'CAVALIER'

ZOYSIAGRASS

'CAVALIER'

ZOYSIAGRASS

Developed by

Texas A&M University

in cooperation with the

United States Golf Association

1996

Petition to Release

PLANT MATERIALS RELEASE PROPOSAL SUMMARY FORM

Date 9 April 1996

1. CROP: Zoysiagrass Type of Release: Varietal

2. Proposed name or identification: CAVALIER

3. Designation or name in development stages: DALZ8507

4. Primary features or advantages: Cavalier is a Z. matrella which is vegetatively propagated and genetically stable and uniform. Chromosome number is 2n = 40. Cavalier is distinguished from other zoysiagrass by it's fine texture, long, narrow leaf, with low rhizome, but high density stolon production. It has good to excellent salt tolerance, and good shade tolerance. Cavalier is resistant to the fall armyworm and the tropical sod webworm. Cavalier is intermediate in its growth and recovery rate. Cavalier has good - excellent winter hardiness and will persist in regions north to Kansas, Missouri and Southern Illinois as well as the Southern states. Cavalier rated number one in the NTEP trials over 3 yrs at 24 locations ranging from California - Georgia and north to Nebraska and Colorado. Cavalier will find its primary utility in home lawns, golf course fairways and tee boxes and in parks, sports fields and other recreational areas. Cavalier has been identified by several golf course architects as the future grass of choice for golf course fairways in the cool season-warm season transition zone.

5. Plant Variety Protection - suggested action: Certification required. Will recognize Foundation, Registered and Certified classes of sod. Cavalier will be submitted for Plant Patent as this is a vegetatively propagated cultivar.

6. Planting Stock -- amount available and date: Approximately 1,100 m² of breeder class sod and 7,000 m² of foundation class sod are available for immediate harvest and distribution. The breeder and foundation class sod fields are presently under the USDA fire ant compliance program. All planting stock is presently grown at Texas A&M Research and Extension Center - Dallas, TX.

7. Provisions to maintain breeder seed: A breeder field will be maintained by the Texas Agricultural Experiment Station - Dallas, TX.

8. Proposed seed stock distribution: Planting stock from either the breeder fields or Foundation class stock should be made available directly to a licensee for further propagation and maintenance of foundation class sod. In the case of OUT-OF-TEXAS license, the Registered class of sod will be used for further propagation. This variety is expected to have a broad market potential throughout the southern- and Midwestern - to mid-Atlantic states as it has adaptability to golf course fairways, and tee boxes as well as for home lawns and other fine general turf areas. This grass will require production across the area of adaptability and therefore needs to be licensed in such a way as to maintain quality of product, yet maximize its exposure at a reasonable cost to the potential consumer. This variety should be handled as a proprietary product with a National or series of Regional licenses with sub-licensing rights to maximize the appeal for production and marketing.

Submitted by:

Breeder and Scientists- Unit Head
M. C. Engelke - Randy Upshaw

In cooperation with:

Drs. J. A. Reinert , P. F. Colbaugh, Richard White, B. A. Ruemmele, K. B. Marcum and Ms S. J. Morton

CAVALIER ZOYSIAGRASS

M. C. Engelke, J. A. Reinert, P. F. Colbaugh, R. H. White,
B. A. Ruemmele K. Marcum, and S. J. Morton.

Zoysiagrass (Zoysia spp.) is native to the pacific rim countries with climatic extension of latitudes to 50^o. The genera has approximately 10 species recorded in the literature, however only seven of the different species have been collected and studied over the past 50 years, with only three species having commercial significance for turf clture. The primary species of interest are Z. japonica, Z. matrella, and Z. tenuifolia. The species biological adaptation ranges across environmental requiems similar to buffalograss, having excellent tolerance to temperature extremes and tolerance to low moisture conditions. Generally speaking, the coarser textured species ( Z. japonica) have excellent cold hardiness, whereas the finer textured species (Z. tenuifolia) generally lack winter hardiness. The genera is genetically stable with 2n = 40 chromosomes. Zoysia spp. in general have low self fertility, and will intercross among the species. Speciation is primarily attributed to geographic distribution and floral niching. Zoysiagrasses are noted for excellent salt tolerance, tolerance to temperature extremes, and low fertility and moisture requirements. At the onset of the Texas Turfgrass breeding program there were essentially three cultivars of zoysiagrass available to the commercial market, namely 'Meyer', 'Emerald' and 'Midwest'. The primary market area was in the Midwestern regions including Kansas, Missouri and Maryland. Major concerns with the use of zoysia were high establishment costs and availability, as the cultivars were relatively slow to establish, and sod harvest cycles ranged from 15 -30 months. The objectives of the breeding program with Texas A&M as sponsored by the United States Golf Association were to develop cultivars which would fit the environmental niche of reduced water, nutrient and pesticide usage while simultaneous developing varieties which were more economical to produce.

