(2018) Turfgrass Trends for Changing Times

Dr. Grady Miller, Professor and Extension Specialist, Co-Director, Center for Turfgrass Environmental Research & Education, NC State University

Dr. Richard Linton, Dean, College of Agriculture and Life Sciences, NC State University

https://vimeo.com/305170897

“The Evolving Technology of Plant Protection”

As a small segment of the crop protection business, the future of turfgrass protection will be driven by the future of crop protection. The crop protection industry is influenced by many external factors, including evolving production methods, commodity prices, climatic conditions, geopolitical factors, regulatory processes, and public perception. Successful crop protection companies will adapt evolving technology to meet market opportunities and customer demands. With so many external influences, it is difficult to predict the future, but current trends provide some clues. Major crop protection companies are now more diversified in crop genetics, abiotic stress management, biologicals, and precision farming, with significant R&D focused on integrated solutions. There is still a need for traditional crop protection products, and new technology is accelerating the discovery and optimization of powerful new chemistries. We will discuss how these and other trends may impact the turfgrass industry, with particular focus on research needed to ensure that new tools can be effectively adopted.

https://vimeo.com/305168718

“Natural Turfgrass: Public Perception, Policy and Regulation”

Natural turfgrass has many uses and benefits in urban environments where it captures rainfall and stormwater runoff, moderates temperatures, filters urban pollutants, provides a safe playing surface for children, and more. Perennial turfgrasses are some of the most adapted plants for use in urban environments yet their use is often discouraged or even limited by regulatory agencies, modeling codes, mandatory standards, and rating systems. While these systems are well-intentioned and primarily designed to reduce water use, their design and implementation often do not fully account for new irrigation technologies, plant breeding advances in drought tolerance, proper site construction, and the role that natural turfgrasses, like all plants, play in otherwise concrete, plastic, and artificially constructed urban environments. This session will highlight public and regulatory perception using survey and other data as a framework for discussing the current and future role of natural turfgrasses in urban and suburban environments. It will also highlight consumer and market research that Turfgrass Producers International is conducting to determine what factors influence people’s views of natural turfgrass and its alternatives.

https://vimeo.com/305166890

“Standing between order and chaos: how the turf industry can capture the imagination of a public that doesn’t understand their value”

The turf industry is in the rare position of finding the perfect balance between the unexpected beauty of the chaotic natural world and the pristine elegance of perfectly ordered cultivated turf.  In this talk, Vance Crowe will discuss why this balance is so complicated for the public to understand and what the industry must do to capture the public’s attention and re-write the narrative of the value of this field of research and industry. The talk will discuss why consumers vastly over-estimate what they know and how they form their opinions as a function of the tribes they are in.  Vance will highlight the work of the Consumer Engagement department at the newly merged Bayer company, which helped to redefine the value of modern agriculture and what they learned through hundreds of conversations about complex topics like genetic engineering and crop protection. The talk will also include advice for engaging with people that have strongly held positions so that you can learn from your critics and participate in positive and productive conversations.  Vance will specifically highlight the Dunning-Kruger Effect and discuss the technique of “steel-manning” your critic’s arguments. 

https://vimeo.com/305164059

• Dr. Rongda Qu, Professor (Turfgrass Molecular Biology), NC State University

“Engineered disease resistance and drought tolerance in turfgrasses”

Turfgrasses are often suffered from environmental stresses, such as fungal diseases and drought. Thus developing new cultivars resistant to these stresses is a very important breeding goal. In addition to the conventional breeding approaches, we now can use genetic engineering to introduce a single resistance gene, foreign or domestic, to achieve the goal. There are two major methods to deliver the DNA: using “gene gun” or Agrobacterium-mediated approach. We then employ tissue culture approach to obtain transgenic plants. One target disease is the gray leaf spot (Magnaporthe grisea). We introduced the bacteriophage T4 lysozyme gene into tall fescue and obtained transgenic plants resistant to this disease. For resistance to brown patch disease (Rhizoctonia solani), we transformed tall fescue with a gene encoding a small antimicrobial protein isolated from a shrimp species. Moreover, we used an approach called “RNA interference” or “RNAi” by introducing double-stranded RNA of fungal essential genes to suppress fungal growth, and obtained transgenic plants resistant to the brown patch. Furthermore, we delivered a domestic drought-inducible gene into perennial ryegrass and obtained transgenic perennial ryegrass plants with improved drought tolerance. Future applications of GMO in turfgrass breeding will be discussed.

