red Crown Rot: What Ohio Soybean Growers Need to Know →

Soybean Vegetative Growth Stages- VC vs V1

Article by Laura Lindsey

Stage VC - Definition: Fehr and Caviness (1977)- Unifoliolate leaves sufficiently unrolled, so the leaf edges are not touching Pederson (2009)- Unifoliolate leaves unrolled sufficiently, so the leaf edges are not touching

Stage VC – Definition: Fehr and Caviness (1977)- Unifoliolate leaves sufficiently unrolled, so the leaf edges are not touching Pederson (2009)- Unifoliolate leaves unrolled sufficiently, so the leaf edges are not touching

Across the state, soybean growth and development is variable, ranging from early vegetative stages to flowering. However, there has been some confusion regarding the identification of the VC and V1 growth stages. This confusion is mostly due to two definitions of V1…that actually mean the same thing. The Fehr and Caviness Method (1977) is based on the number of nodes that have a fully developed leaf, whereas Pederson (2009) focuses more on leaf unrolling so that the leaf edges are no longer touching. The VC definition for both methods is the same, but the differences start to appear between the methods at V1. Fehr and Caviness define V1 as “fully developed leaves at unifoliolate nodes,” which also means that there is “one set of unfolded trifoliolate leaves unrolled sufficiently, so the leaf edges are not touching.” This second definition is common in extension publications (Pedersen, 2009). Continue reading Soybean Vegetative Growth Stages- VC vs V1 →