CHAPTERl. Effect of Fine Fescue Overseeding Dates on Buffalograss and Quality ABSTRACT

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1 CHAPTERl 45 Effect of Fine Fescue Overseeding Dates on Buffalograss and Quality Turf Color ABSTRACT Buffalograss [Buchloe dactyloides (Nutt) Engelm.] is native to North American Great Plains. It possesses excellent drought resistance and is a desirable turfgrass where water conservation is an issue. Buffalograss has a long winter dormancy, starting in early fall and extending to late spring. This winter dormancy period limits its potential use. Overseeding buffalograss turfwith a cool-season grass, like fine fescue (Festuca spp.), might enhance turfgrass quality and extend the period of green appearance for the turf. With this is in mind, a study was conducted to determine; I) Effect of seeding date and core cultivation on overseeding establishment; 2) Best fine fescue species for overseeding; 3) Effect of overseeded fine fescues on spring and fall turfgrass color retention; and 4) Impact of overseeded fine fescues on turfgrass quality. This study was conducted at the John Seaton Anderson Turfgrass Research Facility located near Mead, NE. The soil type was a Tomek silty clay loam (fine montmorillonitic, mesic Typic Arguidoll). Three fine leaf fescue species ['SR 3100' hard fescue (Festuca longifolia Thuill.), 'SR 3200' blue fescue (F. ovina L. glauca Lam.), 'SR 5100' Chewings fescue (F. rubra L. commutata Gaud.)] were overseeded into a mature 'NE ' buffalograss turf on three dates (fall, fall-spring, and spring), using two core cultivation treatments (i.e. single or double pass). Seeding dates for fall and spring seedings were 5 Sept and 15 May This study was repeated on 3 Sept and 20 May Data collected were shoot density, turfgrass quality, turfgrass green cover and turfgrass color. The experimental design was a randomized complete block with treatments in a 3 x 3 x 2

2 factorial arrangement and three replications. All species established better with fall 46 overseeding, but hard fescue (HF) established equally as well in fall-spring overseeding. Spring overseeding resulted unacceptable establishment for all three fescues studied. By September 2002, fine fescue and buffalograss stand compositions were of 80:20, 75:25, and 11:89 for fall, fall-spring, and spring seeding date treatments, respectively. The highest turfgrass quality and color ratings were obtained with the blue fescue (BF) treatment overseeded in fall. Green cover was above 80% for all fall and fall-spring treatments, when buffalograss was dormant in fall, except that the fall-spring overseeding treatment of Chewings fescue (CF) was 60 %. Core cultivation treatment had no effect on fine fescue density, turfgrass quality or color. Results from this study indicate that BF should be overseeded into mature buffalograss in the fall, when the buffalograss is dormant, to obtain improved turfgrass quality, green cover and color.

3 INTRODUCTION 47 Buffalograss is native to the Great Plains of North America and is from Mexico to Canada (Beetle, 1950). Buffalograss is a low-maintenance warm-season turfgrass species with heat and drought stress tolerance. It has a long winter dormancy that extends from early fall to late spring, and limits its widespread use as turfgrass (Johnson et ai., 2000). Fine fescues are low-maintenance cool-season grasses, which grow actively when buffalograss is dormant. Thus, overseeding fine fescues into buffalograss could potentially extend the green cover, quality and utilization of buffalo grass turf. Perennial cool- and warm-season grasses mixtures are not commonly used in turf due to difficulties in obtaining and maintaining the desired botanical composition (Davis, 1958; Beard, 1973; P.G. Johnson, personal communication, 2003). However, successfully maintained mixtures of cool- and warm-season grass exist in both pastures and turfgrass areas (Stoutemyer, 1953; Davis, 1958; Youngner, 1958; Wilkinson et all, 1968; Peterson and Moser, 1985; DiPaola and Spak, 1990; Pitman, 1999; P.G. Johnson, personal communication, 2003). Initial establishment and maintenance practices thereafter contribute to maintaining a desired mixture over time. Seeding date is the major determinant for successful establishment of cool-season grasses overseeded into a warm-season grass. If the new plants have the opportunity to develop an adequate root system, they will have a better chance of surviving the stresses associated with unfavorable growing conditions (Emmons, 2000), and can compete better with warm-season grasses in the mixture. Cool-season grasses establish best in late summer or early spring by taking advantage of favorable growing conditions (Beard, 1973). Seeding in the spring is usually less desirable due to shorter duration of favorable

