Source: P. Thomison, OSU
Symptoms:
Kernels are absent or present in limited numbers in the basal portion of the ear. Aborted kernels absent in barren areas at the base of the ear.
Causes:
The lack of kernel fill at the base of ears may occur because the basal silks emerged before pollen shed began. Silks may have also become desiccated due to severe water stress and high temperatures adversely affecting silk receptivity to pollen. If pollen was available, the silks may have been selectively clipped by rootworm beetles. Basal kernels are unlikely to abort since they are closest to the photosynthates supplied by the plant.
Management:
Follow recommended guidelines for minimizing crop stress, including maintaining appropriate soil fertility, adjusting planting depth with varying soil conditions, and selecting adapted hybrids and seeding rates consistent for soil yield potential and date of planting. Avoid planting too early in wet soils. Minimize weed competition with effective herbicide application and/or timely cultivation.
References:
Abendroth, L. 2005. Examine corn ears now for clues to earlier stresses. Univ. of Nebraska Extension Crop Watch (September 16, 2005). Available at http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1301&context=cropwatch [URL verified 3/28/2019].
Nielsen, R.L. 2016. Tassel Emergence and Pollen Shed. Corny News Network, Purdue Univ. [On-Line]. Available at http://www.agry.purdue.edu/ext/corn/news/timeless/Tassels.html [URL verified 3/28/2019].
Nielsen, R.L. 2007. Silk Development and Emergence in Corn. Corny News Network, Purdue Univ. [On-Line]. Available at http://www.kingcorn.org/news/timeless/Silks.html [URL verified 3/28/2019].