1992-1993 Overseed Turfgrass Trials

D. M. Kopec, J.J Gilbert


Materials and Methods

A field test was established at the Desert Turfgrass Center to evaluate overseed germplasms under a 1/2 inch mowing height regime on a USGA sand based growing medium. Twenty three entries were included in the test which were composed of perennial ryegrass cultivars, experimental accessions, blends, mixtures with Poa trivialis, straight Poa trivialis and one low growing tall fescue. Annual ryegrass and non-overseeded checks were included as well. Treatments and seed rates are listed in Appendix Table A.

A two year old sand green of 'Tifgreen' bermudagrass was verticut on October 14 in three directions. Overseeding mixtures were seeded in 4x12' plots. All overseed entries are listed in Appendix Table B. All plots were replicated three times in the test. Plots were first mowed on 10/30/92 at 3/8", and double mowed everyday afterwards for two weeks down a mowing height of 11/64", up until May 1 when the height was raised to 12/64" during heat stress. Plots were topdressed with 1/4" of sand at overseeding, followed by a 1/4" application on May 1, and a 1/8" application on June 23. Fertilizer applications were made on nine dates comprised of low rates of water soluble complete fertilizers, totaling 4.8 lbs of nitrogen per 1000 ft2, for both tests.

Results and Discussion

Standard Test: Table 1.
Percent cover for rate of establishment and relative ability to provide full cover was significant among the overseed treatments on each of the seven dates it was evaluated. On November 3, 89-666, VIP II, Aquarius II, Palmer/Prelude II, and Gulf annual rye had 70% or greater ground cover. The high ground cover of Gulf is attributed to quick germination and it's wide leaf blades, which shadow the ground. Rebel Jr. and Laser PT are slower to germinate and emerge, and thus had less ground cover percentage . By November 17, 1993, the annual rye had 91% mean ground cover, followed by the ryegrass entries of Palmer II/Prelude II, Prizm, Alliance blend, and the Sonoran blend. Rebel Jr. and Laser PT now had around 60% mean ground cover. By November 28, Palmer II/Prelude II, 89-666, and 91-S perennial ryegrasses had over 93% ground cover. By December 22, Helena, 89-666-Allaire II, Aquarius II, Sonoran Blend, and Palmer II/Prelude II had 95% or greater ground cover. Laser PT and Rebel Jr. had 72% and 63% ground cover, respectively . By January 21, 1993, all perennial ryegrasses developed 96% ground cover or more. Laser and Rebel Jr. had 86% cover, while the Gulf annual ryegrass had only 73% cover. This decline was attributable to mowing stress, poor low temperature performance from cold nights, and infestations of winter brown blight disease.

Turfgrass Color: Table 2.
On all evaluation dates, there were significant differences for color among overseeded entries for turf color.
At the beginning of the test, Gulf annual rye enjoyed the darkest green color on October 27, an artifact of quick emergence. Laser and Rebel Jr. had an extremely pale color and were indistinguishable from the background of the scalped bermuda. Within two and one half weeks, Rebel Jr. had developed the darkest green color (mean score = 8), followed by Aquarius II, VIP IIE and Prizm, which had color scores of 7.0. Laser PT, which is lighter in color, had a mean color score of 5.0, followed by Gulf annual ryegrass at 4.0. Rebel Jr. maintained mean color scores of 8.0 and 9.0 on November 10 and November 17. Fourteen ryegrasses had mean color score of 7.0, with three entries having lighter colors of 6.7 or less on November 10 .

By December 22, three ryegrasses had mean color score of 8.0 (Palmer II/Prelude II, Aquarius II, and Greenland). Rebel Jr. now had a mean color performance of 5.7, after some hard frosts. By one month later, Rebel Jr. had responded to fertilizer and cold acclimation and reached a color score 9.0, providing a very dark green forest color. Palmer II/Prelude II followed with a mean color score of 7.7. Gulf annual rye now slipped to 3.3 .

