ASSESS THE PERFORMANCE AND COMPETITIVE ABILITY OF TURFGRASS CULTIVARS IN BLENDS

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	2130	1060	100%

Progress 07/01/03 to 09/30/07

Outputs
OUTPUTS: Research reports were desiminated in both oral and written formats. Oral research presentations were made at professional meetings, industry sponsored seminars, and state and regional turfgrass conferences and shows. Written reports were published in industry trade magazine journals, web site postings, abstracts and scientific journals. PARTICIPANTS: Pam Sherratt, Turfgrass Extension Specialist, Department of Horticulture and Crop Science, The Ohio State University. Co/PI; David Gardner, Associate Professor, Department of Horticulture and Crop Science, The Ohio State University, Co/PI; Partial grant support was provided by the Ohio Turfgrass Foundation TARGET AUDIENCES: The audience for the research was the turfgrass industry both locally and nationally. Specifically, those companies and professionals involved in sportsturf management including athletic fields and golf courses.

Impacts
Investigations found that intraseeding new creeping bentgrass cultivar into an established cultivar at putting green height were unsuccessful. Regardless of treatments for establishing the new cultivar, the existing stand of creeping bentgrass was too competitive for newly established seedlings. Experimental glyphosate resistant creeping bentgrass cultivars were found to be no more competitive when established into a Kentucky bluegrass turf than non-transformed creeping bentgrass cultivars. The "weediness" of glyphosate resistant creeping bentgrass would be expected to be the same as a traditionally bred cultivar. Newly developed hybrid bluegrasses (Poa arachnifera x Poa pratensis) performed well under similated athletic field wear studies. Overall quality and wear tolerance show potential as athletic field turfs in situation of low to medium maintenance. Hybrid bluegrass could be used in similar situations as Kentucky bluegrass (Poa pratensis)

Publications

No publications reported this period

Progress 01/01/06 to 12/31/06

Outputs
In 2005 five turfgrass species (Fustuca arundinacea, Poa pratensis, Poa arachnifera x Poa pratensis, Lolium perenne , Festololium loliacium) were established in the field to evaluate establishment rate and traffic tolerance that would be expected on commonly used sports turfs. Lolium perenne and Festulolium cultivars germinated in 3 to 5 days and established the quickest. The turfgrasses that established the quickest from the May 21 seeding date had the least weed pressure. Festololium is a recently new turfgrass species that germinated quickly and provided an initial dense turf. However, under wear simulation Festololium performed poorly and appears unsuitable for sports turf use. The cultivar Thermal Blue from the new species Poa arachnifera x Poa pratensis demonstrated good wear tolerance showing potential promise as a sports turf species in relatively low maintenance situations. The Festuca arundinacea cultivars established in this study were reported to produce rhizomes. In our study several of the cultivars exhibited rhizome growth but significantly less than Poa pratensis. In the second year of this study (2006), similar results were found. The Festolium loliacium performed poorly under simulated traffic. Thermal Blue performed similar to Poa pratensis. At this time Thermal Blue would be a suitable turfgrass to mix with other sports field turfs like Poa pratensis.

Impacts
The performance of Thermal Blue under sports turf field conditions has been excellent. This turfgrass species has the potential to be added to the list of recommended turfgrasses

Publications

No publications reported this period

Progress 01/01/05 to 12/31/05

Outputs
Five turfgrass species (Fustuca arundinacea, Poa pratensis, Poa arachnifera x Poa pratensis, Lolium perenne , Festololium loliacium) were established in the field to evaluate establishment rate and traffic tolerance that would be expected on commonly used sports turfs. Lolium perenne and Festulolium cultivars germinated in 3 to 5 days and established the quickest. The turfgrasses that established the quickest from the May 21 seeding date had the least weed pressure. Festololium is a relatively new turfgrass species that germinated quickly and provided an initial dense turf. However, under wear simulation Festololium performed poorly and appears unsuitable for sports turf use. The cultivar Thermal Blue from the new species Poa arachnifera x Poa pratensis demonstrated good wear tolerance showing potential promise as a sports turf species in relatively low maintenance situations. The Festuca arundinacea cultivars established in this study were reported to produce rhizomes. In our study several of the cultivars exhibited rhizome growth but significantly less than Poa pratensis. Further evaluation of these relatively new turfgrass species and cultivars will be continued through 2006.

