Pacific Island Ecosystems at Risk (PIER)


Zoysia japonica


RISK ASSESSMENT RESULTS: Low risk, score: 6 (low risk based on second screen)


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.

Research directed by C. Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service

Information on Risk Assessments
Original risk assessment

Zoysia japonica; Korean lawngrass

Answer

1.01

Is the species highly domesticated?

y=-3, n=0

n

1.02

Has the species become naturalized where grown?

y=-1, n=-1

1.03

Does the species have weedy races?

y=-1, n=-1

n

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

1

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

2

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

y

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

n

2.05

Does the species have a history of repeated introductions outside its natural range? y=-2

?=-1, n=0

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

n

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

n

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

n

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

n

4.01

Produces spines, thorns or burrs

y=1, n=0

n

4.02

Allelopathic

y=1, n=0

n

4.03

Parasitic

y=1, n=0

n

4.04

Unpalatable to grazing animals

y=1, n=-1

n

4.05

Toxic to animals

y=1, n=0

n

4.06

Host for recognized pests and pathogens

y=1, n=0

n

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

n

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

n

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

n

4.1

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

y

4.11

Climbing or smothering growth habit

y=1, n=0

n

4.12

Forms dense thickets

y=1, n=0

y

5.01

Aquatic

y=5, n=0

n

5.02

Grass

y=1, n=0

y

5.03

Nitrogen fixing woody plant

y=1, n=0

n

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

6.02

Produces viable seed.

y=1, n=-1

y

6.03

Hybridizes naturally

y=1, n=-1

y

6.04

Self-compatible or apomictic

y=1, n=-1

6.05

Requires specialist pollinators

y=-1, n=0

n

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

y

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

2

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

y

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

n

7.04

Propagules adapted to wind dispersal

y=1, n=-1

7.05

Propagules water dispersed

y=1, n=-1

n

7.06

Propagules bird dispersed

y=1, n=-1

n

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

7.08

Propagules survive passage through the gut

y=1, n=-1

y

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

n

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

y

8.03

Well controlled by herbicides

y=-1, n=1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

y

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

Total score:

6

Supporting data:

Source

Notes

1.01

Murray, J. J.; O'Neill, N. R. (1987) Registration of 'Belair' zoysiagrass. Crop Science, 1987, Vol.27, No.1, p.151

AB: Zoysia japonica cv. Belair, a vegetatively propagated cultivar, originated from F2 polycross progeny of a selection believed to have been introduced from North Korea. Established turf of Belair is medium coarse in texture and less dense than that of Meyer. In field trials in Maryland, Illinois and New Jersey, Belair proved superior to Meyer in rate of spread, drought tolerance, autumn colour retention, early spring growth and resistance to Puccinia zoysiae. Belair is easier to mow than other Z. japonica cultivars and is less prone to thatching. It has performed well at low to moderate fertilizer levels and growth is sufficient to establish turf at soil pH levels of 5.4 to 7.0. Belair is similar to Meyer in its area of adaptation.

1.02

(1)USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?42306 (19 May 2002) (2)http://turfgrass.com/ubb/Forum1/HTML/000083.html (3)Wunderlin, R.P. 1998 Guide to the vascular plants of Florida. University Press of Florida, Gainesville.

(1)"cult. & naturalized elsewhere " [no details given, could find no clear evidence of naturalization/reproduction in nature] (2)'Zoysia is naturalized in the Keys, It looks great and grows well on pure coral rock and fill,You can water a patch that crops up in a barren area and get it to spread across the entire yard. ' (3)occurs rarely on disturbed sites

1.03

no evidence

2.01

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?42306 (19 May 2002)

Distributional range:

Native: Asia-Temperate: China - Anhui, Fujian, Hebei, Heilongjiang, Jiangsu, Jilin, Liaoning, Shandong, Zhejiang; Japan - Hokkaido, Honshu, Kyushu, Shikoku; Korea; Taiwan

2.02

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?42306 (19 May 2002)

Distributional range:

Native: Asia-Temperate: China - Anhui, Fujian, Hebei, Heilongjiang, Jiangsu, Jilin, Liaoning, Shandong, Zhejiang; Japan - Hokkaido, Honshu, Kyushu, Shikoku; Korea; Taiwan

2.03

(1) USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?42306 (19 May 2002)
(2) Hayakawa, Y.; Takahata, S. (1975) Studies on the ecological management of pastures. 3. The ecology and distribution of Zoysia japonica Steud. on the northern limits. Research Bulletin of the Hokkaido National Agricultural Experiment Station, 1975, No.111, pp.125-142, 15 ref.

