<i>Zoysia </i>grass plant named ‘NARUO1920’

Abstract

NARUO1920 is a new plant of perennial Zoysia grass plant which is distinguishable from other Zoysia plants know to the Inventor by having a very short leaf length, fine leaves, and high creeping ability.

Claims

1. A new and distinct variety of Zoysia grass plant named NARUO1920 as illustrated and described herein particularly characterized by a unique combination of morphological features.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) This application contains at least one drawing executed in color.

(2) FIGS. 1A-1C. Spike stems of NARUO1920 and standard cultivars Meyer and Emerald.

(3) FIGS. 2A-2C. Stolons of NARUO1920 and standard cultivars Meyer and Emerald.

(4) FIGS. 3A-3C. Turf of NARUO1920 and standard cultivars Meyer and Emerald.

(5) FIGS. 4A-4B. Green Index (NDVI) on the turf of the test lines in Winter (February in Japan).

(6) FIG. 4A compares the greenness of the experimental plots from May 2022 through May 2023 according to the Green Index (NDVI).

(7) FIG. 4B shows the increased greenness of the NARUO1920 plot compared to the plots of TM9, Meyer, and Emerald plants.

(8) FIGS. 5A and 5B. Initial growth and covered rate in cultivars.

(9) FIG. 5A shows initial growth in June, July and August for NARUO1920, TM9, Meyer, and Emerald plants.

(10) FIG. 5B, panels 1, 2, 3 and 4, respectively, show coverage of experimental plots on June 2021, October 2021, May 2022, and May 2023.

(11) FIG. 6A compares leaf length (mm) of NARUO1920 to varieties TM9, Meyer and Emerald.

(12) FIG. 6B compares stem length (mm) of NARUO1920 to varieties TM9, Meyer and Emerald.

(13) FIG. 6C compares numbers of ears in Fall (Japan) of NARUO1920 to varieties TM9, Meyer and Emerald.

(14) FIG. 6D compares stolon density (cm) of NARUO1920 to varieties TM9, Meyer and Emerald.

DETAILED BOTANICAL DESCRIPTION OF THE VARIETY

(15) NARUO1920 has very fine leaves and several shoots compared to common Zoysia grass. NARUO1920 had the lowest values of above-ground traits (leaf length and budding stem length) compared to standard cultivars, while it had the highest density of creeping stems. This indicates that NARUO1920 is a compact plant with excellent creeping stem growth. Height: 3.2 cm for NARUO1920, 5.8 cm for TM9, 9.6 cm for Meyer, and 4.8 cm for Emerald.

(16) Spread (defined as the length of stolon per unit area): 344 cm.sup.2 for NARUO1920, 288 cm.sup.2 for TM9, 125 cm.sup.2 for Meyer and 175 cm.sup.2 for Emerald. Spread measured per 100 square centimeters.

(17) Stolon Length of leaf sheath are, respectively, 6.9 mm/NARUO1920, 6.7 mm/TM9, 12.0 mm/Meyer, and 17.5 mm/Emerald.

(18) Density of hair on leaf sheath are, respectively, Sparse/NARUO1920, Sparse/TM9, Sparse/Meyer, and Sparse/Emerald.

(19) Internode lengths are respectively, 12.3 mm/NARUO1920, 11.0 mm/TM9, 18.6 mm/Meyer, and 21.1 mm/Emerald.

(20) Width of internodes are respectively, 0.9 mm/NARUO1920, 1.1 mm/TM9, 1.5 mm/Meyer, and 1.1 mm/Emerald.

(21) Stolon colors are respectively, 60B/NARUO1920, 60A/TM9, 60A/Meyer, and 60A/Emerald; wherein the color codes are given by The R.H.S. Color Chart

(22) FIGS. 1A-1C show the number of ears in the initial stage of each test lines. The number of ears produced was higher than that of standard varieties Meyer and Emerald, but the length of the stems produced was very short, FIGS. 1A-1C, FIGS. 2A-2C show the initial growth and cover of each tested lines.