DALZ8507 zoysiagrass proposed name 'CAVALIER' is a fine-textured, long-leaf, vegetatively propagated Zoysia matrella noted specifically for uniformity in appearance and distinct summer presentation. It is genetically stable, basically self-infertile and vegetatively propagated through weak rhizome and strong stolon growth. Cavalier has good shade tolerance, salt tolerance and reasonably good recuperative ability under sports play. Cavalier was developed and submitted for release by the Texas Agricultural Experiment Station in 1996. Its harvest cycle will be approximately 12 months in environments similar to north Texas where it has been grown and harvested over the past 3 years. Cavalier will be suitable for use on sports fields, golf course fairways, and tee boxes, and home lawns. Finer textured varieties such as Cavalier often lack winter-hardiness to survive in the mid-western states. As a Z. matrella, however, Cavalier has demonstrated excellent winter hardiness through evaluation with regional and national trials, and is quite suitable for use as golf course fairways, tees and more specifically home lawns throughout the mid-west to mid-Atlantic states and throughout the south. The production cycle is on a par with Meyer, however its water use, disease and insect resistance and general turf quality is highly superior to Meyer.

Cavalier ranked number 1 in the National Trials over a 3 year period. Cavalier appears similar in appearance to Tifway Bermudagrass, however the variety has improved performance for winter hardiness and survivability under reduced management conditions. Cavalier fulfils all of the criteria set forth in the project sponsored by the USGA breeding program initiated in 1984. Considerable genetic variability does exist among the zoysiagrasses and extensive testing and evaluation is essential to determine agronomic strengths and areas of adaptation. Cavalier has undergone this rigorous testing and presents an excellent new cultivar over a wide area of adaptation.

ORIGIN AND BREEDING HISTORY:

Cavalier is a vegetatively propagated accession of zoysiagrass which was collected from the office grounds of the local county government near Ooneshima, on the southern island (Kyushu) of Japan in 1982. It was a distinct grass growing in a small monoculture among a conglomeration of grasses resembling a native stand of segregating zoysiagrasses which were being maintained as a lawn. This individual plant appeared finer textured, dense, weed free and uniform in appearance in contrast to the general area. The accession was introduced through APHIS and ARS in 1982 and entered in to the germplasm evaluation program in 1983. The turf was tested as TAES 1999 in replicated nurseries with approximately 700 plant accessions from Japan, Korea, Taiwan and the Philippines which had all been collected beginning in 1982. It was singled out in 1985 along with several other plants in various studies and designated as Cavalier. Once designated with the DALZ nomenclature, the accession was entered into more intense evaluation.

PERFORMANCE AND ADAPTATION:

Cavalier has been evaluated in field, greenhouse and laboratory studies in conjunction with the United States Golf Association Zoysiagrass Improvement Program (USGA-ZIP) since 1983 and was included in the 1991 National Turfgrass Evaluation Program (NTEP) along with 24 additional zoysiagrass varieties and cultivars. The NTEP trials were established at 23 distinct environments (locations) in 16 states (Table 1a) (Morris 1993, 1994). The various agronomic performance characters measured are summarized in Table 1b. The planned observations were identified by a committee of scientist familiar with the species and with the targeted utility. Observations were made monthly or seasonally for each of the characters listed at all locations.

