Thomas G. Chastain
Tillers, rhizomes, and stolons are three types of branches produced by grass plants. All are stems that branch at some point from the crop’s mainstem or from other stems.
The tiller is an above-ground branch on a grass plant. Tillers are an important component of the crop’s shoot system and through carbon capture and partitioning, contribute to seed yield. As a tiller grows and develops, additional tillers can form in the leaf axils of that tiller. All grasses produce tillers.
Roots are also associated with each tiller. The crown is the part of the plant where the shoot system (tillers) meets the roots. If a tiller is separated from the rest of the parent plant, that tiller is capable of independent existence as each tiller can form its own root and shoot system and can become a new plant that is genetically identical to the parent plant.
Some tillers are induced to flower and thus bear inflorescences or groups of flowers. We often refer to these flowering tillers as fertile tillers and are the site of seed production in the grasses. Management practices that favor the production of fertile tillers typically will enhance seed yield of grass seed crops. Practices such as good nitrogen nutrition, post-harvest residue removal, and others increase fertile tiller production and seed yield.
Rhizomes are specialized stems which grow horizontally below the soil surface and eventually turn upward. At the point where the rhizome emerges from the soil, a new plant, genetically identical to the parent plant can be formed. Stolons are horizontal, above-ground stems. Like rhizomes, the stolon is capable of rooting and forming a new plant genetically identical to the parent plant.
Rhizomes or stolons are found in grasses with a creeping type growth habit such Kentucky bluegrass, creeping red fescue, bentgrasses, etc. Management practices that favor the production of rhizomes and stolons by the plant over tillers often lead to less flowering in grass seed crops and is accompanied by reduced seed yield.
