St. Augustine grass

Abstract

A perennial St. Augustine grass having outstanding cold tolerance, along with good resistance to St. Augustine Decline Virus and gray leaf spot.

Description

BACKGROUND

A St. Augustine grass which has been named "Seville" was disclosed in U.S. Plant Pat. No. 4,097, which issued on Sept. 6, 1977.

SUMMARY OF THE VARIETY

This invention relates to a new and distinct perennial St. Augustine grass selected from the progeny of the controlled pollination of Seville with the pollen from a cold tolerant selection obtained from Memphis, Tenn. This yellow anther, white stigma genotype was labeled 6-72-99 and propagated vegetatively by stolons to provide planting stock for studying performance and making comparisons to present commercial varieties.

The excellent cold tolerance, good overall appearance, and good resistance to St. Augustine Decline Virus and gray leaf spot of 6-72-99 along with other information, allow this genotype to be distinguished from other St. Augustine grasses.

BRIEF DESCRIPTION OF THE ILLUSTRATIONS

FIG. 1 is a photograph of 6-72-99 St. Augustine turf;

FIG. 2 shows a single spike of 6-72-99 St. Augustine grass plant depicting yellow anthers and white stigmas protruding from several spikelets.

DETAILED DESCRIPTION OF THE VARIETY

Genotype 6-72-99 has a yellow anther color, a white stigma color, and an unreduced chromosome number of 18. The internodes are shorter and thicker than most commonly grown St. Augustine grass cultivars. Leaf blade length and leaf sheath length are significantly shorter than Floratam, a widely grown cultivar in Florida and Texas. The difference between 6-72-99 and Floratam in leaf blade length is accentuated under low light growing conditions. Floratam is noted for its poor shade performance in contrast to most St. Augustine grasses. The blade width of 6-72-99 is equal to or wider than other St. Augustine grasses. Measurements of the spike and related structures indicate that 6-72-99 has a longer spike, a longer peduncle, and a longer flag leaf sheath than other St. Augustine grasses except for Floratam. The chromosome numbers, anther and stigma color and morphological measurements of 6-72-99 and other St. Augustine grasses are compared in Tables 1, 2, 3 and 4.