Of the 24 varieties in the NTEP trials, 11 varieties were identified as Z. matrella and 13 were identified as Z. japonica (Table 2). In general the Z. matrella species is characterized as fine textured with either short or long leaf length. In contrast, the wider leaf Z. japonica's have a range from a short stubby leaf, to a longer broader leaf type. Cavalier is a long-narrow leaf type (Texture class = 3). Turf quality ratings ranged from 4.1 - 6.1 averaged over 3 yrs and the 23 locations of the NTEP trials. Overall, Cavalier tied for 1st out of 24 for turf quality (NTEP RANK - Table 2) with an average quality reading = 6.1, on a 1-9 scale, where 9 = ideal. When compared only with the 11 Z. matrella's, Cavalier ranked 1st in overall turf performance (Table 2- TPI by species). Quality ratings of the Z. matrella's ranged from 4.1 to 6.1. Recognition must be given to the diversity of climates in which the NTEP zoysiagrass trials were conducted. It is therefore recommended that attention be given to each of the regions and or unique environments of the trials to determine the "local" adaptability of the variety or cultivar under test.

Cavalier ranked 1st in quality and turf performance across all locations for a period of 3 years. However, closer examination of the performance of Cavalier at individual test sites indicates Cavalier ranked 1st only in Urbana, Il, Riverside, CA and Florida in 1992(Table 3). It ranked 16th under full sun at Texas A&M Dallas, and 10th under heavy shade. In 1993 (Table 4) Cavalier ranked either 1st or 2nd in Alabama, Arkansas, Arizona, California, and Georgia but overall it ranked 1st among the 24 entries.

Other important agronomic characteristics include:

WATER USE REQUIREMENTS: Zoysiagrasses differ considerably in their morphological appearance which is often confusing to the practicianer, however the species classification appears to transcend the textural classes designated by other researchers. Species classification of many of the zoysiagrasses is under question. White et al. (1993) grouped the grasses into four textural classes including (1) short narrow, (2) short wide, (3) long narrow, and (4) long wide leaf types. Z. matrella as a group, are generally considered to have rather narrow leaf blades and would include plants of the 1 and 3 Class, whereas Z. japonica as a group, normally have broader leafs and would include Classes 2 and 4. For the sake of grouping the grasses according to "leaf width", only two classes are used in Table 2 which recognizes individual varieties according to species, the finer or narrower leaf types are recognized as Z .matrella's , and the coarser or wider leaf types are designated as Z. japonica's. White et al. (1993) emphasized that leaf width was the dominate feature controlling water needs. The wide leaf types generally required less water than the narrow leaf types regardless of the length, yet considerable genetic variability among the various entries suggest that improvements can be made to lower the water requirements for all types of zoysia plants.

Cavalier is a textural class =3 with long slender leaves and would be considered an intermediate water user according to data collected from the Linear Gradient Irrigation System (Table 5). Cavalier maintains a dense ground cover (Table 6) and ranked closely behind El Toro and Crowne (mean of three irrigation regimes). Without supplemental irrigation, Cavalier ranked a close third behind El Toro and Palisades. Note the superior competition of Cavalier under drought stress Fig 1. as compared to other unmarked entries.

SHADE TOLERANCE: Light, water and nutrition are key components of the environment required for plant growth and development. With adequate water and nutrition, light becomes the limiting factor. According to Dudeck and Peacock (1992) 20 - 25% of all existing turfs is maintained under some degree of shade from buildings, shrubs, or trees.

Zoysiagrass, a "C4" species, generally demonstrates fair to good tolerance to low light conditions. However, low light tolerance appears to be under genetic control and restricted to only a few genetic lines. A study was conducted under live oak (Querus viriginianus Mill.) shade with incoming radiation measured at approximately 10% of full sun light. This study was undertaken to identify the relative low-light tolerance of the 24 varieties and/or cultivars of the 1991 NTEP trials. Assessment of plant performance was based on density, texture, color, percent green cover, and percent turf cover over a 3 year period. The 46 observations (Table 7a) were taken over a period of 4 years are summarized (Table 7b) to show the relative shade tolerance of each grass in the study (Morton et al. 1991, 1994a, 1994b, Morton and Engelke, 1994). Meyer, the commercial standard is generally classified as having reasonable shade tolerance. By comparison, Cavalier ranked 10th (72% cover) among the 26 entries included in this study while Meyer (32% cover) ranked 21st.