(23) Although the above-ground portion of NARUO1920 is small, the growth of the filling stems is vigorous. The initial growth and cover speed of NARUO1920 are similar to standard varieties, although the above-ground portion was smaller. This is due to the high shoot density. This can be attributed to the large number of stolon densities as shown by FIGS. 3A, 3B and 3C.

(24) Normalized Difference Vegetation Index (NDVI) was measured over time in the densely planted plots of the test cultivars and the trend of turfgrass color was compared.

(25) The results showed that NARUO1920 exhibited a similar color trend to the standard varieties, but the color of NARUO1920 was most deep in February, the coldest month of the year in Japan. This indicates that NARUO1920 has higher color retention performance in winter than the other varieties.

(26) Meyer is a variety of Zoysia (Zoysia japonica). Since Meyer is a Zoysia japonica, it is generally the most dormant (withering in winter) variety. The results of this study also showed that Meyer had the lowest NDVI value and the lowest color retention.

(27) Emerald is not Zoysia japonica, but color retention was low in winter conditions compared to the standard variety.

(28) Compared to the standard varieties NARUO1920 had very good color retention. Furthermore, the maintenance of greenness of NARUO1920 was visually confirmed as shown in FIG. 4B.

(29) Description of other phenotypes of NARUO1920. Growth characteristics of this plant are very strong creeping and very low erect stem length compared to Meyer and Emerald. The stem is slightly thicker than Emerald, approximately 1.0 mm to 1.5 mm in diameter. The creeping stems are reddish in color and the internodes are approximately 14.9 mm long. The reddish stolon color (Value/Variety) is described by The Royal Horticultural Society (R.H.S.) Color Chart is 60B for NARUO1920, 60A for TM9, 60A for Meyer, and 60A for Emerald.

(30) The length of the emerged ear is very short, approximately 8.5 mm, compared to the control variety. The spikelet length is approximately 2.4 mm and spikelet width is approximately 0.9 mm. The number of spikelets per ear is 14.

(31) Spring vigor is good and fall vigor is moderate compared to the comparative test varieties. Tolerance to summer blight is on par with Meyer and Emerald, and slightly improved for wintering ability. The leaves are rolled in a bud shoot. The leaf width is very fine, around 1.3 mm, and the leaf length is around 12.6 mm.

(32) The leaf color in NARUO1920 is a deeper green than the control variety Emerald and slightly lighter green than Meyer. The leaf blade is flat, with a round bottom, and gradually tapers to an acute point. Mature leaf blades have some trichomes on the front side and few on the underside. The leaf sheath is hairless.

(33) The typical height of NARUO1920 is 3.2 cm; that of TM9 is 5.8 cm; that of Meyer is 9.6 cm and that of Emerald is 4.8 cm.

(34) The typical spread per 100 cm.sup.2 of NARUO1920 is 344 cm.sup.2; that of TM9 is 288 cm.sup.2; that of Meyer is 125 cm.sup.4 and that of Emerald is 175 cm.sup.2. Spread value is defined as the length of the stolon per unit area.

(35) The typical culm length of NARUO1920 is 3.1 cm; that of TM9 is 4.4 cm; that of Meyer is 7.0 cm that of Emerald is 4.8 cm.

(36) The typical culm width of NARUO1920 is 1.0 mm; that of TM9 is 1.5 mm; that of Meyer is 2.5 mm that of Emerald is 2.2 mm.

(37) The typical culm color of NARUO1920 is 140B; that of TM9 is 60A; that of Meyer is 60A that of Emerald is 60A based on The R.H.S. Color Chart.

(38) The flag leaf width of NARUO1920 is 0.43 mm; that of TM9 is 0.8 mm; that of Meyer is 0.8 mm that of Emerald is 0.7 mm.

(39) The typical inflorescence length of NARUO1920 is 8.5 mm; that of TM9 is 26 mm; that of Meyer is 34 mm that of Emerald is 30 mm.

