Kentucky bluegrass

Abstract

A variety of Kentucky bluegrass which exhibits good resistance to common lawn grass diseases including leaf spot, leaf rust, stripe smut and powdery mildew, has an attractive, rich, dark green color and a turf-type growth habit.

Description

SUMMARY OF THE VARIETY

This invention relates to a new and distinct variety of Poa pratensis which has been designated P-101 Kentucky bluegrass.

The variety was originated by crossing an upatentedselection identified in our breeding records as Bellevue with Anheuser Dwarf (U.S. Plant Pat. No. 3,135), Bellevue being the seed parent and Anheuser Dwarf the pollen parent. As a result of this breeding, I have produced and asexually propagated by rhizomes, tillers and disseminules, a variety which is distinct from each of its parents and from all other varieties of which I am aware.

Asexual reproduction of P-101 by propagules (tillers and rhizomes) and by disseminules (modified caryopses produced by agamospermy) has consistently produced progeny plants indistinguishable from the mother plant.

The novel characteristics of the P-101 Kentucky bluegrass variety reside particularly in its attractive, rich, dark green color which can be maintained throughout the entire growing season, moderately wide leaf blades, turf-type growth habit, good resistance to common turf diseases including leaf spot, leaf rust, stripe smut and powdery mildew and its ability to produce a high quality turf. Specifically, P-101 exhibits the following unique combination of characteristics:

1. Good resistance to the leaf spot and crown rot disease caused by the fungus, Helminthosporium vagans;

2. Good resistance to the stripe smut disease caused by the fungus, Ustilago striiformis;

3. Good resistance to powdery mildew caused by the fungus, Erysiphe graminis;

4. Good resistance to the leaf rust disease caused by the fungus, Puccinia poae-nemoralis.

5. An attractive, rich, dark green color which can be maintained throughout the entire growing season;

6. Good rhizome and tiller development under turf maintenance producing a turf of moderate density and good horizontal spreading ability.

7. A leafy turf-type growth habit tolerant of moderately close mowing;

8. Moderately wide leaf blades;

9. Large spikelets; and

10. Good turf performance, as evidenced by consistently high performance scores in tests in New Jersey and Ohio.

In comparison with its seed parent, Bellevue, the new variety has wider leaves, larger spikelets, a darker green color, maintains a more leafy turf during late spring and has better resistance to stripe smut and powdery mildew.

In comparison with its pollen parent, Anheuser Dwarf, the new variety has taller, more upright culms and better early spring color.

In comparison with its sister selection, P-72 (U.S. Plant Pat. No. 3,782), the new variety is taller, has fewer panicles and produces a more leafy turf in late spring.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a photograph of a P-101 Kentucky bluegrass plant after completion of anthesis;

FIG. 2 shows a typical mature P-101 panicle; and

FIG. 3. shows an established plot of P-101 Kentucky bluegrass maintained under turf conditions in which the front half has been cut at 3/4 inches, the back half at 13/4 inches.

DETAILED DESCRIPTION OF THE VARIETY

P-101 Kentucky bluegrass (Poa pratensis L.) is perennial with creeping rhizomes forming a moderately dense turf. Culms are quite erect with only a slight bend at lower nodes, tufted averaging 74 cm tall when undisturbed by clipping. Leaves are dark green, averaging 4.2 mm wide; the blades are hairless on both sides, initially folded but then opening out with a boat-shaped apex. Ligules are membranous and covered with fine hairs, edge of collar is fringed in fine hairs. The flag leaf averages 45 mm in length. Panicles at time of anthesis are green, lightly tinged with purple, slightly nodded at the tip, pyrimidal and open averaging 99 mm long. Lower branches are mostly perpendicular to the main panicle axis, lowest cluster of branches usually in a whorl of 3 to 4 (average 3.5). Spikelets are ovate, compressed, 4.7 to 6.8 mm long (average 5.7), usually 4 to 5-flowered (average 4.4), breaking up at maturity beneath each lemna. Glumes persistent, pointed, unequal, rough on the keels; lower mostly 1 -nerved, ovate averaging 3.1 mm long, upper 3-nerved, ovate to elliptic averaging 3.5 mm long. Lemmas overlapping, 5-nerved, oblong or ovate in side view, pointed tip, hair on the keel and nerves to the middle, long fine crinkled hair at the base and on the lower margin. Paleas about as long as the lemmas with 2 rough keels. Grain tightly enclosed in the lemma and palea.

Since environmental conditions such as soil and climate influence morphological characters to some degree, the morphological characteristics will vary somewhat. Morphological characteristics of P-101 are compared with other Kentucky bluegrass varieties in Table 1.