Club Choice, Alliance Blend, Prizm, 91-S, had color scores of 7.3 to 7.6 on February 24. Eight other entries had color scores of 7.0. On March 1, the color differences were not as extreme once the spring temperatures arrived and the turfs were now five months old. Palmer II/Prelude II, Pleasure, SS-33-DS, 91-S had color scores of 7.3 to 7.7. Rebel Jr. once again had a high color score of 9.0 on March 24, two weeks after fertilization. There were 12 other entries which had color scores greater than 7.0. Laser PT had a color score of 5.0, followed by Gulf Annual rye. The underlying bermuda in the check had greened up to a score of 7.0 by this time .

Rebel Jr., SS-33-DS and Prizm had color score of 8.0 or greater on April 21, while Laser PT and Gulf had mean color scores of 5.0 and 3.0, respectively. By May 21, most entries were holding good color, with Rebel Jr. having the highest score of 8.0. SS-33-DS, Prizm and Club Choice had mean color scores of 7.3. The Gulf Annual ryegrass had a low score of 2.0, while the non-seeded check, (which was showing need for fertilizer) received a mean color score of 5.0 . Color retention under increasing daytime heat stress was reflected by slightly lower color scores on June 10. SS-33-DS, Club Choice, Prizm, and Delaware Dwarf had mean color scores of 7.3 or greater.

For the entire test (average of all dates measured), color scores ranged from 2.5 for the non-overseeded check, to 7.3 for Rebel tall fescue. Palmer II/Prelude II was next with 7.0, followed by Prizm with 6.9. Eight other entries had overall mean color score of 6.5 to 6.8. These included Club Choice, SS-33-DS, Alliance Blend, Greenland, Sonoran Blend, 91-S, Aquarius II and Delaware Dwarf .

Turfgrass Quality: Table 3.
Quality scores were assigned on eight dates from November 28 to June 10. Overall cool season quality scores were derived by determining the overall quality scores on December 22, January 21, February 24, March 1, and March 24. On all dates, quality was significant among overseed entries.

On November 28, quality mean scores ranged from 1.0 (non-overseeded check) to 7.0. Aquarius II and 89-666 had early season quality scores of 7.0, followed by Sonoran Blend, and Palmer II/Prelude II which had mean scores of 6.7. The straight Laser PT and Rebel Jr. tall fescue were slower in establishment then the perennial ryegrasses or perennial ryegrass mixtures to establish full turf cover and development at five weeks after overseeding .

By December 22, there was less variation among plots. The test means for this date ranged from 1.0 (non-overseeded check) to 7.3 for Allaire II. Palmer II/Prelude II, Helena, Sonoran Blend, 89-666, and VIP IIE had color scores of 7.0, or greater. Rebel Jr. was slow to develop full ground cover, thus having a quality score of 4.7. Gulf annual rye and Laser Poa trivialis had mean quality scores of 4.3 and 3.7, respectively .

Quality scores ranged from 1.0 to 7.3 again on January 21, 1993. VIP IIE, 91-S and Southern Select had mean quality scores of 7.3. In late December and January, low temperatures in the mid 20F range, were recorded on ten dates. The chilling temperatures resulted in decreased quality scores due to reduced growth, some color loss, and some leaf tip burn. Aquarius II had the highest mean quality score on February 24. Fourteen other entries had scores of 6.0 to 6.7, while nine others had quality scores of 5.9 or less .

Warmer temperatures at the end of February clearly enhanced overall quality. This is the time of the year when the overseeded turfs usually bear their best performance with warm daytime temperatures, adequate sunlight, and cool nights. On March 1, Club Choice, Laser PT, 91-S, and Palmer II/Prelude II/Laser PT mixture had overall mean quality scores of 8.0. Greenland, Palmer II/Prelude II, and Prizm had mean scores of 7.7. Six other entries had overall quality scores of 7.0 to 7.3. Rebel Jr. had a mean quality score of 5.0. Annual ryegrass had a poor quality of 2.7 . Sonoran Blend had a mean quality score of 8.0 on March 24, followed by Palmer II/Prelude II, SS-33-DS and 91-S. Greenland, Allaire II, Prizm and Alliance Blend had scores of 7.0 to 7.3.

