Turfgrass Field Day

1. Evaluation of South African bermudagrass for shade and drought tolerance

This research will evaluate nine bermudagrass germplasm accessions collected in South Africa for their ability to grow under low light intensity. These accessions were collected from areas under severe shade and are expected to have some level of genetic shade tolerance. A 100 ft x 100 ft shade structure will be established at the Turf Field Laboratory in order to evaluate these materials along with three standard cultivars (Celebration, Tifway 419, and TifGrand) under two levels (60% and 80%) of shade. Data will be collected at 21 day intervals on rate of establishment under shade, leaf color, and for common adaptive responses of plants to low irradiance such as in creases in leaf-area ratio, leaf-to-stem mass ratio, and stem length, and decreases in specific leaf weight, plant dry weight, and root growth relative to shoot growth.

Additionally, a field test was established at the Sandhills Research Station in June 2009, in order to evaluate these materials for their ability to sustain growth and maintain color under no additional irrigation.

Treatments:

Shade Tolerance Test:

• A 100 ft x 100 ft shade structure will be established at the Turf Field Laboratory in order to evaluate these materials along with three standard cultivars (Celebration, Tifway 419, and Tifsport) under two levels (60% and 80%) of shade.
•  The design will be a split plot with levels of shade as the main plot and genotype as the sub-plot.
•  Data will be collected at 21 day intervals on rate of establishment under shade, leaf color, and for common adaptive responses of plants to low irradiance such as in creases in leaf-area ratio, leaf-to-stem mass ratio, and stem length, and decreases in specific leaf weight, plant dry weight, and root growth relative to shoot growth.

Drought Tolerance Test:

• A field test was established at the Sandhills Research Station in June 2009, in order to evaluate the same nine South African Bermudagrass accessions (along with checks Celebration, Tifway 419, and Tifsport) for their ability to sustain drought.
•  The design is a randomized complete block design with four replications.
•  Plots will be subjected to soil dry-down periods when rainfall is not forecasted. At the beginning of each dry-down the soil will be well irrigated and then irrigation will be withheld. During this drought stress periods data will be collected on leaf firing and wilt incidence. Additionally, data will be collected on root length and weight, and turf quality and color.

RESULTS (PDF)

RESULTS (PDF)

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2. Cultural practices to reduce bentgrass summer stress

This research study examines a series of cultural programs that can aid in reducing summer stress on creeping bentgrass putting greens. Each program consists of a different nitrogen rate, soil moisture content and cultivation practice. Previous research has brought a better understanding of the impacts of each practice individually. The next step and focus will begin on the combined and cumulative affects of an entire cultural program.

Additional research will examine the dynamics of organic matter build-up and decomposition in USGA putting greens. With the cultural inputs already in place, the rate at which organic matter builds in the system can be observed. Measuring microbial biomass will demonstrate the importance a healthy abundant microbe population plays in the breakdown of organic matter. Better understanding of this equilibrium is a vital and necessary component for the overall health of a turfgrass system.

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4. Evaluation of 113 tall fescue cultivars

These 113 tall fescue cultivars are part of the 2006 National Turfgrass Evaluation Program (NTEP) trial. This trial is duplicated in 28 locations across the U.S. Of the 113 cultivars, 39 were commercially available in the US in 2008. These grasses are being rated for turfgrass quality, genetic color, leaf texture, seedling vigor, density, cover, winter color, stem rust and brown patch incidence. This trial is a 5-year study.

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5. Nitrogen rate and mowing height effects on turfgrass quality and divot recovery of several new zoysiagrass cultivars

This study is designed to identify superior fine and coarse textured zoysiagrass cultivars well adapted to North Carolina. The objectives are: 1) to characterize a general response (color, density, turf quality, winter color, thatch accumulation, and disease incidence) of the Zoysia matrella and Zoysia japonica species to varying combinations of N fertility and mowing height treatments, 2) identify superior fine and coarse textured cultivars for use in North Carolina considering the potential for winterkill, and 3) establish appropriate mowing height and fertility recommendations for each of the cultivars studied.