TABLE 1______________________________________Chromosome numbers, anther color and stigma color of6-72-99 and other St. Augustine grasses. Chromosome Anther StigmaSelection/Variety Number Color Color______________________________________6-72-99 18 Yellow WhiteBitterblue 27 Yellow PurpleFloratam 27 Yellow PurpleFloratine 27 Yellow PurpleRaleigh 18 Yellow WhiteSeville 18 Yellow PurpleTexas Common 18 Yellow WhiteCalifornia Common 18 Yellow White1081 18 Purple Purple______________________________________ TABLE 2______________________________________Comparative measurements of internode length and thicknessof 6-72-99 and other St. Augustine grasses. Internode Internode Length (cm) Thickness (mm)Selection/Variety Florida.sup.(a) Ohio.sup.(b,c) Ohio.sup.(b)______________________________________6-72-99 4.1 5.7 3.5Bitterblue 3.7 6.9 2.7Floratam 6.3 7.5 3.2Floratine 4.7 5.8 2.7Raleigh 5.8 7.0 3.2Seville 4.5 6.8 2.7Texas Common -- 6.2 3.0California Common -- 4.2 2.41081 3.9 7.3 2.8LSD (.05) 1.00 1.15 .24______________________________________ .sup.(a) Field planting Fort Lauderdale, Florida. Average length of thir to seventh internodes on terminal end of stolon. .sup.(b) Greenhouse planting Marysville, Ohio. Measurements taken on unclipped potted plants. .sup.(c) Length of third internode from terminal end of stolon. TABLE 3______________________________________Comparative Leaf Blade Length, Width and Sheath Length of6-72-99 and other St. Augustine grasses. Blade Length (cm) Blade Sheath Ohio.sup.(b) Width.sup.(c) Length.sup.(c)Selection/ High.sup.(c) Low.sup.(d) (cm) (cm)Variety Texas.sup.(a) Light Light Ohio.sup.(b) Ohio.sup.(b)______________________________________6-72-99 3.0 7.3 16.7 1.8 3.3Bitterblue -- 7.4 17.5 1.5 2.8Floratam 6.6 10.1 27.2 1.7 4.5Floratine -- 8.6 16.3 1.4 3.2Raleigh 3.9 7.8 13.8 1.7 3.7Seville 2.9 6.9 18.4 1.4 2.9Texas Common 2.7 8.1 16.6 1.7 3.6California -- 3.8 11.8 1.2 2.2Common1081 -- 7.8 15.2 1.5 3.2LSD(.05) .77 2.03 3.25 0.17 0.71______________________________________ .sup.(a) Field Planting Cleveland, Texas. .sup.(b) Greenhouse Planting Marysville, Ohio. Measurements taken on unclipped potted plants. .sup.(c) After a period of natural sunlight and a high level supplemental light. .sup.(d) After a lengthy period of very cloudy conditions and no supplemental light. TABLE 4______________________________________Comparative measurements of the inflorescence and relatedstructures of 6-72-99 and other St. Augustine grasses.sup.(a).______________________________________ Spike Peduncle Length Width Length WidthSelection/Variety (mm) (mm) (mm) (mm)______________________________________6-72-99 93 5.3 68 2.1Bitterblue 78 5.6 61 2.2Floratam 96 5.9 83 2.4Floratine 74 5.8 48 2.3Raleigh 72 5.8 62 2.2Seville 71 4.9 50 1.9Texas Common 68 4.9 42 1.91081 78 5.2 60 1.9LSD(.05) 10.0 .64 18.3 0.28______________________________________ Flag Leaf Flag Leaf Sheath Length Width LengthSelection/Variety (mm) (mm) (mm)______________________________________6-72-99 21 6.7 46Bitterblue 22 6.4 44Floratam 35 6.3 46Floratine 27 7.2 39Raleigh 25 7.5 42Seville 15 5.8 38Texas Common 29 7.1 391081 25 6.3 39LSD(.05) 12.4 1.08 6.7______________________________________ .sup.(a) Greenhouse planting Marysville, Ohio.

Field observations of 6-72-99 indicate that it has generally good turf quality characteristics throughout the year. However, it excels during the cooler winter and early spring months in its turf quality and its ability to avoid injury to occasional cold and freezing temperatures. These characteristics of 6-72-99 as compared with other St. Augustine grasses is illustrated in Tables 5, 6 and 7.