4 growing conditions before summer stress, longer germination time caused by cooler 48 soil temperatures, and extensive weed competition (Emmons, 2000). Dernoeden (1998) recommended that fine fescues should be seeded between late Aug. and late Sept., but should not be seeded after 15 Oct. in the transition zone or 1 Oct. in northern regions. He also reported that spring seedings from Mar. 15 to May 15 are likely to produce inferior turfgrass stands, and summer seeding should be avoided altogether. Late summer seedings are usually preferred over spring due to favorable moisture and temperature conditions (Hull, 1948; DeFrance and Simmons., 1951; Dernoeden, 1998). After growing through the fall and during the following spring, the plants should be hardy enough to survive heat and drought stress (Emmons, 2000). A Sept. seeding date is recommended by many researchers (Beard, 1973; Diesburg, 1986; Reicher et ai., 2000; Dernoeden, 1998; Longer, 2000). Reicher et ai. (2000) studied seeding date effects on cool-season turfgrass establishment. They reported that the Sept. seeding produced the best establishment for all species tested in Indiana. Longer (2000) evaluated two seeding dates (mid-sept. and mid-oct.) for overseeding warm-season lawns with coolseason turfgrass species to provide year-long green cover in Arkansas. He found that the mid-sept. seeding date resulted in superior density and color ratings, established better, and competed more favorably with winter weeds. Overseeding with cool-season turfgrass too early in the fall often results in stand failure due to warm-season grass competition and increased disease incidence (Meyers and Horn, 1970; Ward et ai., 1974;). Late overseedings in fall are slow to establish and vulnerable to freezing and can result in poor germination, reduced stands and poor quality overseedings (Schmidt, 1970; Mazur, 1993).

5 Core cultivation (CC) improves the movement of air and water into compacted 49 soils and has shown to improve rooting (Engel, 1951). Soil compaction indirectly influences the growth of turfgrasses and, as a result, can alter plant competition (Watschke and Schmidt, 1992). In addition to improving air and water movement in soil, turfgrass cultivation is also used as a turfgrass overseeding or renovation practice providing good contact between the seed and soil without completely disrupting the existing turfgrass stand (Beard, 1973). Core cultivation reduces warm-season turf competition due to severing of rhizome and stolons if used prior to overseeding. Schmidt (1970) reported that when competition of the warm-season species was reduced and seeds had good contact with the soil, germination and initial development of seeds were enhanced. The objectives of this study were to determine; 1) Effect of seeding date and core cultivation on overseeding establishment; 2) Best fine fescue species for overseeding; 3) Effect of overseeded fine fescues on spring and fall turfgrass color retention; and 4) Impact of overseeded fine fescues on turfgrass quality.

6 MATERIALS AND METHODS 50 This study was conducted on a five-year-old stand ofne buffalograss at the John Seaton Anderson Turfgrass Research Facility located near Mead, NE. The soil was Tomek silty clay loam (fme montmorillonitic, mesic Typic Arguidoll). The stand was overseeded with SR 3100 hard fescue, SR 3200 blue fescue, and SR 5100 Chewings fescue at 20 g m 2 seeding rate. Two core cultivation treatments (i.e. single and double passes over the plots) were used prior to overseeding. Seed was applied in fall, spring or a split fall-spring treatment. The fall-spring split treatment received 109 m 2 in fall and 10 g m 2 in spring. Seeding dates for fall and spring seedings were 5 Sept and 15 May The study was repeated on 3 Sept and 20 May Different seedlots were used in 2001 and 2002 overseedings. The experimental design was a randomized complete block with three replications and treatments arranged in a 3 (species) x 3 (seeding date) x 2 (core cultivation) factorial. Treatment plot size was 1.5 m x 2.4 m. The buffalograss stand was mowed at 25 mm, clipping debris was removed, and treatment plots were core cultivated prior to overseeding. Turf was fertilized at 5 g N m- 2 with 16 N-IIP-I0K. Irrigation was applied to maintain a moist soil surface for three weeks after seeding, and rainfall was supplemented to 12 mm weekly by irrigation during the growing season. Turfs were mowed at 50 mm weekly with clippings returned. After establishment, turfs received 10 g N m- 2 season- 1 with applications made as 2.5 g N m- 2 in mid-may, 5 g N m- 2 in July and 2.5 g N m- 2 in Oct. with 38N-OP-OK- 12S sulfur coated urea. Soil samples were taken in Apr. prior to initiation of fertilizer applications and phosphorus and potassium were applied based on the soil test recommendations. The following data were collected during the course of this study:

7 51 1. Shoot density and stand composition was determined by counting fine fescue and buffalograss shoot numbers per 4000 mm 2 in May, July, and Sept. A frame that covers one plot was constructed with 5 x 8 grids. Four 100-mm diameter plugs were taken randomly from each plot. Plugs were returned to their original location after counting. 2. Turfgrass quality was rated biweekly in spring and fall and weekly during summer using a visual rating scale of 1 to 9 with 1 = poorest, 6 = acceptable and 9 = best. 3. Turfgrass green cover was rated biweekly using a visual estimate of %. 4. Turfgrass color was rated biweekly, using a visual rating scale of 1 to 9 (1 = straw brown, 6 = light green and 9 = dark green). Analysis of variance on all ratings and species counting was performed with PROC GLM procedure (SAS institute, 1999), when significant differences were detected means were separated using Fisher's protected least significant difference test (P<0.05). Hartley's (1950) F max test was performed to determine homogeneity of variance between the first and second trials of this study.

8 RESULTS and DISCUSSION 52 Data from the first and second trials could not be combined because the F max test (Hartley, 1950) resulted in rejecting the hypothesis of homogeneity of variance between the two trials. Thus, results of each trial are presented separately. FIRST TRIAL Fine Fescue and Buffalograss Shoot Counts A significant species by seeding date interaction was detected for fine fescue and buffalograss shoot densities for most assessment dates (Table 1.1). In the Sept evaluation, the fine fescue comprised 80 % of the tillers in the fall, and 75% in the fallspring treatments, while the spring treatment was 11 (Table 1.2). Blue (BF) and Chewings fescue (CF) had significantly (P<O.OI)better establishment with fall overseeding compared to spring or fall-spring overseeding. Hard fescue (HF) had no difference between fall or fall-spring overseeding treatments (Table 1.2). With these results in mind, overseeding in the fall would be best, since the added effort of split seedings in the fall-spring treatment did not increase fescue stand composition compared to fall treatments alone. Beard (1973), Diesburg (1986), and Demoeden (1998) recommended fall overseeding and research by Reicher et al. (2000), and Longer (2000) found fall overseeding to be superior to summer or spring seedings. In addition, weather conditions during the fall 2001 establishment were conducive to fine fescue establishment. Unseasonably warm air and soil temperatures in Nov 200 I allowed fine fescue more time to establish. Monthly air and soil temperatures and precipitation for 2001 and 2002 are presented in the Appendix Figures Al to A4.

9 One year after overseeding (Sept. 2002), there were no differences in fme 53 fescue shoot density in fall overseeding treatments. Fine fescue shoot numbers were around 87 per 4000 mm 2 in all fall overseeding treatments (Table 1.2). Although initial establishment of CF was lower than other fme fescue species due to reduced gennination and poor seed quality, it reached the same stand density as the other species by Sept This response was likely due to its high tiller number and vigorous growth during the growing season. Turfgrass species composition for BF and HF overseeded in either fall or fallspring followed the same trend for all evaluation dates. Percent fme fescue and turfgrass densities were highest in May at 92 %. From May to Sept., percent fine fescue declined to 85 % and 80 % for BF and HF, respectively. Buffalograss increased in composition during this time. However, total turfgrass shoot density decreased over this time (Table 1.2). Two factors may have contributed to this decline: a) unfavorably high temperatures for fescues, and b) increasing competition between BF, HF and buffalograss. Chewings fescue had a different trend than BF and HF treatments. Chewings fescue steadily increased from spring to mid July, and then slightly decreased while reaching a similar species composition and shoot density as the other fescue treatments overseeded in fall (Fig. A.5). Although early attempts to mix warm-season and cool-season grasses mostly failed (Davis, 1958; Beard, 1973), recent development of more aggressive cool-season grasses (Turgeon, 1991) may lessen the warm-season species advantage during summer stress periods. The very high percentage of blue fescue in the mixture treatments of this study causes some concerns. Buffalograss is reported to be less competitive than other

