Tillers (also called "suckers") are upright plant shoots that develop from special stem structures called crowns.
Crowns are found at or below ground level in certain plants. Because tillers do not come from the root system, they are essentially "branches" of the main stem. Not all plants have the ability to tiller, but some familiar crop examples are sorghum, wheat, and alfalfa, which is shown below. Notice the dense area at the top of the root where all of the shoots are beginning. (That's the crown )
Crowns allow perennial grasses/legumes to survive the winter (like fescue or alfalfa). For annuals, like sorghum or wheat, development of tillers from the crown is a response to "extra" resources in the field - light, water, nutrients, etc. Tillering is a plant's strategy for using all of the inputs at its disposal to produce more energy.
Tillering is desirable in some species, like wheat, and not as desirable in others, like corn. This is due to the different ways tillers develop in these crops and the structure of the plants themselves. Because corn is tall and bulky compared to wheat, those additional branches have a lot more to compete with in a corn field. Competition drains resources that the main stalk could have potentially used, because the tillers are now fighting for the same resources.
The big question is, will the tillers have something to show for those "stolen resources" at the end of the season, or are they just wasting them? That's where our research comes in.
So what makes a corn tiller more competitive? How can we predict if they will be good for anything? These are great questions, and some answers are (hopefully) coming soon!