Diamond, Pristine, Cavalier, and Zeon are managed for high-end use such as that found on tees, collars, and fairways. Study is evaluating mowing heights of ¼” and ½” and N rates of 1.5, 3.5, and 5.5 lb N per 1000ft-2. Empire, Palisades, Ultimate, and JaMur are managed for use for medium to moderate levels such as that found in landscapes, athletic fields or golf course roughs. These grasses are mowed at 1” and 2” with the same N rates as mentioned for the fine-textured zoysiagrasses. Data collected include cold tolerance, color, density, divot recovery, disease incidence, spring green-up.

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6. Effects of athletic field paint on turfgrass photosynthesis and transpiration

RESULTS (PDF)

RESULTS (PDF)

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7. Evaluation of national warm-season trials: Bermudagrass, zoysiagrass, and St. Augustinegrasses

Warm-season grass evaluation consists of several NTEP trials which include eleven zoysiagrass cultivars (1 seeded and 10 vegetative), thirty-three bermudagrass cultivars (27 seeded and 6 vegetative) and six St. Augustinegrasses. These grasses were fully grown-in in 2008 and were monitored for establishment, color, texture, fall color, spring green-up, disease incidence, shear strength, and wear tolerance. Smaller trials were initiated to evaluate three seashore paspalum cultivars and moderate blocks of two new centipedegrasses were plugged in fall 2008. Portions of the centipedegrass block did not survive the winter due to the late planting.

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8. Influence of management practices on Diamond zoysiagrass and Mini-Verde bermudagrass golf greens

Ultradwarf bermudagrasses such as ‘Mini-Verde’ are becoming more widely used on golf greens in the southeastern United States. They provide a comparable putting surface to creeping bentgrass golf greens and are less expensive to maintain. ‘Diamond’ is a fine textured zoysiagrass that has recently been considered for use on golf greens. It has good shade tolerance and can withstand low mowing heights for extended periods. However, there is limited scientific data regarding the management of ‘Mini-Verde’ bermudagrass and ‘Diamond’ zoysiagrass golf greens in the transition zone. This research will provide turfgrass managers in the southeastern United States with valuable information about the influence of N rate, verticutting, and topdressing on maintaining ‘Mini-Verde’ bermudagrass and ‘Diamond’ zoysiagrass golf greens at acceptable quality and playability.

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9. Tolerance of creeping bentgrass and annual bluegrass control with Amicarbazone

Amicarbazone is an herbicide currently being developed for use in fine turf by Arysta Life Sciences. Amicarbazone selectively inhibits acetolactase synthase, an enzyme present in photosystem II of plants. Research trials were initiated to compare application rates and timings for annual bluegrass control in creeping bentgrass putting greens throughout North Carolina and were compared to paclobutrazol. Data suggests amicarbazone may selectively control annual bluegrass in creeping bentgrass putting greens.

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10. Tolerance of Tall Fescue to Sulfentrazone When Applied with Various Fertilizers and Three-Way Herbicides

Tall fescue (Festuca arundinacea Schreb.) is a widely used turfgrass in home lawns throughout the transition zone. It is common practice for lawn care operators to apply combination herbicides tank-mixed with various fertility regimes to reduce site visits. However, research has shown that applications of sulfentrazone tank-mixed with urea can injure tall fescue. Research was conducted to determine the tolerance of ‘Confederate’ tall fescue to sulfentrazone with various fertilizers (46-0-0, 34-0-0, and 20-20-20) applied independently (30-45 minutes after herbicide application) or tank-mixed together.

Results indicated that all combinations of sulfentrazone applied independently or tank-mixed with 46-0-0, 34-0-0, or 20-20-20 injured tall fescue, with injury lasting upwards of two weeks after the application. An additional experiment was conducted to determine the tolerance of ‘Confederate’ tall fescue to sulfentrazone tank-mixed with urea, three-way herbicides, and/or chelated iron. As seen in the previous study, treatments containing sulfentrazone and urea injured tall fescue; however, the addition of chelated iron reduced turfgrass injury.

