Below average temperatures this week have slowed crop growth. Most planting is complete and limited replant, mostly soy, has taken place. While most observations are focused on aboveground 2025 crop development, it is interesting to consider what is happening underground. While variation exists among hybrids and locations we can share several generalizations about corn root growth. The maximum rooting depth is largely determined by the depth of the groundwater table. Corn roots require oxygen to respire and survive, for this reason most corn root growth ceases once the water table (and saturated soil) is reached. Roots can be expected to extend or “meet” across 30-inch rows by the corn plant at V6 but has been reported in earlier stages in favorable growing conditions. The corn plants’ maximum root depth, which can reach six feet (if not limited by soil barriers) is normally attained by the blister or milk stage in the growing season. Maximum root depth can be helpful, but we are reminded that most of the root density is in the top two to three feet of the soil profile.
While scouting fields this week I am visually reminded of management suggestions shared by Extension Weed Specialists, including Dr. Aaron Hager, on the importance of preventing Waterhemp from reaching the stage of viable seed production. When allowed to do so, these prolific seed producing weeds can generate an impressive flush of weed seedlings the following year. Despite the cool week Burcucumber is getting an early start and has been noted as well. Evaluate stand and post herbicide efficacy in both corn and soy fields in the upcoming weeks.