A tassel contains about 1,000 individual spikelets, and each spikelet bears two florets.

By Jeff Burbrink
Extension Educator, Purdue Extension Elkhart County

Jeff Burbrink
Extension Educator, Purdue University Elkhart County

GOSHEN —The word “tassel” brings to mind different images for different people. The Israelites were instructed to make tassels to remind them of the commandments as they traveled through the desert. A few hundred years later, tassels were used to adorn European castles and property of royalty. In our modern era, tassels are still used to decorate garments and curtains, as well as to signify graduation from high school or college.

To a farmer or gardener, tassel takes on a different meaning. The tassel is the male portion of the corn plant, producing pollen to drop onto the silk of the corn, and thus pollenating the ear. Corn is one of many plants that has both male and female flowers on the same plant, a condition called monoecious by botanists.

A tassel contains about 1,000 individual spikelets, and each spikelet bears two florets. Each floret contains three anthers, which can be seen hanging from the tassel during pollination. All in all, there are about 6,000 pollen bearing anthers, ready to drop millions of pollen grains as the plant matures.

Pollen drop is a vulnerable stage for the corn plant. Extreme heat or drought can kill pollen, and severely cut the yield of your field corn or favorite sweetcorn. Fortunately, the plants have adapted to drop pollen over a period of several days, up to two weeks, which spreads the risk of heat and drought related failure.

Most pollen drops from the tassel in the morning hours, when temperatures are cooler. There is a secondary drop of pollen in the late afternoon or evening as temperatures fall. The anthers even adjust to rainfall. When the they are wet, the pores from which the pollen grains fall do not open, helping to minimize the amount of pollen washed directly to the soil.

The breeders of hybrid corn and sweetcorn varieties take advantage of the tassel to create the hybrids we plant the following year. A hybrid is the product of crossing plants of known characteristics, which produces seeds that have many useful features, such as high crop yields, disease or insect resistance or the sweetest sweet corn ever.

In seed fields, one of the parent plants is deemed the female. There are often four to six rows of female plants planted in blocks in the field. Their ears will be used to grow the seed for next year. Next to the female rows of corn, the male plants (those that provide pollen) are planted, usually in one or two rows.

When the tassels are beginning to form, the plants being harvested for the seed (the “female” plants) are detasselled, meaning the tassel is removed, which prevents self-pollination of the female plant’s ear. The “male” plants, those with the tassels remaining, drop their pollen, pollenating both the females in adjoining rows, and themselves. A few weeks later, the male rows are destroyed, for their seed is not desirable.  At harvest, only the ears of the female plants are carefully harvested, dried and bagged for next year’s growers.

If you live next to fields where hybrid corn is grown, you may be asked not to grow sweetcorn in your backyard. The pollen from just one of your plants can contaminate as much as three acres of hybrid corn if it reaches the female hybrids silk at the wrong time. It is not uncommon for the seed growers to provide gift cards or sweetcorn to neighboring gardeners. It’s just one way to provide a better-quality product for all those people and animals that like to eat corn.