Impacts
Evaluation of alternative new turfgrass species may help reduce energy inputs and help provide quality sports fields with little maintenance. From this study improvements in high school sports fields maybe achieved with using alternative species.

Publications

No publications reported this period

Progress 01/01/04 to 12/31/04

Outputs
Annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis stolonifera) coexist on golf greens as a dynamic ecosystem in the temperate regions of the United States. In a two-year field study, the competitive ability of different populations of annual bluegrass was investigated both in and out of their native environment. The two different environments were golf greens located at The Country Club in Cleveland, Ohio (41 deg 24 min north latitude and 81 deg 51 min west longitude) and Camargo Club in Cincinnati, Ohio (39 deg 06 min north latitude and 84 deg 25 min west longitude). Seventy-two plugs of annual bluegrass were removed from golf greens and inserted into polyvinyl chloride pipe measuring 10.2 cm in diameter and 15 cm in length. Thirty-six plugs then were reestablished into one of three greens at the same golf course, and the remaining 36 plugs were transported to the opposite location and also established into one of three preselected greens. At each location the native population of annual bluegrass outperformed the imported population. Differences at the beginning of the study are attributed to an additional acclimation period required by the exported population following transportation to the opposite location. From our study, annual bluegrass performance was similar across populations.

Impacts
Annual bluegrass is widespread throughout Ohio. Knowing its characteristics and performance will help us develop management programs that could be applicable on a regional basis.

Publications

MCGUAN, M.J., T.K. DANNEBERGER, AND D.S. GARDNER. 2004. Regional differences in the relative competitive ability of annual bluegrass (Poa annua L.) HortScience: (in press)

Progress 01/01/03 to 12/31/03

Outputs
Genetically transformed cultivars of creeping bentgrass (Agrostis stolonifera) that are resistant to glyphosate have been developed. The potential exists for the transformed creeping bentgrass plants to escape and establish into non-target turf areas where the plants may act as weeds. Prior to commercial release, we desired to determine if the transformed plants behaved similarly to creeping bentgrass cultivars in a stand of Kentucky bluegrass. Vegetative plugs of both transformed and non-transformed creeping bentgrass cultivars were established into a mature stand of "Victa", "Coventry", and "Abbey" Kentucky bluegrass. The turf was maintained at 5 cm, mowed regularly and irrigated when needed. The competitive ability of the creeping bentgrass was measured through lateral spread once a month. Currently, after 3 years of study, we have found no difference in the competitive ability of the transformed creeping bentgrass compared to the non-transformed.

Impacts
Knowing the competitive ability of genetically modified creeping bentgrass will help answer the question, "If transformed creeping bentgrass plants were to escape into a situation where it was considered a weed, would a transformed creeping bentgrass be more competitive?"

Publications

GARDNER, D.S., DANNEBERGER, T.K., NELSON, E., MEYER, W., AND PLUMLEY, K. 2003. Relative fitness of glyphosate-resistant creeping bentgrass lines in Kentucky bluegrass. Hortscience 38(3):455-459.

Progress 01/01/02 to 12/31/02

Outputs
Annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris) coexist on golf greens as a dynamic ecosystem in the temperate regions of the United States. In a two-year study, the competitive ability of different populations of annual bluegrass was investigated both in and out of their native environment. In 2000 at both The Country Club in Cleveland, OH and Camargo Club in Cincinnati, OH 72 plugs of annual bluegrass were removed from golf greens and inserted into a piece of polyvinyl chloride pipe. Thirty-six plugs were then re-established into one of three greens at the same golf course, and the remaining 36 were transported to the opposite location and also established into one of three preselected greens. Competitive ability was measured as the rate of increase or decrease in average diameter of each plug. Results showed significant (P<0.05) differences in the location x population interaction throughout the first three measurement periods and then again in the last two measurement periods. Differences at the beginning of the study are attributed to an additional acclimation period that was required by the exported population following transportation to the opposite location. At the end differences in the interaction were again prevalent and it is believed that these differences will continue.

