How Creeping Bentgrass Cultivars Are Bred and Produced

Creeping bentgrass (Agrostis stolonifera) is widely used on closely mown golf turf, particularly putting greens. Its fine turf characteristics, tolerance of very low mowing and stoloniferous growth enable it to form the dense, uniform surfaces required for golf.

However, cultivars within the species can differ considerably. Characteristics such as shoot density, growth habit, disease tolerance and performance under environmental stress can all be influenced through breeding and selection.

Developing an improved cultivar is only part of the process. Creeping bentgrass also has exceptionally small seed, making the production of clean, high-quality seed particularly demanding.

These breeding priorities can be seen in the different characteristics of modern creeping bentgrass cultivars. Within ICL’s ProSelect portfolio, cultivars including MTV-1 Oakley, Riptide, Piranha and Memorial have been selected for different combinations of turf and environmental performance characteristics. The result is not one ideal creeping bentgrass, but cultivars suited to different growing conditions and management objectives.

Why creeping bentgrass breeding matters

Creeping bentgrass is naturally well suited to closely managed golf turf. It spreads through stolons – horizontal stems that grow across the surface and produce new roots and shoots at their nodes. This allows the plant to colonize surrounding areas and develop a dense turf.

But species alone does not determine performance. Individual creeping bentgrass cultivars can differ in characteristics that influence both the quality of the playing surface and how the turf responds to its growing environment.

Plant breeding aims to identify and combine useful characteristics and then evaluate whether they are expressed consistently enough to produce an improved cultivar.

For golf turf, this means breeding is not simply about producing a new creeping bentgrass. The objective is to develop cultivars with characteristics relevant to the demands placed on closely mown turf.

How are creeping bentgrass cultivars developed?

Traditional turfgrass breeding can involve selecting promising plants from genetically diverse material and crossing them with established cultivars. The resulting populations can then be evaluated and repeatedly selected for desirable characteristics.

This process allows breeders to explore genetic variation while progressively selecting plants that demonstrate the required turf characteristics.

Creeping bentgrass presents particular challenges, however. Its genetics and differences in ploidy make introducing material from wild populations more complicated than in some other turfgrass species. Potentially useful characteristics therefore have to be considered alongside the possibility of introducing characteristics that are undesirable in managed turf

Creeping bentgrass cultivars under evaluation at Rutgers Center for Turfgrass Science.

What are breeders selecting for?

The characteristics targeted by a breeding program depend on the intended turf environment and the performance required. For creeping bentgrass, important areas of selection include:

Disease tolerance

Creeping bentgrass can be affected by several turf diseases. Disease tolerance has therefore been an important breeding objective, with breeders selecting plants that demonstrate improved performance against relevant diseases.

Cultivar choice does not remove the need for appropriate turf management, but genetic disease tolerance can form part of an integrated approach to maintaining turf quality.

Shoot density and growth habit

High shoot density contributes to the dense, uniform turf required on golf greens.

Breeders have also selected for different growth characteristics. For example, ProSelect Riptide combines high tiller density with an upright, low-growing habit, illustrating how breeding within Agrostis stolonifera can influence the character of the resulting turf.

These differences matter because cultivars within the same species do not necessarily produce identical surfaces or respond to management in exactly the same way.

Environmental stress tolerance

Heat, cold, drought and wear can all place creeping bentgrass under stress. Breeding programs therefore evaluate plants under different conditions to identify cultivars capable of maintaining turf performance across the environments for which they are intended.

Cultivar characteristics can vary considerably. ProSelect Piranha, for example, has been selected for performance under heat and cold stress alongside disease tolerance and early spring green-up, while other cultivars place greater emphasis on different combinations of characteristics.

This is why environmental performance should be considered at cultivar level rather than assuming every creeping bentgrass will behave in the same way.

Why is creeping bentgrass breeding challenging?

Introducing greater genetic diversity can be valuable in plant breeding because it gives breeders access to a wider range of characteristics.

With creeping bentgrass, however, differences in chromosome number and ploidy can complicate this process. Introducing genetic material simply because it possesses one desirable characteristic could also introduce characteristics that reduce its suitability for high-quality turf.

This means breeding involves more than identifying an individual characteristic such as disease or stress tolerance. Plants also need to retain the wider combination of characteristics required for closely mown professional turf.

The result is a process of selection and evaluation rather than improvement of a single characteristic in isolation.

How is creeping bentgrass seed produced?

Once a cultivar has been developed, producing high-quality seed presents a different challenge.

Much of the world’s creeping bentgrass seed production is centered in Oregon’s Willamette Valley in the USA, where specialist growers produce seed for professional turf markets.

Creeping bentgrass seed is extremely small, with approximately 13 million seeds per kg. This makes contamination particularly difficult to address after harvest because unwanted seeds can be difficult to separate effectively from the bentgrass seed.

Weed management during production is therefore important. With limited chemical options available for weed control in creeping bentgrass seed crops, growers may use spot treatment and manual removal of contaminants throughout the growing season.

The original production information describes specialist growers inspecting and weeding fields five to ten times during the growing season, continuing until shortly before harvest.

Suggested image: Creeping bentgrass seed-production field or close-up of harvested seed.

Caption: Producing clean creeping bentgrass seed requires careful management throughout the growing season because of the species’ exceptionally small seed size.

Why does seed purity matter?

For professional turf managers, cultivar characteristics are only part of the seed-quality equation.

A breeder may have developed a cultivar for characteristics such as density, disease tolerance or environmental performance, but the seed supplied also needs to maintain appropriate standards of purity.

This is particularly important with creeping bentgrass because its very small seed makes removing contaminants after harvest difficult. Preventing contamination in the production field therefore becomes an important part of producing high-quality seed.

Breeding and seed production should consequently be viewed as connected stages: first developing the required genetics and then producing seed capable of delivering that cultivar to the turf manager.

From breeding to the golf green

Modern creeping bentgrass cultivars are the result of selection across multiple characteristics rather than improvement in one trait alone.

Disease tolerance, shoot density, growth habit and tolerance of environmental stresses can all influence how a cultivar performs. The relative importance of those characteristics will depend on the climate, surface, existing turf and management objectives.

This variation can be seen across ICL’s ProSelect creeping bentgrass portfolio, which includes MTV-1 Oakley, Riptide, Piranha and Memorial. Each represents a different combination of selected characteristics rather than simply another version of the same grass.

Understanding those differences is important when selecting seed. Choosing creeping bentgrass identifies the species; choosing the cultivar determines the particular combination of characteristics being introduced into the turf.

For more information on the species, its characteristics and how it compares with browntop bentgrass, see Bentgrasses: Characteristics, Uses and Performance.