(1) Distributional range:
Native: Asia-Temperate: China - Anhui, Fujian, Hebei, Heilongjiang, Jiangsu, Jilin, Liaoning, Shandong, Zhejiang; Japan - Hokkaido, Honshu, Kyushu, Shikoku; Korea; Taiwan
(2) AB: In Japan Z. japonica occupies coastal grasslands and pastures on poor soil where competition from Poa pratensis is low. The standing crop yield was low, but resistance to drought and treading and the covering power of the species were high. Many Zoysia pastures have been replaced by introduced species, but it is concluded that Zoysia should be retained on steep pastures and on poor stony soils. The northern limit for the species was 43 deg 15'N.

2.04

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?42306 (19 May 2002)

Distributional range:
Native: Asia-Temperate: China - Anhui, Fujian, Hebei, Heilongjiang, Jiangsu, Jilin, Liaoning, Shandong, Zhejiang; Japan - Hokkaido, Honshu, Kyushu, Shikoku; Korea; Taiwan

2.05

USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Introduced in USA: Alabama; California; Florida; Illinois; Indiana; Kentucky; Louisiana; Maryland; Tennessee; Virginia

3.01

(1)USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?42306 (19 May 2002) (2)http://turfgrass.com/ubb/Forum1/HTML/000083.html

(1)"cult. & naturalized elsewhere " [no details given, could find no clear evidence of naturalization/reproduction in nature] (2)'Zoysia is naturalized in the Keys, It looks great and grows well on pure coral rock and fill,You can water a patch that crops up in a barren area and get it to spread across the entire yard. ' (3)occurs rarely on disturbed sites

3.02

no evidence

3.03

no evidence

3.04

no evidence

3.05

no evidence

4.01

no description of these traits

4.02

no evidence

4.03

no evidence

4.04

Kuroki, M.; Ikeda, H.; Kaseda, Y.; Hoshino, M. (1975) Studies on the Misaki horse. 3. Nutrient composition of main herbs and shrubs, and estimates of their nutrient intake. Bulletin of the Faculty of Agriculture, Miyazaki University, 1975, Vol.22, No.1, pp.93-97, 6 ref.

AB: "Zoysia japonica was the species grazed most during summer and Miscanthus sinensis during winter. "

4.05

no evidence

4.06

no evidence

4.07

no evidence

4.08

USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

fire resistant

4.09

USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Shade Intolerant

4.1

Unruh, B., L.E. Trenholm, and J.L. Cisar (2000) Zoysiagrass in Florida. Fact Sheet ENH11, a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: May 1991. Revised: October 2000. Available at <http://edis.ifas.ufl.edu/BODY_LH011.html#FOOTNOTE_1>

"Zoysiagrasses are adapted to a variety of soils "

4.11

turf grass

4.12

http://www.aces.edu/pubs/anr/anr-1129/anr-1129.htm

Once established, zoysiagrasses provide extremely dense, slow-growing sod that will reduce weed establishment and

competition.

5.01

terrestrial

5.02

turf grass

5.03

turf grass

5.04

turf grass

6.01

Hayashi, I.; Numata, M. (1971) Viable buried seed population in the Miscanthus and Zoysia-type grasslands in Japan. Ecological studies on the buried-seed population in the soil related to plant succession. 6. Japanese Journal of Ecology, 1971, Vol.20, No.6, pp.243-252, 39 ref.

AB: There were 10 times as many buried seeds of Zoysia japonica as of Miscanthus sinensis in the top-soil. The M. sinensis stand is one of the seral stages progressing to forest and maintains a dynamic equilibrium under mowing and burning; the M. sinensis stand was converted to Z. japonica by grazing. Maintenance of the M. sinensis community depends on vegetative regrowth from underground organs while maintenance of the Z. japonica community depends on buried seeds.

6.02

Matsumura, M.; Nakajima, N. (1984) Intraspecific variations in some characters related to seed propagation of Zoysia japonica. (2). Seed germinability of maintained clonal lines derived from different localities. Journal of Japanese Society of Grassland Science, 1984, Vol.30, No.3, pp.216-223, 9 ref.

AB: There were significant differences between 30 local clones, grown under uniform garden conditions, in germination, though on average germination was poor. Response to 4 pretreatments for germination control also differed between the clones. Germination data transformed into relative values and averaged over 4 treatments gave the relative germination degree (RGD) as a general index for the evaluation of germinability. The correlation coefficient of germinability based on the RGD between the untreated and treated seeds was r = 0.77, suggesting that most of the clones have clone-specific germinability under variable conditions. Most clones were classified on the basis of RGD and germination characteristics into germination type C, with moderate germination of untreated seeds and good sensitivity to pretreatment, and only 6 into type D, with good germination of untreated seeds.