10 turfgrasses such as Kentucky bluegrass and bermudagrass (Riordan, 1991). Thus, in 54 mixed stands maintenance practices such as irrigation and fertilization should favor buffalograss in order to increase its competitive ability and provide a more balanced mixture. Warm-season turfgrasses are more tolerant oflow moisture than cool-season turfgrasses (Biran et ai., 1981; Gibeault et ai., 1989). At 50 % ET replacement, buffalograss was not stressed in mixtures with fine fescues in Utah (P.G. Johnson, Personal communication, 2003). In this study twelve mm/week irrigation was applied. Therefore, less irrigation might increase the competitiveness of buffalo grass over fine fescues in the BF treatments. Nitrogen was applied at 109 m -2 season- 1 to the plots, but higher N rates can increase the density, color, and quality of buffalo grass (Frank, 2000) giving buffalograss an advantage in competing against fine fescues during summer months. Late fall N fertilization (Oct.) that favors cool-season species (K.N. Morris, personal communication, 2003) should be omitted altogether and summer N application should be used to favor buffalograss. In addition, selection of more aggressive buffalograss cultivars may also contribute to a more balanced mixture as evidenced by seeding rate study under identical management practices, where NE buffalograss cultivar provided a balanced mixture. Fine fescues overseeded in fall or fall-spring dominated the mixture plots in this study. Similar results were found by P.G. Johnson (Personal communication, 2003). In his study, fine fescues in a fine fescue-buffalograss mixture study were above 80 % in Utah. Dunn et ai. (1994) showed that bermudagrass [Cynodon dactylon (L.) Pers.] -fine fescue mixtures had 69, 41, and 10 % Chewings fescue, creeping red fescue (F. rubra L. rubra) and hard fescue, respectively, three years after overseeding in Missouri. Davis

11 55 (1958) reported that percentage of Kentucky bluegrass (Poa pratensis L.) was 51 and 7 % in zoysiagrass (Zoysiajaponica Steud.), and bermudagrass mixtures, respectively. Among the fall-spring treatments, HF had the highest shoot density compared to BF and CF, and there was no difference between blue and Chewings fescue in terms of density on 7 Sept (Table 1.2). This result reflects difference among species shoot densities. Overall, spring overseeding resulted in an unacceptable level of establishment (Table 1.2). Spring seeding was not recommended due to problems in establishment (Demo eden, 1998; Emmons, 2000). Although poor, CF provided the best establishment among spring overseeding treatments (Table 1.2). This response might be due to faster germination ofsr 5100 CF (Lynch, 1996), which allowed it to establish better than BF and HF before summer stress occurred. From May to Sept., percent fine fescue decreased for BF and HF treatments, while CF treatments did not decline significantly. Core cultivation (CC) treatment (i.e. single versus double pass) did not influence fine fescue density (Table 1.1); however, double pass core cultivation (DPCC) reduced buffalograss density. Buffalograss shoot density in the single pass core cultivation (SPCC) treatments compared to DPCC treatments was 20 %, 37 %, 12 %, and 11% higher for Nov and May, July and Sept evaluation dates, respectively. Based on these results, SPCC treatments would be recommended. Turfgrass Green Cover There was a significant (P=O.O1) interaction between species and seeding dates for most dates (Table 1.3). All treatments exhibited significantly (P=O.O1) better turfgrass green cover with fall and fall-spring treatments compared to spring seeding