• Dr. Charles Peacock, Professor (Turfgrass Management), NC State University

“Use of UAV Multi-spectral Digital Images in Assessing Turfgrass Health”

Use of digital images taken using multispectral reflectance data recorded from Unmanned Aerial Vehicle (UAV) platforms, to measure turf quality, color, and nitrogen (N) uptake is a novel application within agronomy. The platform is able to fly at low altitudes, providing high-resolution measurements which allow precise prescriptions. Objectives of this study were to: 1) Correlate Normalized Difference Vegetation Index (NDVI) values created from multispectral data to those recorded with traditional ground based NDVI sensors and 2) Correlate these UAV-based NDVI values with turf quality and color measurements by experts along with plant-based N-levels determined from lab work. At all altitudes using a multispectral camera, NDVI measurements tend to correlate well with color and N, but not turf quality for the pre-clipping status. In a post-clipping status, there are generally lower correlations between NDVI and color, turf quality, and N. For the correlation between ground and UAV based measurements, NDVI values correlate well on one date post-clipping at 30 and 45 m altitudes while this is not the case for another date where pre-clipping NDVI values correlate well while the post-clipping values do not. As a result of the correlation differences between pre- and post-clipping status, there is evidence to support that clipping status impacts the correlation of NDVI with color and N. Data for ground versus UAV NDVI measurements are in contrast to one another on different data collection dates and the correlation between the two platforms is unable to be established with this study.

• Lee Butler, Extension Specialist (Turfgrass Pathology), NC State University

“Turf Disease Diagnostics: The Bridge Between Extension and Research”

The Plant Disease and Insect Clinic (PDIC) at NC State University was founded in the 1950’s in response to the demand for diagnosis of tobacco diseases. In 1968, NC State hired Dr. Leon T. Lucas as a forage pathologist. He started diagnosing diseases of turfgrasses in the 1970’s and eventually became a full-time turfgrass pathologist in 1980, serving in this role until the late 1990’s. Since 1999, NC State has seen Dr. Henry Wetzel, Dr. Lane Tredway, and currently Dr. Jim Kerns serve in this role. In 2005, Dr. Tredway and Lee Butler started the Turf Diagnostics Lab (TDL), which is currently housed within the PDIC. In the early Lucas years, most of the samples were from home lawns via county extension agents, however this shifted to mostly golf courses in the mid-80’s and has remained the same ever since with around 70% of all samples coming from golf courses from all over the United States. The TDL averages around 700 samples per year, with submissions from creeping bentgrass putting green being the most common between 2005-2016. In the 2017, ultradwarf bermudagrass putting green samples took over the top spot for the first time due to the widespread industry movement towards these grasses for putting surfaces, particularly in the southeastern United States. The TDL is on the leading edge of discovering the most common chronic issues that are plaguing turfgrass managers. This helps determine graduate student projects, fungicide efficacy trials, and topics for educating future turfgrass managers. Additionally, the TDL serves as an alarm for the emergence of new diseases, therefore allowing us to respond in a timely manner to provide growers with the best research-based management strategies possible.

https://vimeo.com/305160628

https://vimeo.com/305158524

• Ray McCauley, PhD student, Turfgrass Management

“Shallow Soil Compaction Following Fraise Mowing”

Fraise mowers are aggressive tractor-mounted implements that can remove plant and soil material from 0 to 5 cm (0 to 2 in.) depths. Compaction from routine traffic in turfgrass systems is usually confined to the surface 7.6 cm (3 in.) of the soil profile, which overlaps with fraise mower functional depths. This study was conducted to evaluate fraise mowing as a viable cultivation method to remove surface compaction beneath hybrid bermudagrass. A trial was conducted in 2018 on a sandy soil in Jackson Springs, North Carolina. Plots were subjected to 0, 20, or 30 passes with a modified Baldree traffic simulator, all plots were then fraise mowed at 2.5 or 5 cm depths, and measurements were made following traffic simulation and fraise mowing. Soil hardness increased with the number of games simulated . All traffic levels had similar soil hardness values after fraise mowing. Trafficked treatments (20 and 30 passes) had lower soil hardness values after fraise mowing, and non-trafficked control treatments had a 29% increase in soil hardness after fraise mowing.  However, volumetric water content was 43% less at sampling after fraise mowing, which may have increased non-trafficked control soil hardness values. Saturated hydraulic conductivity (Ksat) decreased 32% after fraise mowing at the 2.5 cm depth and remained static at the 5 cm depth (5.6 cm hr-1) after fraise mowing. Lower soil hardness values following fraise mowing in trafficked plots indicates the potential for compaction relief.  However lower Ksat rates at 2.5 fraise mowing depth may indicate potential soil crusting. This trial will be repeated in 2018.