By May 21, the turf was experiencing daytime temperatures in the high 90's, approaching 100 on many occasions. 91-S had a mean quality score of 7.0, followed closely by Helena, Greenland, Delaware Dwarf, and Club Choice at 6.7. Rebel Jr. was now at 6.3, and the non-overseeded check had a higher mean quality score than the annual ryegrass. The final quality rating was taken on June 10, 1993. There were eleven entries with quality scores of 7.0 or greater. 89-666, CBS Blend, Helena, Club Choice, Medalist Gold, VIP IIE, and Prizm had quality scores of 7.3 to 7.7. Rebel Jr. tall fescue finished at 6.3, followed by ProStar, and Laser PR, at 6.0. The annual rye merely remained as mowed stems, with little or no leaf material remaining .

Results - Greens Test

Percent Cover: Table 4.
On November 3, percent ground cover mean scores ranged from 35-85%. Palmer II/Prelude II, had 85% cover, followed by 80/20 Jamestown/Laser, 85/15 Palmer II-Prelude II/Laser PT, Arizona Green, CBS Blend, and 80/20 Palmer II/Prelude II + Laser. The Poa trivialis and bentgrass entries averaged 35-47% ground cover . By November 10, the ratings were quite similar. At one month after seeding, the stolon development of the PT and bentgrass had started to help the plots "fill in". Arizona Green and 85/15 Palmer II-Prelude II/Laser PT had 90% cover, followed by the same mixture at the 80/20 ratio.

By November 28, six entries had 90% or more ground cover, with the lowest being 60% for Cypress Poa trivialis. By December 22, percent cover scores ranged from 80% to 98%, with the Jamestown/Laser mixture and Palmer II-PreludeII/Laser at the 85/15 ratio having higher percentage plot cover than the ryegrasses alone. By December 22, all entries had 90% or greater cover, with six entries having 96% or greater cover. The final percent cover evaluation was made on February 24. The ryegrass entries had slightly decreased in ground cover at this time, perhaps due to mowing stress and not having the advantage of developing stolons, as do the bentgrass and Poa trivialis .

Color: Table 5.
Color scores on October 27 (10 days after seeding) ranged from 1.0 to 6.7. The Poa trivialis and bentgrass were slow to germinate and thus have low scores, as mostly topdressing sand was seen at the plot surface. By November 3, the 80/20 mixture of Palmer II/Prelude II and Laser PT had a deep color of 9.0. Five other entries had scores of 7.0 to 7.3. The Laser PT, Trueline creeping bentgrass, Cypress PT and mixture of the two had inherently lighter, but attractive colors . By November 10, November 17, and November 28 overall color scores diminished, as the first cold night temperatures arrived and the perennial ryegrass blends had the darkest colors. By December 22, several hard frosts had occurred on the turf, and the overall color scores tended to decrease, especially for the bentgrasses, Poa trivialis, and the mixture of the two . After fertilization, color scores were much better on January 21, 1993. Palmer II/Prelude II and CBS blend had mean color scores of 9.0 and 8.7, respectively. The Trueline creeping bentgrasses had now reached a color of 8.0 .

On February 24, color scores ranged from 5.0 to 9.0, with the perennial ryegrasses having the darkest color. The decrease in color of the Trueline bentgrass could not be accounted for. Perhaps the application of iron chelate caused this bentgrass to loose color, temporarily . Color scores ranged from 4.3 to 9.0 on March 23. The Trueline bent would have the second highest mean color score (8.0), after the Palmer II/Prelude II perennial ryegrass blend. The Laser component of the Palmer II-Prelude II/Laser PT mixtures was now starting to dominate over the perennial ryegrasses, giving it the bright, light green color .