12 (Table 1.4). With the exception of fall-spring overseeding ofcf, all fall and fall-spring 56 treatments provided above 80% green cover when buffalograss was dormant in late fall (Table 1.4). From late July to late Sept. differences in turfgrass green cover among treatments decreased as buffalograss became more dominant (Fig. A6). For fall or fall-spring overseeding treatments, there was a decline in green cover from late July to mid Aug. (Fig. A6), which may have been caused by high temperature stress and competition between the fme fescues and buffalograss. Reduction in green cover as a response to higher than optimum temperatures has been reported for cool-season turfgrasses (Baker and Jung, 1968; Beard, 1973). Weather conditions at the research site during June and July 2002, included above average soil and air temperatures and below the 10-yr average precipitation (Figures Al to A.4). The BF and CF cultivars used in this study had lower densities in summer than in fall. Blue fescue had a denser stand than CF during the summer in Kansas (NTEP, 2000), indicating BF tolerates summer stress better than CF. For the CF treatment, highest turfgrass green cover was obtained with fall seeding. Turfgrass green cover by 28 Oct for CF treatments overseeded in fall was 26 % and 19 % higher than the plots overseeded in spring and fall-spring, respectively (Table 1.4). There were no significant differences between fall and fall-spring overseeding treatments for BF or HF treatments. For instance, green cover was 91 % and 87 % for fall and fall-spring BF treatments, respectively on 28 Oct (Table 1.4). In fall 2002, one year after overseeding, no significant difference in turfgrass green cover was observed among fall overseeding treatments (Table 1.4). Turfgrass green cover was 80 %,85 %, and 89 % for CF, HF, and BF treatments, respectively on

13 17 Nov (Fig. A.6). This result corroborates the shoot count data from this study 57 (Table 1.2). Among the fall-spring seeding treatments, no significant differences were observed between BF and HF treatments, and both had significantly more turfgrass green cover than CF, when buffalograss was dormant in fall (Table 1.4). Turfgrass green cover of CF treatment was 25 % less than BF and HF treatments on 28 Oct All spring overseeding plots, especially HF and BF compared with fall and fallspring overseeding treatments, resulted in poor establishment and less turfgrass green cover when buffalograss was dormant in fall 2002 (Table 1.4). However, CF treatment had significantly more green cover than BF and HF. By 28 Oct turfgrass green cover was 55,8, and 9 % for CF, HF, and BF treatments, respectively (Table 1.4). This result indicates that CF was more competitive than the other two fescues in spring overseedings. Core Cultivation treatment influenced turfgrass green cover when buffalograss was dormant (Table 1.3). The DPCC treatments exhibited more green cover than the SPCC treatments, but this response was opposite by early summer. The fall and fall-spring treatments extended the green cover of buffalo grass turf from less than five months to eight months, establishing a green turf from April to late November. Turfgrass Color A significant seeding date-by-species interaction was found for turfgrass color across all evaluation dates (Table 1.5). Turfgrass color was best in the BF treatment overseeded in fall or fall-spring (Table 1.6, Fig.A. 7). Two factors may have contributed

14 58 to this result. First, the blue-green color of the BF cultivar blends more closely with the buffalograss cultivar used in this study, than the color ofhf and CF cultivars. Second, BF performed better in mixtures in terms ofturfgrass color, during the summer when HF and CF showed more significant summer stress. This response may be due to the waxy leaf covering of SR3200 BF, which reduces transpiration (Lynch, 1996). This contributes to the more blue-green color it develops during summer stress periods (Lynch, 1996). There were significant effects of overseeded fescues on buffalograss turf grass color retention from October to late May, when buffalograss was dormant. On 17 Nov buffalograss turf that was not overseeded had a turfgrass color rating of I, while the BF treatment rated 7. As reported by Lynch (1996), 'SR3200' BF has good winter color retention, which contributed to improved green color of the mixture. Overall, the turfgrass color was improved over mono stand buffalograss due to the darker green color of fine fescues. Similar results were reported by P.G. Johnson (personal communication, 2003) in a Utah study. Due to the darker color of BF, turfgrass color ratings of BF treatments were higher than those of the non-overseeded buffalograss stand throughout the year. Fall turfgrass color rating compared to spring was higher for all mixture treatments and seeding dates (Fig. A.7). As summer progressed, temperature increased and fine fescues showed high temperature stress by July, resulting in an overall decline in turfgrass growth and color (Fig. A.7). The color ofhf and CF turned from mediumgreen to light-yellowish green, while BF maintained its blue-green color at the bottom of the leaf blade and light green to yellowish green color near cut ends of the leaf during the