SALT TOLERANCE: Meyer has been considered the industry standard among zoysiagrasses and is considered to have a low water requirement and excellent salt tolerance. Studies conducted under greenhouse conditions using a salinity ramping procedure. Ramping occurs by gradually increasing the concentration of salts with daily additions of 1575 ppm NaCl to Hoagland's solution for a period of 12 weeks (Marcum et al. 1994). The test included a total of 59 zoysiagrass entries and additional results are provided in the reference. Selected data for the entries in the NTEP trials are included in Table 8. By comparison, Cavalier is considered to have good-excellent tolerance to salt when compared to Diamond (DALZ8502), El Toro and Emerald zoysiagrass (Marcum et al. 1994) and significantly better than Meyer. The good-excellent salt tolerance of Cavalier expands the utility of this grass as greater pressure is continually being placed on turfgrass managers and consumers to use alternate water supplies; supplies which often have compromised water quality. Long term continued use of poor quality water will lead to elevated and often toxic salt levels in the grass root zone. Grasses with a lower water requirement and moderate to high salinity tolerance, as demonstrated by Cavalier, will find an important niche in low maintenance turf culture where marginal quality water resources are used.

COLOR RETENTION: Typical of the finer textured zoysiagrasses, Cavalier (avg. 61.7) has excellent fall color retention and is significantly better than Meyer (avg 11.4), and El Toro (avg. 43.1)(Table 9). Z. matrella's generally will retain more tissue coloration than Z. japonica during the fall and early winter months, and typically they are also more sensitive to winter injury.

PEST RESISTANCE:

INSECT and MITES: Fall armyworm and tropical sod webworm can annually be very damaging to warm season turfgrass in the southern U.S. and particularly in the Southeast. The tawny mole cricket is the number one most damaging insect problem to turfgrass in the southern U.S. The zoysiagrass mite is a relatively new introduction for the Pacific Rim area where it is one of their major pests, and has the potential to cause considerable damage to its host specific grass in the United States.

Meyer expressed resistance to neonate fall armyworm, however, it is susceptible to the later instars. Cavalier appears to have excellent resistance to the fall armyworm regardless of the stage of the insect development (Table 10) (Reinert et al. 1994). Cavalier also demonstrated excellent resistance to neonate larvae and adults of the tropical sod webworm (Table 11)(Reinert and Engelke 1992). Larval weight at 15 days was very small (7.2 mg) compared to same age larvae feeding on Meyer (36.4 mg). Additionally, it took nearly 11 days longer for surviving larvae to emerging as adults on Cavalier than on Meyer. Insect and mite response of Cavalier is summarized in Table 12. Cavalier appears to be resistant to the fall army worm (Reinert et al. 1994), moderately resistant to the tropical sod webworm (Reinert and Engelke 1992), and the tawny molecricket (Braman et al. 1994), but susceptible to the zoysiagrass mite (Reinert et al. 1993.). In contrast, Meyer is susceptible to each of these pests. Multiple insect resistance in Cavalier may play a very important role in the success of zoysia as a turf species.

DISEASE RESISTANCE:

Common diseases of zoysiagrasses include two viral diseases; Zoysia dwarf and Zoysia mosaic found in Japan (Smiley, et al. 1992) and of fungal diseases including Zoysia rust (Puccinia zoysiae), and the yellow patch disease (Rhizoctonia cerealis) that are widely distributed fungal diseases. Susceptibility of Zoysia japonica to Sclerotinia Dollar Spot has also been observed (Smith et al. 1989).

Inoculation studies were conducted with 18 experimental and six commercial zoysiagrasses at TAMU-Dallas to determine their relative susceptibility to Rhizoctonia blight. Field collected zoysiagrass plugs were inoculated in a walk-in growth chamber over a 7-day period. Rhizoctonia blight susceptibility differed significantly among the genotypes in the study (Metz et al, 1993, 1994). Cavalier was classified as resistant to Rhizoctonia. In a second inoculation study, 40 experimental and commercial zoysiagrasses were used to determine relative susceptibility to Pythium blight (Pythium aphanadermatum) which is a common foliar turfgrass pathogen in the southern growing zones. Results of this study indicated Cavalier to be moderately resistant (Colbaugh and Engelke, 1993a, 1995).