TABLE 5______________________________________Comparative turf quality.sup.(a) of 6-72-99 and otherSt. Augustine grasses at various locations in the U.S. Turf Quality Florida Fort California Lauderdale SCFS.sup.(h)Selection/ Expt Expt Expt ExptVariety Apopka.sup.(b) 1.sup.(c) 2.sup.(d) 3.sup.(e) 4.sup.(f) Somas.sup.(g)______________________________________6-72-99 7.4 7.5 5.8 6.1 4.7 4.9Bitterblue 6.2 5.6 5.9 -- -- --Floralawn -- -- 7.1 -- -- --Floratam 5.9 6.5 7.2 -- 3.9 --Floratine 6.2 5.3 6.2 -- -- --Raleigh 6.6 3.0 -- -- 3.6 --Seville 7.8 7.3 6.3 6.7 -- 5.3Texas Common 7.5 -- -- 5.9 4.5 3.6California -- -- -- 6.1 4.6 5.3Common1081 7.2 6.1 5.5 -- -- --______________________________________ .sup.(a) Quality rated 1-10, 10 = best. .sup.(b) Mean over 4 years with a total of 8 evaluations. .sup.(c) Mean of 5 dates of evaluations. .sup.(d) Mean of 15 dates of evaluations. .sup.(e) Mean of 25 dates of evaluations. .sup.(f) Mean of 6 dates of evaluations. .sup.(g) Mean of 2 dates of evaluations. .sup.(h) South Coast Field Station University of California. TABLE 6______________________________________Comparative turf quality.sup.(a) of 6-72-99 and otherSt. Augustine grasses during the winter season orearly spring at various locations in the U.S. Turf Quality Apopka.sup.(b) Cleveland.sup.(c) SCFS.sup.(d)Selection/Variety Florida Texas California______________________________________6-72-99 9.9 6.4 5.4Bitterblue 5.0 -- --Floratam 5.6 6.0 --Floratine 5.8 6.0 --Raleigh 7.7 -- --Seville 7.8 6.2 4.5Texas Common 8.9 6.2 4.2California Common -- -- 4.61081 6.4 4.8 --______________________________________ .sup.(a) Quality rated 1-10, 10 = best. .sup.(b) Mean of 3 dates of evaluations. .sup.(c) Mean of 5 dates of evaluations. .sup.(d) South Coast Field Station University of California Mean of 6 dates of evaluations. TABLE 7______________________________________Comparative cold injury of 6-72-99 and otherSt. Augustine grasses in Apopka, Florida. Cold Injury (%)Selection/Variety Expt. 1 Expt. 2 Mean______________________________________6-72-99 0 0 0Bitterblue 53 38 45Floratam 40 42 41Floratine 48 32 40Raleigh 32 12 22Seville 35 15 25Texas Common 18 7 121081 47 33 40LSD(.05) 20.9 18.5______________________________________

Color of turf is an important component of turf quality. 6-72-99 has a pleasing green color throughout the year. In addition, minimizing loss of green color due to herbicide injury, cold, or other causes is also important in maintaining good quality turf for 6-72-99. Besides green color or loss of green color, St. Augustine grasses have a tendency to have a purple coloring in the stem. 6-72-99 has a low level of purpling in the stems. Minimizing the number of seedheads in turf is also important in maintaining high quality turf. 6-72-99 has a medum level of flowering shoots in turf. This information is illustrated in Tables 8, 9 and 10.

TABLE 8______________________________________Comparative color ratings of 6-72-99 and otherSt. Augustine grasses at various locations in the U.S.______________________________________ Color.sup.(a) FloridaSelection/Variety Apopka.sup.(b) Fort Lauderdale.sup.(c)______________________________________6-72-99 8.9 1.8Bitterblue 7.9 3.0Floratam 8.4 2.9Floratine 7.9 2.9Raleigh 7.1 2.0Seville 8.8 2.0Texas Common 8.0 --California Common -- --1081 8.5 1.3______________________________________ Color.sup.(a) California TexasSelection/Variety Somas.sup.(d) SCFS.sup.(e) Cleveland.sup.(f)______________________________________6-72-99 7.9 7.0 6.8Bitterblue -- -- --Floratam -- -- 6.8Floratine -- -- 6.8Raleigh -- -- --Seville 7.5 8.6 6.7Texas Common 5.9 4.2 6.8California Common 7.7 6.5 --1081 -- -- 5.6______________________________________ .sup.(a) Color rated 1-10, 10 darkest green unless noted otherwise. .sup.(b) Mean of 8 evaluations. .sup.(c) Rated 1-3, 3 = darker green. .sup.(d) Mean of 3 evaluations. .sup.(e) South Coast Field Station .sup.(f) Mean of 5 evaluations. TABLE 9______________________________________Comparative ratings of various attributes of 6-72-99 and otherSt. Augustine grasses which detract from overall appearance.Selection/ Dis- Chlo- SeedVariety Brown.sup.(a) color.sup.(b) rosis.sup.(c) Asulox.sup.(d) Heads.sup.(e)______________________________________6-72-99 3.7 1 20.0 0 400Bitterblue -- -- 14.5 12 200Floralawn -- -- -- -- 120Floratam 6.3 -- 11.0 0 60Floratine -- -- 7.5 2 80Raleigh 8.3 -- 10.0 10 --Seville -- 0 17.5 3 1110Texas Common 5.7 0 17.0 0 --California 4.0 4 -- -- --Common1081 -- -- 14.5 7 650______________________________________ .sup.(a) South Coast Field Station University of California Rated as % brown turf. .sup.(b) South Coast Field Station Rated as % discolored turf. .sup.(c) Apopka, Florida Rated as % chlorotic turf. .sup.(d) Apopka, Florida Rated as % injury. .sup.(e) Fort Lauderdale, Florida Rated as the number of seedheads per square meter. TABLE 10______________________________________Comparative evaluations of purple stem color of6-72-99 and other St. Augustine grasses. Purple Stem Color.sup.(a) FloridaSelection/ Ohio Fort CaliforniaVariety Marysville.sup.(b) Lauderdale Apopka SCFS______________________________________6-72-99 3.5 4.5 5 0.7Bitterblue 8.0 5.3 30 --Floratam 8.3 6.1 33 2.7Floratine 8.0 6.3 10 --Raleigh 6.0 4.0 14 1.7Seville 4.0 4.5 1 --Texas 4.5 -- 9 1.0Common1081 7.5 5.9 52 --LSD(.05) 1.1 0.9______________________________________ .sup.(a) Purple stem color rated 1-10, 10 = stolons are very purple, 1 = stolons are entirely green. For Apopka, visual estimation of the level of stem purpling in percent. .sup.(b) Test planted in the greenhouse.