Color scores ranged from 4.3 to 8.7 on the April 22 rating date. The two ryegrass blends and Trueline bentgrass had the highest mean color score of 8.0 . By May 21, higher daytime temperatures were occurring and the ryegrasses were still showing good color. The Cypress Poa trivialis had a color of 7.3. The Trueline bentgrass was now light in color, and remained so till the end of the test. For the final rating, color scores ranged from 3.7 to 7.0 on June 10, 1993. Palmer II/Prelude II had the darkest color (7.0), followed by the CBS perennial ryegrass blend. The predominance of the Laser PT in the two Palmer II/Prelude II mixtures enhanced the light green color, also noting that the Poa trivialis showed symptoms of a foliar discoloration in red-orange patches during winter rains. Overall mean scores for all evaluations are provided .

Quality: Table 6.
Quality scores were taken on seven dates from November 28 to May 21. Quality scores include overall plot performance which is the culmination of texture, uniformity, density, smoothness, mowing tolerance, and consistency of color. Degree of color, has only minor influence.

Mean quality scores ranged from 3.3 to 6.7 on November 28, as overseed entries showed differences in emergence and ground cover establishment. The 85/15 mixture of Palmer II-Prelude II/Laser PT scored 6.6, followed by the 80/20 mixture of Jamestown fescue and Laser PT . By December 22, Palmer II/Prelude II and the 85/15 mixture of Palmer II-Prelude II/Laser PT had a mean quality score of 6.0, as well. The bentgrass, Poa trivialis, and mixtures of the two had the lowest quality scores, since these turfs were more juvenile and slower to develop stolons in the cool weather. By January 21, 1993, overall turfgrass quality improved. The scores ranged from 6.0 to 7.3. Quality scores ranged from 5.0 to 7.7 on February 24. The mixtures of 80/20 Palmer II-Prelude II/Laser PT, and 80/20 Jamestown fescue/Laser PT had the mean quality scores of 7.7 and 7.0, respectively .

With the permanent arrival of warm spring weather, the ryegrass blends provided the darkest color, from this date until the close of the test. These entries tended to have the more uniform surfaces, mowed well, and did not have the small areas of competing species, as was evident in the perennial ryegrass/Poa trivialis mixtures, which appeared more evident in the spring. This was apparent in the March 23 rating, and remained generally the condition, till the close of the test.

The final quality scores were taken on May 21. Trueline bent was making a strong transition to the underlying Tifgreen, while the Palmer II/Prelude II had slightly darker color than the CBS blend. The 80/20 mixture of Jamestown/Laser PT still remained strong under the heat, more so than the non-ryegrass entries . The overall quality scores is the grand mean for each entry, averaged across all evaluation dates . Readers should be advised that peak performance times may influence the selection of a specific overseeded selection. For example, if fall performance is critical, one may consider the ryegrasses for their quick germination. Heavy infestations of Poa annua favor a lighter color turf, such as Poa trivialis.

Foliar Discoloration
In March, small circular patches with bright red/orange rings appeared on the plots. Attempts to identify the cause of this condition were unsuccessful. This condition was assessed by visual estimates (0-100%) of each plot which showed the red discoloration. Plots which contained Poa trivialis only showed these symptoms. Both perennial ryegrass blends and the Trueline bentgrass did not show symptoms, as described here. Laser PT, the 80/20 mixture of Palmer II-Prelude II/Laser PT, and the Cypress PT and Trueline bentgrass mixture had 20% infestation levels (data not shown).

Ball Speed: Table 7.
Ball speed was measured on five occasions with a USGA stimpmeter after double mowing plots at 45 angles across the green. All clean-up-passes were made in the alleys, and not on plots. Six rolls were made, three in each lengthwise plot direction to minimize any mowing pattern effect.

February 3, 1993

The average green speed for all entries was 87, and mean ball speed ranged from 84-92 inches. Palmer II/Prelude II, provided the highest average ball speed of 92 inches, followed by Cypress PT, and the 85/15 ratio of Palmer II-Prelude II/Laser Poa trivialis at 89 inches. Jamestown fescue and Laser PT had a mean ball speed of 84 inches. Ball speeds decreased to a test mean of 78 inches on February 26. Palmer II/Prelude II had the highest mean speed of 81 inches, followed by Laser PT at 79 . On April 21, mean ball speed was 71 inches, with a range of 66 to 75 inches. Laser PT and Cypress PT had the highest ball speed of 75 inches. The ryegrass blends of Palmer II/Prelude II and CBS blend had mean speeds of 70 and 67 inches, respectively. The Trueline bent had a speed of 66 inches. On May 21, ball speed increased overall to 84 inches, with only a range of 6 inches among entries. Arizona Green had the top speed of 87 inches, while Cypress PT scored 81 inches.

