Results form plots other than at the Corn Illustrated site tended to show a big increase in stalk and root lodging last fall for fields planted relatively late. The same two hybrids planted in early May in similar tests vs. the same two hybrids planted in the last week of May received very different lodging scores in some tests.
Later-planted corn tended to lodge more. In one trial in northwest Indiana, lodging percentages rose well above 20%, and occasionally above 40%. Those percentages were much higher than notes at other locations for the same hybrids planted at more normal planting dates. Ear drop, however, wasn't a concern. Also, the plots where these lodging numbers were recorded were harvested relatively late, in early November.
Dave Nanda, president of Bird Hybrids, Tiffin, Ohio, and based in Indianapolis, is not surprised at these results. Late-planting tends to favor more lodging, especially if the corn is left in the field relatively late in the season. Planting late tends to lead to a later-than-normal harvest in most situations since it takes longer for those late-planted hybrids to reach acceptable moisture levels in the fall.
The increase in lodging is partially due to responses in how stalks develop based upon planting date, Nanda notes. The same hybrid planted late in the season, say in late May or early June, is likely to grow taller with smaller stalk diameter than plants of the same hybrid planted early to even on time. It's a physiological response to the environment, Nanda notes. In this case, the environment is date of planting.
The taller the corn and smaller the stalk diameter, the more susceptible the corn is to strong winds. The longer it is left in the field to dry, the more likely it is that fall storms will knock down a higher percentage of the corn.
Stalk rot also factors into the equation. Corn left in the field longer may tend to develop reasonably high amounts of stalk rots, leading to more stalks that fail the 'push' test. The push test involves simply walking down the rows at harvest and pushing on plants. Those that don't spring back are typically infected by stalk rot. They're also counted as lodged plants when counts are made in research trials.
The best advice is to pick hybrids that tend to remain healthy and have good lodging scores, then plant as early as possible, Nanda concludes.