Table 1. __________________________________________________________________________ Morphological comparison of P-101 and other bluegrass varieties at Adelphia, New Jersey Number of Number branches Leaf Flag of Panicle at Plant Plant Blade leaf panicles erect lowest Panicle height diameter width length per panicle or panicle length Variety cm cm mm mm plant color.sup.1 nodding.sup.2 node mm __________________________________________________________________________ P-101 74 25 4.2 45 78 1.5 2.0 3.5 99 P-72 66 26 4.0 47 199 1.5 1.5 3.9 102 Delta 73 17 2.6 67 196 2.0 1.0 4.8 100 Geary 80 24 2.9 80 177 3.0 3.0 4.0 134 Newport 79 30 4.8 77 246 2.5 2.0 4.3 105 Palouse 79 24 3.0 93 151 3.0 3.5 4.4 92 Anheuser Dwarf 67 30 5.1 51 109 3.0 2.5 3.4 96 Belturf 70 35 3.0 58 201 2.0 2.0 4.0 104 Fylking (U.S. Pat. No. 2887) 60 34 4.0 68 164 3.5 5.0 4.9 118 Merion 70 24 4.3 69 280 2.0 1.5 3.5 102 Pennstar 59 34 3.7 66 132 3.5 4.0 4.5 106 __________________________________________________________________________ .sup.1 Scale: 0 = green; 5 = purple .sup.2 Scale: 1 = erect; 5 = nodding

The new variety has exhibited consistently high turf performance ratings at New Brunswick, N. J. and Marysville, Ohio. Overall turf performance ratings for P-101 and other bluegrasses are presented in Tables 2 and 3.

Table 2. ______________________________________ Turf performance ratings of P-101 and other bluegrass varieties at New Brunswick, New Jersey ______________________________________ Turf Performance Score 9 = best Variety 1966 1967 1968 1969 1970 Ave. ______________________________________ P-101 7.8 8.5 8.4 7.9 7.0 7.9a* Anheuser Dwarf 7.6 7.3 7.5 6.9 7.6 7.4a Fylking 6.9 6.8 8.0 7.6 7.2 7.3a Pennstar 6.9 6.8 7.9 7.1 7.2 7.2a Belturf 6.2 5.9 7.4 7.0 6.2 6.5b Bellevue 6.4 6.7 6.9 5.9 5.7 6.3b Merion 6.3 6.1 6.8 4.9 4.1 5.6c Delta 4.5 4.2 5.2 4.9 4.5 4.7d ______________________________________ *Values within a column followed by the same letter do not differ at the five percent probability level.

Table 3. ______________________________________ Relative comparison of P-101 and other bluegrass varieties growing under natural shade at Marysville, Ohio. ______________________________________ Turf quality score 9 = best Variety May 16 July 1 September 30 Ave. ______________________________________ P-101 7.7 7.7 7.8 7.7 P-72 7.9 6.6 6.9 7.1 Merion 6.2 6.2 5.7 6.0 Fylking 4.7 4.7 4.1 4.5 Pennstar 4.8 4.1 3.0 3.8 Park 3.0 4.5 3.3 3.6 ______________________________________

The new variety has a dark green color which can be maintained throughout the growing season. Color rating comparisons of P-101 and other bluegrasses grown at Accokeek, Md., are presented in Table 4.

Table 4. ______________________________________ Color rating comparisons of P-101 and other bluegrass varieties grown at Accokeek, Maryland. Color rating (10 = darkest green) Feb. Apr. May June July Sept. Nov. Variety 14 1 22 15 22 5 22 Ave. ______________________________________ P-101 9.0 8.0 9.0 9.0 8.0 8.5 8.0 8.5 P-72 8.0 8.0 8.0 8.0 9.0 8.0 9.9 8.4 Sydsport 6.5 6.0 6.0 7.5 8.0 8.0 6.8 7.0 Windsor 7.0 6.0 5.5 7.0 7.0 8.3 6.5 6.8 Nu Dwarf 2.0 6.0 6.0 7.0 7.0 8.0 6.5 6.1 Common Kentucky 4.0 7.0 5.0 6.0 7.0 7.0 6.0 6.0 ______________________________________

The new variety is moderately aggressive with good horizontal spreading ability as shown by measurements presented in Table 5.