RESULTS (PDF)

RESULTS (PDF)

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11. Imprelis – A new active ingredient for weed control in cool season turfgrass

DPX-MAT28 2SL is an herbicide being developed for use in cool- and warm-season turf by DuPont. DPX-MAT28 will likely be registered for use in residential and commercial lawns, golf courses, parks, athletic fields and sod production and offers control of many annual and perennial broadleaf weeds. Species controlled include clover and vetch species, Carolina geranium, common chickweed, catsear and common dandelion, and buckhorn and broadleaf plantain, among other species.

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12. Digging deeper: The Science of Soil Insect Pests

In a world that has become conscience of pesticide usage, it is imperative to understand the biology of the targeted pest to achieve the highest level of control with minimum reliance on chemicals. When a product is applied at the appropriate time in the insect’s biology maximum damage can be achieved with minimal product. This strategy can reduce the cost of controlling the insect, both monetarily and environmentally.

For effective pest management strategies to be developed we must have an understanding of the pest’s biology, behavior, and habitat in which it exists. Acquiring this knowledge becomes increasingly more difficult when the pest in question spends the majority of its time underground. It is not feasible to dig up large areas of earth to learn this information, and while there are various methods for observing subterranean pests that provide insight, they do not tell the whole story. Currently novel approaches to monitoring terrestrial and subterranean pest are being developed using new technologies.

Much is already known about mole cricket biology and behavior, but much is still unknown. We have developed a technique using RFID technology to monitor mole cricket movement. A chip is inserted surgically into the cricket. The cricket is released into treated and untreated plots. The movement of the crickets is monitored and the data collected will be used to confirm avoidance by the crickets to treated soils.

Billbugs have become the hot topic of discussion. Although they are not a problem for every one they are a problem if you have them. Traditionally thought to be a pest of zoysia grass we are finding that they do significant damage in bermuda grass as well. Research projects from the past three summers have resulted in a better understanding of the species presence, life cycle, and control tactics. Additional research will provide product efficacy for control and timing, along with new monitoring approaches.

RESULTS (PDF)RESULTS (PDF)

RESULTS (PDF)

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13. Fungicide application strategies for prevention of fairy rings on golf putting greens,

Although preventative fungicide applications are commonly prescribed for other soil borne turf diseases, chemical control of fairy rings has historically centered on curative fungicide use. Several of the DMI fungicides have proved effective for preventive fairy ring control, but the impact of strategies such as application timing, irrigation timing, and tank mixing of wetting agents is unknown. This field day stop will highlight two studies investigating these various application strategies, and present the current recommendations for fairy ring control.

This research is funded by the GCSAA Chapter Cooperative Research Program, Carolinas Golf Course Superintendents Association, Bayer Environmental Science, and the Center for Turfgrass Environmental Research and Education at NC State.

Fairy ring control afforded by Bayleton when applied at a 65°F soil temperature threshold: A. Plot to the right of the yellow line was sprayed with Bayleton at the 2 oz/1,000 sq ft rate; B. Plot to the left of the yellow line was sprayed with Bayleton at the 1 oz/1,000 sq ft rate. Photos were taken in mid June and early July.

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14. Disease update 2009,

Field trials are underway to evaluate fungicides and other management practices for control of important turf diseases like dollar spot, brown patch, anthracnose, Pythium blight, gray leaf spot, and many more. Results of these trials will be summarized and updated management strategies will be presented.

RESULTS (PDF)

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15. Smart irrigation technology: An update,

This study is evaluating several turf irrigation management strategies including those using “Smart” technologies. Two types of soil moisture sensor technologies, one weather-based technology, and a standard irrigation timer are being evaluated for the amount of water they apply and turf quality. Turf quality is being assessed through a visual index, radiation reflectance (NDVI), canopy temperatures, and digital image analysis. In addition, the effect of three watering frequencies on water use and turf health is being compared. This study is ending its third year. Plans for future research include converting half the plots to zoysiagrass and adding another weather-based controller. This research is providing information to turf and landscape irrigation managers and local municipalities in the understanding and implementation of smart irrigation technologies.

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