Posted 23 August 2023 by AusGAP

The science behind drought tolerant turfgrass varieties

The science behind drought tolerant turfgrass varieties

Drought is a growing concern in many regions of the world, and this is a particularly true area for areas that are dedicated to turfgrass. In the realm of landscaping, commercial spaces, and sports fields, the demand for drought tolerant turfgrass varieties has increased significantly. With the increasing frequency and severity of drought conditions and El Nino looming for Australia, it is more important than ever to explore drought tolerant turfgrass varieties that can help reduce water usage while still maintaining the desired appearance.

What makes turfgrasses more drought tolerant than others?

Warm season turfgrasses are naturally adapted to thrive in regions with hot dry summers and mild winters. Their unique genetic makeup allows them to enter dormancy during harsh conditions, such as extended drought periods. During dormancy, warm season turfgrasses conserve energy and water, which enables them to survive prolonged dry spells. However, not all warm season varieties exhibit the same level of drought tolerance.

What is the most drought tolerant warm season turfgrass?

Among the array of warm season turfgrasses, TifTuf Hybrid Bermuda has emerged as a top performer and has become the standard when it comes to drought tolerance. Developed through rigorous research and breeding efforts, TifTuf has set new benchmarks for sustainability and water conservation in the turfgrass industry. The drought tolerance of TifTuf Hybrid Bermuda is deeply rooted in its genetic composition. This variety inherits specific genes that regulate water use efficiency and stress tolerance. Compared to traditional turfgrasses, TifTuf has demonstrated an ability to survive with up to 38% less water and is genetically assured through the AusGAP program within Australia.

How are drought tolerant turfgrasses bred?

Creating drought tolerant turfgrass varieties is a complex and intricate process that involves meticulous breeding techniques and extensive research. Turf breeders play a pivotal role in developing new cultivars with improved drought tolerance, water use efficiency, and overall performance and here are some techniques utilised when breeding turfgrasses:

  • Selecting plants with desirable traits: The first step in breeding drought tolerant turfgrass varieties is selecting the parental plants. Turf breeders look for existing turfgrass varieties or wild turfgrass species that exhibit favourable traits related to drought tolerance. These traits may include deep root systems, reduced water loss through transpiration, efficient water uptake, and the ability to maintain photosynthesis under drought stress.
  • Controlled cross population: Once the ideal parental plants are identified, turf breeders perform controlled cross pollination to create new hybrids. The goal is to create genetic diversity that may yield superior drought tolerant traits in the spring.
  • Evaluating and selecting promising offspring: After the cross pollination, the turf breeders evaluate and select the offspring based on specific criteria including drought tolerance, growth rate, disease resistance, colour, texture, overall performance. The offspring undergo rigorous testing under various environmental conditions, including simulated drought stress, to identify those that exhibit the most promising drought tolerant characteristics.
  • Utilising molecular techniques: Developments in biotechnological breeding techniques have advanced the turfgrass breeding process. Turf breeders now have access to tools such as marker assisted selection and genomic selection. These techniques allow them to identify specific genes associated with drought tolerance and other desirable traits more efficiently. By targeting these genes, breeders can accelerate the development of drought tolerant turfgrass varieties.
  • Iterative breeding and selection: Turfgrass breeding is an iterative process that can involve multiple cycles of cross pollination, evaluation, and selection. Through each cycle, breeders refine the genetic composition of the new variety, gradually enhancing its drought tolerance and overall performance. This iterative approach allows for continuous improvement and the development of turfgrasses that outperform their predecessors.
  • Field testing and real-world performance: Before releasing a new drought tolerance turfgrass variety to the market, extensive field testing is conducted. These trials assess the variety’s performance under various real-world conditions, ensuring it meets the desired standards for drought tolerance, aesthetics, and playability. Only after passing these tests successfully is the new variety made available to the public however, this can take decades.

What technological advancements other than turf breeding help with drought stress?

In addition to breeding and genetic improvement, advances in irrigation technology are also playing a critical role in the conservation of water aiding drought tolerant turfgrasses. New, more efficient irrigation systems allow turfgrass managers to apply water precisely and only when it’s needed, reducing waste and conserving water. Another method is through evapotranspiration controllers, where water loss from the soil is measured through evaporation and plant transpiration to regulate irrigation schedules. By factoring in the water lost due to weather conditions and plant needs, these controllers can precisely determine the irrigation requirements of the turfgrass. This data driven approach ensures that the turf receives the right amount of water, reducing water waste and maintaining optimal plant health.

The breeding of drought tolerant turfgrass varieties is a blend of scientific expertise, patience, and innovation. Turf breeders harness the power of genetics, modern biotechnology, and environmental testing to develop grasses like TifTuf Hybrid Bermuda. These newly developed turfgrasses contribute significantly to sustainable practices, water conservation while withstanding the challenges posed by weather extremes.