Southern rust has now been confirmed in corn in 26 Nebraska counties. As we confirm more Nebraska counties with southern rust, it's important to know that the vast majority of rust reports have been sparse and no fungicide application was required. Continued scouting is urged, as injury can be critical to the grain-fill through dough stages.
Warm, wet conditions across Nebraska the past two weeks created optimal conditions for crop diseases. This update looks at identification and management of three diseases in corn: southern rust, which is expanding in the state, bacterial leaf streak, and diplodia, which is new to Nebraska.
As conditions heated up the last two weeks, the fungus causing phytophthora root and stem rot became active in irrigated fields and those fields that received significant rain over the past couple weeks. Growers are encouraged to scout for this disease and, if found, manage through seed selection and treatment for the next crop.
Southern rust has been confirmed in corn in 8 eastern Nebraska counties and growers are urged to scout vigilantly to schedule optimal timing of treatment, if needed. Most systemic fungicides can provide protection of leaves from future infections for 21-28 days.