Impacts
Knowing the competitive ability of annual bluegrass in different climactic regions will help develop management programs to control this plant. If annual bluegrass performs similar in foreign environments as well as in native environments encompassing control recommendations can be made.

Publications

McGuan, Michal J. 2002. Regional differences in the relative competitive ability of annual bluegrass "M.S. Thesis" The Ohio State University, Columbus, OH.

Progress 01/01/01 to 12/31/01

Outputs
41. Progress Report Intraseeding a new creeping bentgrass (Agrostis stolonifera) into an existing stand of creeping bentgrass is a common practice in the golf course management industry. The concept is to convert an old stand of creeping bentgrass overtime through the gradual introduction of the new cultivar with minimal disturbance. A study was initiated to evaluate intraseeding procedures on establishing of new creeping bentgrass cultivars. Our treatments consisted of various combinations of coring, vertical mowing, plant growth regulators, and topdressing. The study was conducted over a two-year period. Using random amplified polymorphic DNA (RAPD) procedures we found no successful means of introducing a new creeping bentgrass cultivar into an existing stand short of total renovation. It appears from our study that newly germinated seedlings in an already established turf are unable to compete against the existing plants.

Impacts
Our intraseeding study will save considerable time and expense for golf course superintendents who have over the years tried to convert their golf greens from an older type cultivar to a new one. We hope our results will convince golf course superintendents that to make a conversion to a new cultivar total renovation is desired.

Publications

GOLEMBIEWSKI, R.C., DANNEBERGER, T.K. DANNEBERGER, AND SWEENEY, P.M. 2001. Lack of dollar spot (Sclerotinia homoeocarpa F.T. Bennett) influence on changing the cultivar composition of a stand of creeping bentgrass. International Turfgrass Society Research Journal 9:665-668.
SWEENEY, P.M.,DANNEBERGER, T.K., WANG, D. AND MCBRIDE, M. 2001. Root weight, nonstructural carbohydrate content, and shoot density of high-density creeping bentgrass cultivars. HortScience 36(2):368-370.
KENDRICK, D.L. 2000. Determining the competitive success of an intraseeded creeping bentgrass culitvar in an established putting green "M.S. Thesis" The Ohio State University, Columbus, OH.

Progress 01/01/00 to 12/31/00

Outputs
Restriction amplification fragment length polymorphic (RAFLP) markers show promise as genetic markers in diploid outcrossing perennial ryegrass. After screening 88 primers that produced distinct fragments with five restriction enzymes, 64 restriction loci were identified. Sixteen of these appeared to be polymorphic for the restriction locus and were regarded as potential RAFLP markers. The progeny of crosses of heterozygous perennial ryegrass plants were evaluated to determine whether the proposed RAFLP markers identified in the parental plants segregated according to Mendelian genetics as predicted for codominant markers. Although 16 tentative RAFLP markers were identified, only one segregated as expected for a single locus with two alleles. Our results suggest that useful RAFLP markers will be difficult to find for outcrossing turfgrass species.

Impacts
The identification of markers in perennial ryegrass would be an invaluable resource for further genetic studies in perennial ryegrass.

Publications

Bell, G.E. and T.K. Danneberger. 1999. Reducing populations of annual bluegrass and roughstalk bluegrass in creeping bentgrass fairways: A nutritional approach. Weed Technology 13:829-834.