15 59 summer stress period. The BF showed the least response to high temperature stress. As a result, the overall decline in turfgrass color was less for BF treatments than for HF and CF. By 9 Aug., when the lowest turfgrass color ratings were recorded, turfgrass color had declined to unacceptable levels for HF and CF treatments for fall and fall-spring overseedings (Table 1.6). The BF treatment overseeded in fall-spring and fall maintained acceptable ratings of 6.7 and 6, respectively. In late summer and early fall the fine fescues began to grow more actively again. This growth resulted in an increase in turfgrass color ratings for all treatments. Turfgrass color ratings on 9 Sept were 7.2 and 7 for CF, 7.2 and 7.3 for HF, and 8.5 and 8.7 for BF treatment for fall and fall-spring overseeding treatments, respectively (Table 1.6). Among the fall overseeding plots, BF treatment gave the best turfgrass color ratings across all evaluation dates. While not consistent, the difference between HF and CF treatments overseeded in the fall was not significant in respect to turfgrass color (Table 1.6). Turfgrass color ratings by 22 Sept were 7.8, 6.3 and 6.2 for BF, HF and CF treatments, respectively. Among the fall-spring overseeding treatments, again the BF treatment had the best turfgrass color, followed by the HF treatment. Among the plots overseeded in the spring, the CF treatment provided significantly higher turfgrass color ratings than the HF and BF, when buffalograss was dormant in fall (Table 1.6). This was probably due to better establishment of Chewings fescue in the buffalograss stand with spring overseeding. On the other hand, the difference between CF treatment and the other two mixture treatments was not significant during summer and early fall when buffalograss dominated the mixtures (Table 1.6).

16 60 With the exception of late fall, there were no significant differences between BF treatments overseeded in fall or spring! fall in terms ofturfgrass color (Table 1.6). Both seeding dates had significantly better turfgrass color ratings than spring overseeding. Turfgrass color ratings by 28 Oct were 7.7, 7.3 and 2.2 for fall, fall-spring and spring overseeding of BF treatments, respectively The fall-spring overseeding of HF provided better turfgrass color than fall overseeding from late June to September (Table 1.6). This response was due to a higher percentage of buffalo grass in fall-spring overseeding treatments, and subsequent better growth exhibited during the summer stress conditions. On 13 July 2002, HF treatments overseeded in fall had a turfgrass color ratings of 5.8, which was significantly lower than fall-spring treatments, which were rated as 6.7. No significant difference was detected between fall and fall-spring overseedings for the HF treatment with respect to turfgrass color in the fall. Both seeding dates had better turfgrass color ratings than the spring treatment. Turfgrass color ratings by 28 Oct were 5.8, 5.7 and 1.8 for fall, fallspring and spring overseedings, respectively For CF, the fall seeding date had a higher turfgrass color ratings than the other two seeding dates during fall. By 28 Oct. 2002, turfgrass color ratings for CF treatment were 5.8, 4.8 and 3.5 for fall, fall-spring and spring overseeding treatments, respectively. Fall-spring and spring overseeding dates gave significantly better turfgrass color ratings when CF exhibited significant summer stress. On 27 July 2002, turfgrass color ratings for CF treatments were 3.8,5.2 and 5.2 for fall, fall-spring and spring seeding plots, respectively.

17 From mid-may to mid-june, during establishment of fall-spring and spring 61 overseeding plots, significant interactions between seeding date and CC treatments were detected (Table 1.5). Fall-spring and spring plots that single pass core cultivated gave significantly higher turfgrass color ratings. This was probably because of the physical removal of more fescues (only in fall-spring plots) and buffalograss shoots from plots with DPCC treatment prior to the overseeding, thus leaving reduced stand and color. Although CC main effect was significant for turfgrass color (Table 1.5), it had a limited biological effect. Turfgrass Quality A significant seeding date-by-species interaction was found for turfgrass quality for all evaluation dates (Table 1.7). The fall seeding date compared to spring and fallspring seeding dates produced significantly better turfgrass quality during the fall when buffalograss was dormant (Table 1.8). The best turfgrass quality was obtained with the BF treatment overseeded in fall (Table 1.8, Fig. A.8). Several factors may have contributed to the improved quality of BF treatment, such as superior uniformity due to the consistent appearance of color, texture, and cover. The blue-green color ofbf cultivar blended better with the buffalograss cultivar used in this study, and better performance of BF during the summer also contributed to improved overall quality ratings for this treatment. Finally, the BF treatment maintained a very dense and attractive turf free from weeds, throughout the growing season. P.G. Johnson (personal communication, 2003) also reported that BF provided the best quality and improved