6.03

Choi JoonSoo; Ahn ByungJoon; Yang GeunMo (1997) Classification of zoysiagrasses (Zoysia spp.) native to the southwest coastal regions of Korea using RAPDs. Journal of the Korean Society for Horticultural Science, 1997, Vol.38, No.6, pp.789-795, 17 ref.

AB: Some 66 zoysiagrass (Zoysia spp.) ecotypes collected from the southwest coastal regions of Korea and 2 ecotypes of Z. tenuifolia and Z. matrella from the USA were classified using RAPD analysis. Seventeen polymorphic bands were obtained by PCR analysis using 5 random primers. Ecotypes were classified into 4 major groups by cluster analysis and subdivided into 8 groups according to growth characteristics. Group I included Z. macrostachya which was characterized by large seed width (1.4 mm). Group II included Z. sinica and natural hybrids exhibiting Z. sinica characteristics, such as narrow and long seeds. Group II exhibited the highest ratio (5.4) of seed length to seed width among the groups. Group III included Z. japonica and natural hybrids exhibiting Z. japonica characteristics, such as hairy and wide (5.2 mm) leaves. Z. matrella, Z. tenuifolia and their variants exhibiting natural hybrid characteristics were included in Group IV. Distinguishing between Z. sinica and Z. macrostachya was very difficult

6.04

Tanaka, H. (1975) Pollination of some Gramineae. 2. Journal of Japanese Botany, 1975, Vol.50, No.1, pp.25-31, 6 ref.

AB: "In protogynous florets in Alopecurus japonicus, A. aequalis var. amurensis, Zoysia japonica and Pennisetum alopecuroides f. purpurascens the lodicules are lacking or rudimentary. "

6.05

Plants for a Future, The Field, Penpol, Lostwithiel, Cornwall, PL22 0NG, England
Telephone Bodmin (+44 1208) 873554
Website: www.pfaf.org

"The flowers are hermaphrodite (have both male and female organs) and are pollinated by Wind."

6.06

turf grass with stolon

6.07

http://www.aces.edu/pubs/anr/anr-1129/anr-1129.htm

Due to the fact that zoysiagrasses have such a slow growth rate, they require 2 to 3 years to fully cover a lawn if established from vegetative plugs. [estimate given is based on slow growth for a grass]

7.01

lawn clippings

7.02

Unruh, B., L.E. Trenholm, and J.L. Cisar (2000) Zoysiagrass in Florida. Fact Sheet ENH11, a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: May 1991. Revised: October 2000. Available at <http://edis.ifas.ufl.edu/BODY_LH011.html#FOOTNOTE_1>

"This species was introduced into the United States in 1895 and is commonly called Japanese or Korean lawngrass. "

7.03

no evidence

7.04

small, non-descipt seeds. might be carried by wind but more likely gravity.

7.05

no adaptation to water dispersal

7.06

no evidence (low-growing inflorescence0

7.07

no means of attachment

7.08

Ide, Y.; Hayashi, H.; Shimoda, K.; Sakanoue, S. (1999) Effect of dissemination of seeds along with cattle dung on the propagation of Kentucky bluegrass (Poa pratensis L.). 2. Seasonal changes in the recovery and viability of seeds in cattle dung on the pasture and the invasion to the sloping Sasa -type pasture with the seeds embedded in cattle dung. Grassland Science, 1999, Vol.45, No.2, pp.163-169, 12 ref.

AB: The seasonal recovery and viability of seeds of Kentucky bluegrass (Poa pratensis ) in cattle dung were studied in the Alpine Region of Central Japan. Observations were also made of the invasion pattern of Kentucky bluegrass onto the sloping Sasa -type grassland by seeds embedded in cattle dung at Sugadaira in central Japan. The initiation of flowering and seed setting of Kentucky bluegrass occurred in the middle and the end of June, respectively. The first recovery of seeds in cattle dung was observed at the beginning of July, but the germination of the seeds recovered was only 12%. The maximum recovery occurred in the middle of July, when germination reached 56%. Thereafter, seed recovery decreased rapidly, ending by the middle of August. Based on these results, it was concluded that dissemination of seeds along with cattle dung was possible from 4-8 weeks after the initiation of flowering. Vegetation of the experimental paddock at Sugadaira could be broadly divided into Zoysia and Sasa types. Major sp

8.01

(1) Matumura, M.; Nakajima, N.; Kurumado, K. (1990) Genecological studies on Japanese lawn grass (Zoysia japonica Steud.) with special reference to the seed propagation characteristics. (2) Seed productivity. Research Bulletin of the Faculty of Agriculture, Gifu University, 1990, No.55, pp.259-265, 14 ref.
(2) Yeam, D. Y.; Joo, Y. K.; Huh, K. Y. (1987) Effect of fertilizer application on seed production in zoysia grass (Zoysia japonica Steud.) Journal of the Korean Society for Horticultural Science, 1987, Vol.28, No.2, pp.165-172, 24 ref.
(3) Matumura, M.; Nakajima, N. (1982) Intra specific variations in some characters related to seed propagation of Japanese lawn grass. (1). External morphology and fertility of seeds derived from 33 preserved lines collected from 26 localities. Research Bulletin of the Faculty of Agriculture, Gifu University, 1982, No.46, pp.365-373, 19 ref.

