Pro Farmer Editor Chip Flory last week noted that some "weird" diseases were popping up in the Corn Belt, with one of those being rootless corn syndrome. Since his blog post, curiosity about the syndrome has escalated and a Pioneer Hi-Bred agronomist pointed out that several factors contribute to it, including dry surface soils, shallow planting depths, sidewall compaction and cloddy soils.
A Pioneer Hi-Bred agronomy update dated May 24, 2007, states planter operation in wet soil conditions can result in pockets in the field where the seed trench was not closed properly and/or significant seed furrow sidewall compaction occurs.
• As the corn plant matures, nodal roots must form above the seed and proliferate into the surrounding soil profile to absorb water and nutrients.
• Roots will take the path of least resistance, as long as they have oxygen and water to grow in. Therefore, roots will likely proliferate within and, downward out the bottom of the seed furrow, resulting in a tomahawk shaped root system.
• The upper soil profile is not explored for nutrients, which could result in reduced yield.
• Lack of support for the plant could reduce standability.
It goes on to explains that in areas of fields where severe seed furrow trenching has occurred, air in the furrow can cause tissue to dry out, inhibiting nodal root growth due to lack of moisture.
One solution for minimizing the potential impact of rootless corn syndrome is through adequate moisture (either timely rain events or irrigation when possible) to stimulate nodal root development. Additionally, producers could potentially consider cultivation if management practices are open to this option, states the bulletin.
• Cultivation to open the surface and cause aeration in the profile stimulates root growth. Consider this carefully, as the profile may already be dry due to environmental conditions in the past 7-10 days. When plants are large enough, cultivation to move soil around the base of the plant will help stimulate Brace Root formation. This will improve plant support for better standability later in the season.