Table 5. ______________________________________ Aggressiveness of various bluegrass varieties as measured by their ability to spread under conditions of close mowing and competition from other bluegrasses at New Brunswick, New Jersey. ______________________________________ Amount of encroachment into adjacent bluegrass varie- Variety ties (inches) ______________________________________ P-101 +10.0* Belturf + 8.0 a Bellevue + 3.0 b Pennstar + 2.5 b Fylking + 2.5 b Anheuser Dwarf + 2.0 b Merion - 1.5 c Windsor - 1.5 c Delta - 3.0 c ______________________________________ *Values within a column followed by the same letter do not differ at the five percent probability level.

Comparisons of P-101 and other bluegrasses for resistance to leaf spot and crown rot caused by the fungus Helmintosporium vagans, stripe smut caused by the fungus Ustilago striiformis, powdery mildew caused by the fungus Erysiphe gramins and leaf rust caused by the fungus Puccinia poae-nemoralis are presented in Tables 6, 7, 8, 9, 10 and 11.

Table 6. ______________________________________ Relative comparison of leaf spot and crown rot disease incidence of P-101 and other bluegrasses at New Brunswick, New Jersey. ______________________________________ percent disease Variety damage ______________________________________ P-101 2 a* Anheuser Dwarf 2 a Merion 5 b Fylking 6 b Pennstar 6 b Bellevue 10 b Belturf 20 c Delta 70 d ______________________________________ *Values within a column followed by the same letter do not differ at the five percent probability level.

Table 7. ______________________________________ Relative comparison of leaf spot disease incidence on P-101 and other bluegrass varieties under natural shade at Marysville, Ohio. ______________________________________ Percent leafspot May July September Variety 16 1 30 Ave. ______________________________________ P-101 20 17 8 15 P-72 20 23 9 17 Merion 33 23 15 24 Fylking 38 37 25 33 Pennstar 34 39 40 38 Park 59 44 26 43 ______________________________________

Table 8. ______________________________________ Relative comparison of stripe smut disease incidence of P-101 and other bluegrasses at New Brunswick, N.J. ______________________________________ Stripe smut infected tillers Variety per square foot of turf ______________________________________ Anheuser Dwarf 0 a* Pennstar 0 a Fylking 0 a P-101 2 a Bellevue 11 b Delta 11 b Merion 228 c ______________________________________ *Values within a column followed by the same letter do not differ at the five percent probability level.

Table 9. ______________________________________ Reaction of Kentucky bluegrass varieties to powdery mildew disease under greenhouse conditions at New Brunswick, New Jersey. ______________________________________ Mildew rating Variety 9 = most disease ______________________________________ A-20 0.0 a* P-101 0.7 b Newport 0.8 b A-34 1.8 c Sodco 2.0 c Fylking 3.9 d Pennstar 4.2 d Belturf 4.3 d Merion 6.9 e ______________________________________ *Values followed by the same letter do not differ significantly at the five percent probability level.

TABLE 10. ______________________________________ Relative comparison of powdery mildew disease incidence on P-101 and other bluegrass varieties under natural shade at Marysville, Ohio. ______________________________________ Variety Percent mildew ______________________________________ P-101 2.7 A-34 6.7 P-72 7.3 Nugget 28.3 Common Kentucky 70.0 Pennstar 80.0 Windsor 86.7 Merion 93.3 ______________________________________

Table 11. ______________________________________ Relative comparison of leaf rust disease level for P-101 and other bluegrass varieties at Adelphia, New Jersey. Variety Rust disease rating* ______________________________________ P-101 0.8 a** Pennstar 1.5 b Fylking 1.5 b Prato 2.0 b Newport 3.5 c Merion 3.5 c Vantage 7.5 d ______________________________________ *Rating Scale: 0 = no rust; 9 = disease most severe **Values followed by the same letter do not differ significantly at the five percent probability level.

The new variety is medium late in maturity as indicated by relative comparison of flowering dates presented in Table 12.

Table 12. ______________________________________ Date of initiation of anthesis of Kentucky bluegrass varieties at Adelphia, New Jersey. Variety Date flowers first open ______________________________________ Kenblue* May 18 to May 24 Delta May 20 a** Nugget May 23 b Newport May 25 c Fylking May 26 cd Pennstar May 26 cd Galaxy May 27 de Majestic May 27 de Bonnieblue May 27 de P-101 May 27 de Anheuser Dwarf May 28 ef Merion May 29 fg Adelphi May 30 g Glade May 30 g Brunswick June 2 h ______________________________________ *Kenblue is a mixture of different bluegrass types. **Dates followed by the same letter do not differ statistically at the five percent probability level.

Claims

1. A new and distinct variety of Kentucky bluegrass plant, substantially as shown and described, characterized by good resistance to many important lawn grass diseases, good turf performance, an attractive dark green color, good rhizome and tiller development and moderately wide leaves.