• Jessica Brown, MS student, Turfgrass Breeding and Genetics

“Improving the Efficiency of Selection for Freeze Tolerance in Zoysiagrass”

Zoysiagrasses are warm season, vegetatively propagated turfgrass species with general tolerance to a variety of abiotic stresses such as drought, shade and salinity. Though the species are increasing in popularity in the southeastern US, they are commercially limited to the northern limits of the transition zone due to their limited freeze tolerance in comparison to cool-season grasses. Traditional breeding for freeze tolerance in these species’ has had limited success, with Meyer, released in the early 1950’s, remaining the most freeze tolerant cultivar to date. The objectives of our research are to elucidate the genetic and metabolic components responsible for freeze tolerance in order to identify selection targets that might facilitate and speed up breeding of freeze tolerant cultivars. A mapping population generated from a cross of Meyer (freeze tolerant) x Victoria (freeze susceptible) was utilized to develop a SNP-based high density linkage map. Additionally, the population was evaluated for freeze tolerance under field conditions and in lab-based freezing tests. Freezing survival data were used in combination with the linkage map for QTL analysis in order to identify genomic regions associated with freezing tolerance. Furthermore, the mapping population was evaluated under no acclimation and cold acclimation for differentially expressed proteins. Proteomic analysis identified several proteins of interest associated with cold acclimation, a critical process in freezing tolerance. Further investigation of these proteins in conjunction with QTL analysis might help us identify candidate genes controlling freezing tolerance. Markers strongly associated with these genomic regions will be utilized for the development of elite Zoysiagrass breeding materials via marker assisted selection.

• Allison Anthony, PhD student, Turfgrass Pathology

“Diversity and SDHI Insensitivity in Clarireedia jacksonii ”

Previously known as Sclerotinia homoeocarpa, a group of species in the genus Clarireedia are fungi which cause the dollar spot disease on turfgrass. This disease is a significant problem for highly maintained turfgrass and the most costly to control globally. In the summer of 2016, there was an observed failure of SDHI fungicides to control C. jacksonii in experimental plots. After testing multiple types of media of different strengths, traditional amended-media screening has failed to show differences in sensitivity which have been observed in the field. To establish isolate-based sensitivities, in vivo fungicide trials were performed. 15 isolates (11 collected from “resistance” event at NCSU research plots, 4 from various locations with no field observed resistance) were chosen to inoculate 8 week-old ‘ Penn-A1’ creeping bent grass grown in conetainers. Inoculations took place the day after plants were sprayed with rates of boscalid, penthiopyrad, and fluxapyroxad that were used in the original trial which experienced the resistance event. Infested rye grains were used for inoculations and the conetainers kept in humidified growth chambers in a completely randomized block design. The infection centers were measured and disease severity was taken on day 5 when significant amounts of disease had developed. From this screening, the control isolates were numerically the most SDHI sensitive isolates and a few isolates were statistically insensitive to some of the SDHI fungicides. This suggests that in vivo screenings may be more informative than in vitro screenings when it comes to this particular fungus and class of fungicides. The observed insensitivities being only a small portion of collected isolates leads to the question of how much of the “resistance” event really was a result of a truly insensitive population. Further investigation to other contributing environmental factors is necessary to establish the cause of the chemical failure event.

• Laney McKnight, MS student, Pesticide Fate and Behavior

“Pesticide Phytoremediation Capacity in Terrestrial Plant Species”

Previous research has shown plant-pollutant bioremoval capacity may differ across species and/or compounds. Phytoremediation of pesticides has been minimally investigated with plant species adapted to environmental conditions common to the southeast United States. The goal of this research is to expand upon current knowledge to identify plant species best suited to mitigate pesticides off-target transport prior to establishing and/or renovating riparian buffers or stormwater wetland areas in urban and rural settings. A selection of three terrestrial NC native plant species (switchgrass, blueflag iris, and broomsedge) were chosen based on prior metal phytoremediation studies and the plants’ tolerance to commonly used herbicides. The plants were potted into unique containers which were then treated with either atrazine, azoxystrobin, or imidacloprid.  The soil, above ground vegetation, and below ground vegetation were analyzed 28, 56, and 112 days after treatment.  Switchgrass, blueflag iris, and broomsedge were found to continuously remediate all three pesticides throughout the 112 day period.  Azoxystrobin was found to be remediated at a higher rate than atrazine or imidacloprid.  Future studies will include three aquatic plant species to develop a list for pesticide mitigation areas.  This research will aid the construction of a mitigation plan for urban and rural landscapers to help prevent the possible risk of off-target pesticide movement.

https://vimeo.com/305155841