(1) AB: Ten clones each of 40 local populations of Zoysia japonica from Japan could be classified into 4 major groups depending on their seed productivity and fertility.
(2) AB: The seed yields from plants treated with N at rates from 0 to 80 g/m2 were more than double those from untreated plants; medium N rates were more effective than higher rates. The numbers of spikes and seeds per spike, and vegetative growth (DW of shoots and roots, numbers of shoots and leaves, and leaf width and length) were positively correlated with N rate. Application of P2O5 and K2O at rates from 0 to 40 g/m2, with or without N, did not increase seed yields but decreased the length of rhizomes and the number of leaves.
(3) AB: In c. 30 collection of Zoysia japonica native to localities at latitude 30-43 deg N and 50-1500 m alt. grown under uniform field conditions, seed shape and 100-seed wt. varied considerably among collections. There was no clear relationship between seed morphology and site of origin. Seed fertility also

8.02

Hayashi, I.; Numata, M. (1971) Viable buried seed population in the Miscanthus and Zoysia-type grasslands in Japan. Ecological studies on the buried-seed population in the soil related to plant succession. 6. Japanese Journal of Ecology, 1971, Vol.20, No.6, pp.243-252, 39 ref.

AB: There were 10 times as many buried seeds of Zoysia japonica as of Miscanthus sinensis in the top-soil. The M. sinensis stand is one of the seral stages progressing to forest and maintains a dynamic equilibrium under mowing and burning; the M. sinensis stand was converted to Z. japonica by grazing. Maintenance of the M. sinensis community depends on vegetative regrowth from underground organs while maintenance of the Z. japonica community depends on buried seeds.

8.03

Christoffoleti, P. J.; Aranda, A. N. (2001) Herbicide selectivity to five species of turfgrasses. FT: Selectividade de herbicidas a cinco tipos de gramas.] Planta Daninha, 2001, Vol.19, No.2, pp.273-278, 6 ref.
(2) Koo SukJin; Ahn SeiChang; Lim JaeSuk; Chae SangHern; Kim JungSoo; Lee JaeHwan; Cho JinHo (1997) Biological activity of the new herbicide LGC-40863 O -[2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoyl]oxime}. Pesticide Science, 1997, Vol.51, No.2, pp.109-114, 7 ref.
(3) Czarnota, M. A.; Bingham, S. W. (1997) Control of yellow and purple nutsedges (Cyperus esculentus and Cyperus rotundus ) in turfgrass with MON-12051. Weed Technology, 1997, Vol.11, No.3, pp.460-465, 19 ref.
(4) Smith, W. F., III (1974) Phytotoxicity and degradation of atrazine in selected zoysiagrass varieties. Dissertation Abstracts International, B, 1974, Vol.34, No.10, p.4774

(1) AB: "Among the tested herbicides, halosulfuron at 112.5 g a.i./ha and 2,4-D at 2010 g a.i./ha were the most selective ones, and the grass species of the genus Zoysia were, in general, the most tolerant to all the herbicides tested."
(2) AB: "Herbicidal characteristics of the experimental compound LGC-40863 (pyribenzoxim) were investigated in greenhouse and field studies during 1995 in Korea Republic. In the greenhouse, LGC-40863 had strong post-emergent activity on weeds, including Echinochloa crus-galli , Alopecurus myosuroides and Polygonum hydropiper , while it was safe for rice, wheat and the turf species Zoysia japonica." (3)AB: Field studies were conducted at Blacksburg and Baskerville, Virginia, from 1993 to 1995 to evaluate the sulfonylurea herbicide MON-12051 (methyl 5--3-chloro-1-methyl-1-H -pyrazole-4-carboxylate) for turfgrass tolerance and control of yellow and purple nutsedges (Cyperus esculentus and C. rotundus , respectively). The availability of herbicides for selective control of the

8.04

a lawn grass, tolerates frequent mowing, cultivation

8.05

http://www.aces.edu/pubs/anr/anr-1129/anr-1129.htm

damaged by the hunting billbug and nematodes


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