Progress 01/01/99 to 12/31/99

Outputs
Creeping bentgrass (Agrostis stolonifera) turf exposed to shade during morning hours may decline more readily than similar turf exposed to afternoon shade. Studies were initiated to compare the quality and physiological responses to creeping bentgrass turf exposed to morning shade with turf exposed to afternoon shade and evaluated responses of the same species exposed to varying shade densities during the same period. Semipermanent shade structures were placed on a creeping bentgrass range maintained at a 6.4-mm height. Each structure was covered with either 80 to 100% shade cloth and replicated three times. Canopy temperatures, in comparison with air temperature, was 7% greater in morning shade than in afternoon shade, but the relationship between canopy temperatures in full sun and shade did not change during the day.

Impacts
Shade is detrimental to turfgrass growth. It has been approximated that 25% the turfgrass grown is exposed to low light conditions in some form. Understanding the effects of shade on turfgrass growth will allow us to develop appropriate management programs. Our results so far have shown no difference between morning and afternoon shade with regard to radiant energy affects.

Publications

Bell, G.E. and Danneberger, T.K. 1999. Temporal shade on creeping bentgrass turf. Crop Sci. 39:1142-1146.
Bell, G.E. and Danneberger, T.K. 1999. Managing creeping bentgrass in shade. Golf Course Management 67(10):56-60.
Sweeney, P.M. and Danneberger, T.K. 1999. Introducing a new creeping bentgrass cultivar through interseeding: Does it work? Ohio Turfgrass Newsletter 61(1):14-15.

Progress 01/01/98 to 12/31/98

Outputs
Electrophoresis is commonly used in agricultural sciences and industries to evaluate protein constituents for plant cultivar or species identification. Visual analysis of polymorphic bands is effective, but comparison of electrophoretic banding patterns containing common bands of differing optical densities is difficult and subjective. The purpose of this study was to test computer-assisted image analysis for quantitative evaluation of electrophoretic bands. Seed protein was extracted from mixtures and blends of turfgrass species and cultivars, separated on isoelectric focusing gels, and stained for esterase activity. Banding patterns were scanned and computer-assisted evaluation of band densities performed. Repetitive scans of varying band densities revealed that significant variation occurred among gels, scans, and among gel positions. However, when multiple bands from the same sources were averaged across a single gel and evaluated from a single scan, computer-assisted image analysis proved accurate for discriminating bands with minor density variation.

Impacts
(N/A)

Publications

BELL, G.E., MCDONALD, JR., M.B., DANNEBERGER, T.K., and ST. MARTIN, S.K. 1998. Sources of variation in computer imaging of electrophoretic gels. Crop Science 38:523-526.
GOLEMBIEWSKI, R.C. and DANNEBERGER, T.K. 1998. Dollar spot severity as influenced by trinexapac-ethyl, creeping bentgrass cultivar, and nitrogen fertility.#2 Agronomy Journal 90466-470.
SWEENEY, P.M. and DANNEBERGER, T.K. 1998. Introducing a new creeping bentgrass cultivar through interseeding: Does it work? USGA Green Section Record 36(5):19-20.

Progress 01/01/97 to 12/31/97

Outputs
Dollar spot (Sclerotinia homoeocarpa) is a widely distributed and destructive pathogen of turfgrass in the United States. A 2-yr field study was conducted to determine the influence of a plant growth regulator, creeping bentgrass cultivars, and nitrogen fertility on dollar spot severity. Crenshaw creeping bentgrass was seeded alone or in a 1:1 blend by weight with Penncross creeping bentgrass. Plots were fertilized at 0, 24.4 or 48.7 kg N ha-1 per application. Half of each plot received trinexapac-ethyl treatments initiated in May with subsequent applications made at 30 d intervals for a total of five applications per year. Initially, the blend reduced the rate of dollar spot development compared to Crenshaw alone by 55 percent. However, neither the blend nor Crenshaw provided sufficient dollar spot suppression throughout the study. In August of 1996 the amount of dollar spot present in the blend and Crenshaw was 45 percent and 45 percent, respectively. In 1997, no difference in the amount of dollar spot was detected between the blend and Crenshaw. The amount of dollar spot was 17 percent less in Trinexapac-ethyl treated plots as compared to the control. Nitrogen rate had the greatest effect on the amount of dollar. The 24.4 and 48.7 kg N treatment had 58 percent and 86% less dollar spot than the control, respectively. In summary, both trinexapac-ethyl and nitrogen fertility significantly reduced dollar spot severity over the past year.