18 uniformity when mixed with buffalograss compared to CF and creeping red fescue in 62 Utah. Fall and spring turfgrass quality ratings were significantly better than summer turfgrass quality (Fig A.8). Decreases in turfgrass color and green cover caused by high temperature stress were the main reason for the decline in turfgrass quality. By 4 Aug. 2002, turfgrass quality ratings declined to less than 6.0 for all treatments, with the exception of the fall overseeded BF treatment, which was above the acceptable level at 6.3 (Table 1.8). With the decline in temperatures in late summer, turfgrass quality ratings improved for all treatments. On 9 Sept turfgrass quality ratings for fall overseeded CF, HF and BF treatments were 5.2, 7.2 and 8.5, respectively. Among the fall overseeding treatments, the BF treatment gave the best turfgrass quality followed by HF treatment, across all evaluation dates. On 22 Sept. 2002, turfgrass quality ratings were 7.8,6.7 and 5.2 for BF, HF and CF treatments, respectively (Table 1.8). Among the fall-spring overseeding treatments, the BF treatment gave the highest turfgrass quality ratings. While not consistent over all evaluation dates, the quality of the HF treatment was better than the CF treatment overseeded in fall-spring. Demoeden et al. (1998) reported that BF and HF maintained better turfgrass quality in summer than CF or creeping red fescue in Maryland. SR3200 blue fescue had better quality ratings than SR 5200 Chewings fescue in Nebraska under shade, whereas similar turfgrass quality ratings were observed in Iowa (NTEP, 2001) and Kansas under full sun (NTEP,2000). In spring overseeding treatments, establishment was poor and weed problem occurred, as noted by Demoeden (1998) and Emmons (2000), resulting in a patchy

19 appearance in BF and HF treatments. This response was not as evident in the CF 63 treatment. Although, none of the spring overseeding plots provided acceptable turfgrass quality by Oct. and Nov. 2002, the CF treatment provided better quality than BF and HF treatments. However, these differences were not significant, when buffalograss dominated the stand composition during summer and early fall. The fall overseeding date gave better turfgrass quality ratings for the BF treatment when buffalograss was dormant (Table 1.8). This result was due to higher BF percentage in the fall overseeding treatments, which provided more improved color and green cover. No significant differences were found between the fall and fall-spring overseeding treatments during summer and early fall (Table 1.8). Spring overseeding had the lowest turfgrass quality ratings compared to the other treatments. By 28 Oct. 2002, turfgrass quality ratings for the BF treatment were 7.5, 6.7 and 2.8 for fall, fall-spring and spring overseeding treatments, respectively (Table 1.8). For HF treatments, there were no significant differences in turfgrass quality between fall and fall-spring overseedings, and both overseeding dates provided better quality than the spring oversee ding, during fall when the buffalograss was dormant. Turfgrass quality ratings for the HF treatment were 6.0 for both fall and fall-spring and 2.2 for spring seeding dates, on 28 October The CF treatment did not provide acceptable turfgrass quality with any of the overseeding treatments when buffalograss was dormant. By 28 Oct. 2002, turfgrass quality ofcf was 4.5 for both fall and spring and 3.2 for fall-spring treatments. For the most part, the CF spring overseeding treatment had better quality ratings during summer