Cavalier was not included in studies concerning Sclerotina dollar spot (Table 12). In general however it is believed that zoysiagrasses with fine leaf texture and high leaf density were generally more dollar spot susceptible that turfgrasses with coarser leaves and lower leaf density (Colbaugh and Engelke, 1993b).

Cavalier has multiple pest resistance as summarized in Table 12. The test summarized in these studies was conducted under controlled conditions of the greenhouse, laboratory or field and only allow us to predict actual performance under field conditions. Many of the commercial and experimental zoysiagrasses are resistant to two or more pests and/or diseases which are problematic for turfgrass producers and managers. Information about multiple pest and disease resistance in five DALZ lines and three commercial varieties obtained from studies discussed previously are summarized in Table 12.

AGRONOMIC MERITS OF CAVALIER

• COLD HARDY

• SHADE TOLERANT

• SALT TOLERANT

• INSECT RESISTANCE

  TROPICAL SOD WEB WORM
  FALL ARM WORM
  TAWNY MOLE CRICKET

• DISEASE RESISTANCE

  PYTHIUM BLIGHT
  RHIZOCTONIA BLIGHT

• HIGH VISUAL QUALITY

• FINE LEAF TEXTURE

• SPREADS BY STOLONS

• GOOD GENETIC COLOR

AGRONOMIC LIMITATIONS OF CAVALIER

• REQUIRES SHARP REEL MOWER
• SLOW RATE OF ESTABLISHMENT
• SLOW RATE OF RECOVERY
• VEGETATIVE PROPAGATION REQUIRED
• POTENTIAL TENDENCY TO THATCH
• SUSCEPTIBLE TO ZOYSIAGRASS MITE

Table 1a. Listing of states participating in the 1991 Zoysiagrass National Turfgrass Evaluation Trials.

Table 1b. Listing of parameters evaluated which impacted the quality ratings reflected in Table 1.

Table 2. Quality ratings of the 1991 NTEP ZOYSIAGRASS TRIALS over a 3 yr period at 23 locations in 16 states. Data is presented as the rank in performance assigned by the NTEP for each year, the annual and accumulative (TTL) Turf Performance Index (TPI) calculated on the basis of LSD means separations, and the annual quality (1-9, where 9= best) for each of the 3 yrs. Sorted by TPI rank (3 yr avg).

Z. matrella's Finer Textured hybrid leaf types.

Z. japonica's Coarser textured leaf types.

NTEP Rank - based on mean performance over 24 locations each year. Listed by year, overall rank calculated based on simple mathematics. Ties are averaged.

TPI = Turf performance index, separately calculated based on LSD separations provided by NTEP and accumulated based on mean performance at 24 locations each year. Total TPI simple mathematical accumulation of TPI's from previous years.

^*Quality = mean performance of each grass over all locations each year. Simple means calculation to compute over all mean. ^** Tex = Texture from White et al. 1993

Table 3. Ranking Of Mean Turfgrass Quality Ratings Of Zoysiagrass Cultivars At Twenty-Two Locations In The United States^*

1992 DATA

QUALITY RANKINGS; 1=HIGHEST MEAN: STATE LOCATIONS REPORTING**

* This table contains no statistical values (LSD Values). Therefore it should only be used to determine the general performance of an entry or entries across several locations or regions. To assess statistical difference among entries, refer to the means and LSD values found in Table 1.

** Ranking of mean turfgrass quality is achieved by assigning "1" to the highest mean, "2" to the second highest mean, etc. For each location. For example, if two means are tied for second and third ranks, both are assigned "2.5".

Morris, 1993. National Zoysiagrass Test - 1991. Progress Report 1992. Nat. Turf Eval. Prog. NTEP No. 93-4: 9.