Tolerance to various diseases and insects is important for maintaining good quality turf with minimum levels of pesticides. 6-72-99 has shown resistance to St. Augustine grass Decline Virus inoculations in the laboratory. In field studies, it has shown a good level of resistance to gray leaf spot (Pyricularia grisea) and dollarspot (Curvularia sp.). Tolerance to insects is an extremely difficult characteristic to measure accurately. For chinchbugs (Blissus sp.) and sod webworm (Crambus sp.), 6-72-99 has shown tolerance levels equal to most other St. Augustine grasses.

TABLE 11______________________________________Comparative disease ratings of 6-72-99 andother St. Augustine grasses. Gray Leaf Spot.sup.(a) Dollarspot.sup.(d)Selection/ Apopka.sup.(b) Fort Lauderdale.sup.(c) Fort LauderdaleVariety Florida Florida Florida______________________________________6-72-99 1.0 4.0 0.0Bitterblue 3.5 6.6 0.2Floratam 3.8 4.0 0.0Floratine 2.6 7.0 0.5Raleigh 0.7 3.6 --Seville 0.8 3.8 0.0Texas Common 2.4 -- --1081 2.2 2.7 0.3______________________________________ .sup.(a) Rated 1-10, 10 = most disease. .sup.(b) Mean of two evaluations. .sup.(c) Mean of two evaluations. .sup.(d) Rating based on number of spots per square meter. TABLE 12______________________________________Comparative ratings of insect tolerance of 6-72-99 andother St. Augustine grasses. Chinchbugs.sup.(a) Sod Webworms.sup.(b)Selection/Variety Florida.sup.(c) California.sup.(d) Florida.sup.(e)______________________________________6-72-99 2.0 0.0 49Bitterblue 5.0 -- 24Floratam 7.0 -- 18Floratine 2.7 -- 24Raleigh 6.3 -- 44Seville 5.7 0.3 39Texas Common 4.7 2.0 --California Common -- 3.0 --______________________________________ .sup.(a) Rated 1-10, 10 = severe damage. .sup.(b) Rated as % damage. .sup.(c) Planted in the greenhouse at Apopka, Florida. .sup.(d) South Coast Field Station, University of California. .sup.(e) Planted in containers at Fort Lauderdale, Florida. Mean of two evaluations.

Claims

1. A St. Augustine grass, substantially as herein illustrated and described.