Impacts
(N/A)

Publications

GOLEMBIEWSKI, R.C., DANNEBERGER, T.K., and SWEENEY. P.M. 1997. Identification of creeping bentgrass cultivars using randomly amplified polymorphic DNA (RAPD) markers. Crop Science 37:212-214.
BELL, G.E., DANNEBERGER, T.K., and MCDONALD, M.B. 1997. Chemical inhibition of cool-season turfgrass germination. International Turfgrass Society Research Journal 8:411-417.
DEISBURG, K.L., CHRISTIANS, N.E., MOORE, R., BRANHAM, B.E., DANNEBERGER, T.K., RICARD, Z.J., VOIGHT, T., MINNER, D.D., and NEUMAN, R. 1997. Species for low-input sustainable turf in the U.S. Upper Midwest. Agronomy Journal 89:690-694.

Progress 01/01/96 to 12/30/96

Outputs
Blending, planting two or more cultivars of the same species together, has become a common turfgrass management practice. The objective of this study was to evaluate population changes in a 50/50 blend of Crenshaw and Penncross creeping bentgrass (Agrostis stoloniferous) cultivars. Plots were seeded September 1994. Disease levels (dollar spot) of 0, 25 and 90% were allowed to occur on the blend. Randomly amplified polymorphic DNA (RAPD)was used to determine the population composition of Crenshaw and Penncross after initial establishment and at the end of the growing season (October). Results for the first year show that after initial establishment (2 months) that the composition of the blend was 44% and 56%, respectively for Crenshaw and Penncross. At year's end, a significant change in proportion of Crenshaw to Penncross occurred with Crenshaw levels lower than Penncross. However, the change was not due to disease. We speculate the the change was due to the more aggressive nature of Penncross compared to Crenshaw in our region.

Impacts
(N/A)

Publications

SWEENEY, P.M. and DANNEBERGER, T.K. 1996. Restriction digestion of arbitrary amplification fragments of Poa annua L. Crop Sci 36:1301-1303.
SWEENEY, R.M., GOLEMBIEWSKI, R. C., and DANNEBERGER, T.K. 1996. RAPD analysis of dry turfgrass seed. HortScience 31:400-401.
GOLEMBIEWSKI, R.C., DANNEBERGER, T. K., and SWEENEY, P.M. 1996. Identification ofcreeping bentgrass cultivars using randomly amplified polymorphic DNA (RAPD) markers. Crop Sci. (In press).
GOLEMBIEWSKI, R.C., DANNEBERGER, T. K., and SWEENEY, P.M. 1997. RAPD analysis of creeping bentgrass (Agrostis stolonifera) seed and leaf tissue. Int. Turfgrass Soc. Res. J.(in press)
BELL, G. E., DANNEBERGER, T. K., and MCDONALD, M.B. 1997. Chemical inhibition of cool-season turfgrass germination. Int. Turfgrass Soc. Res. J. (in press).

Progress 01/01/95 to 12/30/95

Outputs
Random amplified polymorphic DNA (RAPD) markers from leaf tissue extractions areeffective for discrimination of turfgrass varieties. The usefulness of RAPD markers for turfgrass variety identification can be enhanced by use of seed rather than leaf tissue for DNA extractions. In order to determine whether DNA extracted from turfgrass seed was suitable for amplification, DNA was extracted from bulk samples and individual seeds of bermudagrass, chewings fescue, Poa annua, Poa supina, creeping bentgrass, Kentucky bluegrass, perennial ryegrass, and tall fescue. All samples were successfully amplified using an arbirtrary primer. Amplification intensity varied among species. With an almost infinite number of arbitrary primers available, it is likely that suitable primers can be found to amplify DNA from most turfgrass species. Amplification of turfgrass seed DNA, whether bulk or individual seed, is possible and should prove more useful than amplification of leaf tissue DNA for discrimination of turfgrass varieties.

