Premature Kernel Sprouting in Corn
Bob Nielsen, Extension Agronomist, Department of Agronomy, Purdue University
Vivipary, the premature germination or sprouting of corn kernels on the cob prior to harvest, is not a common problem in Indiana but sometimes can be serious enough to warrant attention from growers. Germination of mature corn kernels on the cob prior to harvest is most likely to occur when reasonably dry kernels ( less than about 20 percent grain moisture content) are re-wetted, especially when temperatures are warm. Consequently, the common situation for vivipary to occur is the combination of dry grain, upright ears on the plants, and rainfall that is "captured" by the husk leaves of the upright ears. The result can be sprouted kernels near the butt of the ear. The likelihood of viviparous germination occurring on upright ears with grain at higher moisture contents is typically much less than for dryer grain. Another common situation where vivipary occurs is when ears are lying on or near the soil surface due to severe stalk breakage or lodging. That proximity of the ears to moist soil allows a similar re-wetting of the kernels and dramatic germination of kernels on the cob much like we would typically see the following spring.
On the rare occasion when viviparous germination occurs throughout a field to a large enough degree, overall grain quality can deteriorate enough to cause problems with drying and storage of grain. Another consequence is the potential increase in the percentage of "broken corn and foreign material" in affected grain delivered to the elevator that may result in significant grain price discounts to the grower.
For more information, see my article on vivipary at http://www.kingcorn.org/news/timeless/Vivipary.html