Table 4. Ranking Of Mean Turfgrass Quality Ratings Of Zoysiagrass Cultivars At Twenty-Two Locations In The United States^*

1993 DATA

QUALITY RANKINGS; 1=HIGHEST MEAN: STATE LOCATIONS REPORTING**

* This table contains no statistical values (LSD Values). Therefore it should only be used to determine the general performance of an entry or entries across several locations or regions. To assess statistical difference among entries, refer to the means and LSD values found in Table 1.

** Ranking of mean turfgrass quality is achieved by assigning "1" to the highest mean, "2" to the second highest mean, etc. For each location. For example, if two means are tied for second and third ranks, both are assigned "2.5".

Morris, 1994. National Zoysiagrass Test - 1991. Progress Report 1993. Nat. Turf Eval. Prog. NTEP No. 94-5:11.

Table 5. Supplemental irrigation water requirement for commercial and experimental zoysiagrasses during July 1989 through August 1991 at Dallas, Texas.*

MSD, minimum significant difference for comparison of means within columns based on the Waller-Duncan k-ratio t-test (k=100).

Total annual precipitation

*White, et al. 1993.

Table 6. Percentage zoysiagrass ground cover after 3 years of continuous gradient irrigation application at the Texas Agricultural Experiment Station at Dallas for commercial and experimental zoysiagrasses.

*Irrigation levels of high, intermediate, and none on the linear gradient system are equivalent to 87, 29, and 0% of the total water applied at the line source.

**MSD, Minimum significant difference for comparison of means within columns based on the Waller-Duncan k-ratio t-test where k=100.

White et al. 1993.

Table 7a. Summary of observations for the 1991 NTEP zoysiagrass shade trial at TAES-Dallas.

Table 7b. Accumulative performance index (PI) for 1992-1995, for the 1991 NTEP zoysiagrass trial planted under 90% shade at TAES-Dallas.

^* Seeded entry.

**PI = Performance Index is the frequency of occurrence in the top statistical group or when a variety is not statistically different from the top performing variety. Maximum number of observations = 49.

Table 8*. Average percent shoot salt injury (average of 20 rating dates) on zoysiagrass entries in the 1991 NTEP Trials. (From Marcum et al. 1994 CPR-5244) .

^*Selected data set; complete data set includes 59 varieties and cultivars.

NTEP= National Turfgrass Evaluation Program.

Species identity.

Means followed by the same letter are not significantly different, based on the Waller-Duncan k-ratio t-test (k-ratio=100)

^Seed propagated varieties.

Table 9. Green color retention (% of the turf that is green) during winter 1994-5 for the NTEP zoysiagrass trial planted at TAES-Dallas in August 1993.

^** TPI is the turf performanc index, or the number of times an entry was rated in the top statistical group. Statistical tests were performed on transformed data, but means of untransformed data are listed. Means in the top statistical group are indicated by an 'a

^* Seeded entry.

Table 10. Resistance in zoysiagrass to 4-day old larvae of the fall armyworm; survival, weight, and development time.

¹ Number of surviving 17-day-old larvae.
² Mean larval weight taken after 17 days of feeding.
³ Percent surviving to pupation.
⁴ Mean weight of pupa within 2 days of pupation.
⁵ Mean number of days to pupation from egg hatch.
⁶ Mean survival to adult.
⁷ Mean number of days from egg hatch to adult emergence.
⁸ Means in a column followed by the same letter are not significantly different

by Waller-Duncan k-ratio t test (k = 100) (P = 0.05)

Table 11. Resistance to neonate larvae of the tropical sod webworm in zoysiagrass; survival, weight, and development time.

¹ Number of surviving 15-day-old larvae.
² Mean larval weight taken after 15 days of feeding.
³ Percent surviving to pupation.
⁴ Mean weight of pupa within 2 days of pupation.
⁵ Mean number of days to pupation from egg hatch.
⁶ Mean survival to adult.
⁷ Mean number of days to adult emergence.
⁸ Means in a column followed by the same letter are not significantly different

by Waller-Duncan k-ratio t test (k = 100) (P = 0.05)

Table 12 . Summary of pest and disease resistance in selected zoysiagrasses.