(40) The typical inflorescence width of NARUO1920 is 0.59 mm; that of TM9 is 1.0 mm; that of Meyer is 1.5 mm that of Emerald is 1.0 mm.

(41) The typical color of spikelets (matured) of NARUO1920 is 158B; that of TM9 is 158D; that of Meyer is 158A that of Emerald is 158B.

(42) The typical length of spikelets of NARUO1920 is 2.4 mm; that of TM9 is 2.6 mm; that of Meyer is 3.2 mm that of Emerald is 2.9 mm.

(43) The number of spikelets of NARUO1920 is 14; that of TM9 is 22; that of Meyer is 30, and that of Emerald is 19 mm.

(44) The flowering period of NARUO1920 comprises October 18; that of TM9 is April 22; that of Meyer comprises March 6 that of Emerald comprises March 23 as measured at Kawanishi, Hyogo, Japan.

Other Descriptive Values

(45) Leaf blade length. The typical leaf blade length of NARUO1920 is 12.6 mm; that of TM9 is 37.5 mm; that of Meyer is 95.0 mm, and that of Emerald is 56.5 mm.

(46) Leaf blade width. The typical leaf blade width of NARUO1920 is 1.1 mm; that of TM9 is 1.8 mm; that of Meyer is 3.7 mm, and that of Emerald is 1.8 mm.

(47) Leaf blade intensity of green color. The typical leaf blade intensity of green color of NARUO1920 is 140B; that of TM9 is 142C; that of Meyer is 141C, and that of Emerald is 142C.

(48) Leaf blade margin. The leaf blade margin of NARUO1920 is smooth; that of TM9 is smooth, that of Meyer is smooth, and that of Emerald is smooth.

(49) The leaf blade density of hairs of NARUO1920 is very sparse (about 1 hair/leaf); that of TM9 is very sparse, that of Meyer is sparse (1 hair/leaf) and that of Emerald is sparse.

(50) As described above a NARUO1920 plant may be asexually reproduced by cutting it into 2-3 stems in April at Kawanishi, Hyogo, Japan and transplanting them one by one into a polyethylene pot (60 mm) filled with culture soil (bed soil) and grown for about one month.

(51) FIGS. 6A-6D summarize the comparison of leaf length, ear emergence stem length, number of ears, and stolon density, which are characteristic of NARUO1920. NARUO1920 had much lower values of above-ground traits (leaf length and ear emergence stem length) compared to the control and standard varieties, while the stolon density was the highest, therefore, it was found to be a small plant with excellent stolon growth. The results are consistent with the results in 2019. The number of ears was extremely high, but since the golf course is mowed frequently and ears are cut regularly, the number of ears is not considered to be a problem. These results were obtained from a variety registration test which compared NARUO1920 to TM9, Emerald and Meyer plants. In the nursery at the university, each cultivar was cut into 2-3 stems in April 2021 and transplanted one by one into a polyethylene pot (60 mm) filled with culture soil (bed soil) and grown for about one month. The method of cultivation and research was conducted in accordance with the Criteria and Characteristics Table (Zoysia Wild) on the registration website on: the world wide web <hinshu2.maff.go.jp/info/sinsakijun/kijun/1670.pdf>. Additional traits were assessed using the 25 parameters listed in Table 1 which follows.

(52) TABLE-US-00001 TABLE 1 Phenotype and characteristics of NARUO1920 Plant characteristics State Value Plant habit prostrate Stem size large 1.3 mm Stem length very short 14.9 mm Stolon density very long 344 cm Leaf length very short 12.6 mm Leaf width narrow 1.3 mm Leaf Color medium Ear length very short 8.5 mm Ear color medium Spike let length a little short 2.4 mm Spike let width medium 0.9 mm Number of spikelet per ear few 14 Attachment of husk semi-husked Vigor of early stage a little good Spring vigor a little poor Fall vigor medium Head emergence a little early Oct 24 Heading in spring and/or Fall only Fall Number of ear very many Regrowth vigor poor Greening time a little late Coloring time medium Wintering ability a little good Tolerance to summer depression good