Impacts
(N/A)

Publications

SWEENEY, P.M. and DANNEBERGER, T.K. 1995. RAPD characterization of Poa annua L. populations. Crop Sci. 35:1676-1680.
BELL, G.E., MCDONALD, JR.,M.B. and DANNEBERGER, T.K. 1995. Evaluation of Kentucky bluegrass blends using isoelectric focusing and computer imaging. Seed Sci. Tech. 23 (in-press).
BELL, G.E., MCDONALD, JR., M.B. and DANNEBERGER, T.K. 1995. Electrophoretic evaluation of esterase isozymes from turfgrass seed blends and mixtures. J. Turf. Manag. 1(3):(in press).

Progress 01/01/94 to 12/30/94

Outputs
Although identical populations of Poa annua L. may colonize golf course greens and fairways, different management practices may cause genetic shifts in adjacent populations. Cores were collected from greens and fairways of three golf holes. RAPD markers were used to evaluate differences between the two environments. Eighty-six primers were screened to evaluate differences between bulk samples of greens and fairways. Twelve primers produced 12 RAPD markers. Five of these were used to evaluate 54 individual plant samples from the two environments. Statistical evaluation of the frequency of four RAPD markers indicated significant differences (P=0.0l) between the green and fairway populations. These differences indicate possible gene flow between adjacent populations of Poa annua which may need to be considered in developing strategies to control Poa annua.

Impacts
(N/A)

Publications

BELL, G.E., MCDONALD, M.B. AND DANNEBERGER, T.K. 1994. Computer imaging for evaluation of eletrophoretic gels. HortScience "in-press".
DANNEBERGER, T.K. ET AL. 1994. Susceptibility of Poa annua L. to anthracnose as influenced by water stress. J. Turfgrass Mgmt. "in-press".
DANNEBERGER, T.K., AND HUDSON, R.A. 1994. Characterization of localized dry spots on creeping bentgrass turf in the United States. Science & Golf 2:477-482.
SWEENEY, P.M. AND DANNEBERGER, T.K. 1994. Random amplified polymorphic DNA (RAPD) between two perennial ryegrass varieties: bulk sample versus individual seedlings. HortScience 29:624-626.
DIMASCIO, J.A., SWEENEY, P.M., DANNEBERGER, T.K. AND KAMALAY, J.C. 1994. Analysis of heat shock response in perennial ryegrass using maize heat shock protein clones. Crop Sci. 34:798-804.
DANNEBERGER, T.K. 1994. Integrating classroom instruction with turfgrass field experience through a golf course project. J. Nat. Res. & Life Sci. Educ. 23:56-58.
BELL, G.E., MCDONALD, M.B., AND DANNEBERGER, T.K. 1994. Evaluation of Kentucky bluegrass blends using isoelectric focusing and computer imaging. Int'l Seed Test. Assoc. and Int'l Soc. for Hort. Sci. Wageningen, Netherland.

Progress 01/01/93 to 12/30/93

Outputs
The usefulness of random amplified polymorphic DNA (RAPD) in characterizing heterogeneous turfgrass populations has not been determined. Amplification products of two perennial ryegrass (Lolium perenne L.) synthetic cultivars were compared. Two out of ten arbitrary primers produced 3 RAPDs that distinguished bulk samples of 30 seedlings. Additional fragments were apparent when DNA from individual seedlings were amplified. Amplification products from bulk samples were not the sum of amplification products of individual seedlings and did not reflect all the diversity within or between the cultivars. To accurately evaluate the genotypic composition of a synthetic cultivar a number of individuals need to be screened.