Deep in transition, the final ball speeds were taken on June 1, 1993. The mean speed was 84 inches, with a range of 77 to 90 inches. The ryegrass blends (which had the highest amount of bermuda on May 25) had the slightly slower speeds, followed by Arizona Green and Palmer II/Prelude II ryegrasses .

STANDARD TEST (Fairway overseed)
for fall 1992 through spring 1993

Name PLS/M Sponsor
Laser (PT) 5 lb. Lofts seed inc.
Palmer II/Prelude II (PR) 25 lb. Lofts seed inc.
Rebel Jr. (TF) 20 lb. Lofts seed inc.
80% Palmer II/Prelude II(PR) 20% Laser (PT) 17 lb. Lofts seed inc.
Club Choice Blend (PR) 25 lb. Willamette seed
Sourthern Select Blend (PR) 25 lb. Willamette seed
Delaware Dwarf (PR) 25 lb. Ampac seed
Pleasure (PR) 25 lb. Ampac seed
Prostar (PR) 25 lb. Olsen-fennell seeds
91-S (PR) 25 lb. The Seed Connection
89-666 (PR) 25 lb. The Seed Connection
VIP II-e (PR) 25 lb. T.M.I.
Evening Shade + Affinity 25 lb. T.M.I
Allaire II (PR) 25 lb. T.M.I.
Aquarius II (PR) - Evening Shade 25 lb. T.M.I.
SS-33-DS (PR) 25 lb. Smith Seed
Prizm (PR) 25 lb. Zajac seeds
Medalist Gold (PR) 50% APM 25% Dandy 25% Target 25 lb. Northrup King
Alliance Blend (PR) 25 lb. Pure Seed Testing
25% Quick Start
25% Charger
25% Saturn
25% Brightstar
Sonoran Blend (PR) 33% Brightstar 33% Quick Start 25 lb. Pure Seed Testing
33% Charger
CBS Blend (PR) 33% Charger 33% Brightstar 33% Sunrye 25 lb. Pure Seed Testing
Greenland (PR) 25 lb. Pick Seed West
Helena (PR) 25 lb. Pick Seed West
Gulf annual ryegrass 25 lb. Oregon grown
Non-seeded check (Bermudagrass) ----- -----

GREENS TEST (Putting green overseed)
for fall 1992 through spring 1993

Name PLS/M Sponsor
80% Palmer II/Prelude II (PR) 23 lb. Lofts Seed Inc.
20% Laser (PT)
Laser (PT) 5 lb. Lofts Seed Inc.
85% Palmer II/Prelude II (PR) 25 lb. Lofts Seed Inc.
15% Laser (PT)
80% Jamestown (CHF) 18 lb. Lofts Seed Inc.
20% Laser (PT)
Palmer II/Prelude II (PR) 30 lb. Lofts Seed Inc.
Cypress (PT) 5 lb. T.M.I.
Trueline (creep. bent)
Cypress (PT) 5 lb. T.M.I.
Trueline (creep. bent) 5 lb. T.M.I.
Arizona Green 22 lb. International Seed
70% 9121 (PR)
20% Sabre (PT)
10% 90161 (col. bent)
CBS Blend 30 lb. Pure Seed Testing
33% Charger
33% Brightstar
33% Sunrye

Return to Turfgrass Research
[Cooperative Extension] [AgInfo] [UAInfo]

University of Arizona Cooperative Extension
4341 E. Broadway Road
Phoenix AZ 85040-8807
602-470-8086 FAX: 602-470-8092

Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director, Cooperative Extension, College of Agriculture & Life Sciences, The University of Arizona. The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.

All contents copyright © 2004. Arizona Board of Regents.