Impacts
(N/A)

Publications

SWEENEY, P.M. AND DANNEBERGER, T.K. 1993. Random amplified polymorphic DNA (RAPD) between two perennial ryegrass varieties: bulk sample versus individual seedlings. HortScience: "in-press".
DANNEBERGER, T.K., ET.AL. P.E. 1993. Susceptibility of Poa annua L. to anthracnose as influenced by water stress. J. Turfgrass Management: "In press".
DIMASCIO, J.A., ET.AL. 1993. Analysis of heat shock response ln perennial ryegrass using maize heat shock protein clones. Crop Sci.: "in-press".
HAPP, K., MCDONALD, M.B., AND DANNEBERGER, T.K. 1993. Application of vigor testing in perennial ryegrass seeds. Seed Sci. and Tech. 21: "In press".
SWEENEY, P.M., ET.AL. 1993. Fidelity of amplification fragment length polymorphisms (ALFPs) within multiple extractions from single seedlings of hard, chewings, and red fescue. Int. Turfgrass Soc. Res. J. 7:768-774.
VARGAS, J.M., JR., AND DANNEBERGER, T.K. 1993. Effects of temperature, leaf wetness duration, and inoculum concentration on infection of annual bluegrass by Colletotrichum graminicola. Int. Turfgrass Soc. Res. J. 7:324-328.
GERON, C.A., ET.AL. 1993. The effects of establishment methods and fertilization practices on nitrate leaching from turfgrasses. J. Environ. Qual. 22:119-125.
SWEENEY, P.M., AND DANNEBERGER, T.K. 1993. Random amplification of polymorphic DNA (RAPD) characterization of Poa annua L. populations in greens and fairways. Abstr. Amer. Soc. Agron. P 164.

Progress 01/01/92 to 12/30/92

Outputs
Seed vigor testing is an important component of seed analysis. Commonly used vigor tests were evaluated to determine their ability to assess seed quality in perennial ryegrass seed lots. Standard germination results showed no significant difference in germinability among the three seed lots. Germination percentages from the cold test were lower than those from standard germination, but no significant differences (P<0.05) were observed. However, significant differences in shoot height of seedlings following both the germination and cold test were found. Single seed and bulk conductivity tests showed significant differences among the seed lots with the single seed conductivity test producing greater differences in germination percentage and shoot height among the seed lots.

Impacts
(N/A)

Publications

DANNEBERGER, T.K., MCDONALD, M.B., JR., GERON, C.A., AND KUMARI, P. 1992. Rate of germination and seedling growth of perennial ryegrass seed following osmoconditioning. HortScience 27:28-30.
GERON, C.A., DANNEBERGER, T.K., TRAINA, S.J., LOGAN, T.J., AND STREET, J.R. 1992. The effects of establishment methods and fertilization practices on nitrate leaching from turfgrass. J. Environ. Quality. In press.

Progress 04/01/91 to 12/30/91

Outputs
This study evaluates the effects of seed osmoconditioning on germination and seedling growth of perennial ryegrass (Lolium perenne L.). Seeds were osmoconditioned in polyethylene glycol 8000 with water potentials ranging from 0 to -1.4 MPa for 48 hours. Osmoconditioning for this crop at -1.1 MPa resulted in a 35% germination increase after 48 hours under optimum (15/25C) germination conditions. This promotive effect was observed until 104 hours for percentage germination and root growth and 118 hours for shoot growth. Rate of seed germination and seedling root growth of osmoconditioned seeds also was enhanced when seeds were placed under suboptimum germination temperatures of 5, 10, and 15C. These results suggest that while osmoconditioning-enhanced initial germination rate and seedling root growth under laboratory conditions, it did not do so under prolonged favorable conditions. However, the promotive effects of osmoconditioning were more beneficial when seeds were exposed to less favorable germination conditions.

Impacts
(N/A)

Publications

DANNEBERGER, T.K., MCDONALD, M.B., GERON, C.A. and KIMARI, P. 1992. Rate of germination and seedling growth of perennial ryegrass seed following osmoconditioning. Hort. Science 26: (In press).