20 and early fall. This response was due to high buffalograss presence and more uniform 64 CF in these treatments. With the exception of early summer, core cultivation showed no significant effect on turfgrass quality (Table 1.7). Following overseeding in mid-may, spring and fallspring treatments SPCC plots had better turfgrass quality than DPCC. This response was due to removal of more shoots by the DPCC treatment prior to the overseeding, which resulted in reduced turfgrass cover, color and quality. Overall, CC had no apparent biological significance for turfgrass quality in this study. SECOND TRIAL Fine Fescues and Buffalograss Shoot Counts Similar to the first trial of this study, a significant species by seeding date interaction was found for both fescue and buffalograss shoot densities (Table 1.9). The results from this study again showed that fall overseeding was superior to the spring overseeding treatment (Table 1.10). As also seen in the first trial, Chewings fescue had better establishment with fall compared to fall-spring or spring overseeding treatments. For HF (similar to first trial) and BF there was no significant difference between fall and fall-spring oversee ding treatments. Both overseeding dates provided better establishment than spring overseeding (Table 1.10, Fig. A.9). Among the fall overseeding treatments, CF treatment had the highest percent fescue (33 %) followed by BF (23 %) and HF (17 %) treatments on 15 Sept Among the fall-spring overseeding treatments, both CF and BF established significantly better than HF (Table 1.10, Fig. A.9). Overall spring overseeding resulted in a poor establishment, similar to that observed in the first trial of this study. Percentage fescue was less than 5 % in HF and

21 65 BF treatments, while CF treatment had 19 % fescue in the stand on 15 Sept The quick germination ofcf 'SR 5100' enabled it to establish before the onset of high temperatures (Lynch, 1996). On the other hand, HF is slow to germinate and establish, thus, it requires a longer time to establish when compared to other fine fescues (Roberts and Seavey, 1993; Brar and Palazzo, 1995). Overall, core cultivation treatments did not impact fine fescue overseeding establishment, which was similar to the first trial of this study (Table 1.9). Turfgrass Green Cover All treatments were rated the same until Oct (Table 1.11). Treatments were individually rated after the buffalograss become dormant in October. Green cover was approximately 90 % and buffalograss dominated the mixture plots during summer and early fall. There were no significant interactions among treatments for turfgrass green cover for data collected between Oct. and Nov Species and seeding date main effects impacted turfgrass green cover during this time (Table 1.11). The highest percent green cover was obtained with the fall overseeding treatments (Table 1.12), similar results was found in the first trial. On 28 Oct. 2002, percentage of turfgrass green cover, averaged over fine fescue species, was 72, 64 and 49 % for fall, fall-spring and spring overseeding treatments, respectively. The highest percent green cover was obtained with CF treatment at 78 % followed by BF at 72 % and HF at 66 % on 28 Oct 2002 (Table 1.12). Core cultivation treatments had no significant effect on turfgrass cover (Table 1.11).

22 Turfgrass Color 66 Turfgrass color ratings were influenced by buffalograss color from June to October. Ratings were around 5.5 during this period (Table 1.14). Turfgrass color declined to 4.5 during mid-summer. Curvularia leaf spot [Curvularia lunata (Walde) Boedijn] and false smut (Cercospora seminalis Ellis & Everh.) were found on the buffalograss and brown patch (Rhizoctania solani Kuhn) was identified on the fescues at this time. Unlike the firs trial, there were no significant interactions among treatments for turfgrass color from October to November, but species and seeding date treatments influenced turfgrass color ratings (Table 1.13). Although BF provided the best color ratings in the first trial, the highest turfgrass color ratings were obtained with the CF treatment (Table 1.14) in this trial. As in the first trial of this study, fall overseeding provided the best turfgrass color followed by the fall-spring overseeding treatment. Core cultivation treatments did not influence the turfgrass color ratings (Table 1.13). Turfgrass Quality Until buffalograss started to enter dormancy, all treatment plots were primarily influenced by buffalograss growth. Because treatments were indistinguishable in terms of turfgrass quality, they were given the same quality ratings, until late Sept (Table 1.16). Overall turfgrass quality decreased during mid-summer due to disease activity on

23 buffalograss and fine fescue and high temperature stress on the fine fescue, species 67 (Table 1.16). According to the turfgrass quality ratings from Oct to mid-nov, there was no significant interaction among species, seeding date and core cultivation treatments for turfgrass quality (Table 1.15). Species and seeding date treatments had significant effect on turfgrass quality. Whereas BF gave a superior quality in the first trial, results in this trial indicated that CF treatment provided the best turfgrass quality (Table 1.16). This is because CF established faster than the other fescues in buffalograss. Providing more green cover and better color, CF resulted in better turfgrass quality in a short time following overseeding in fall Similar to the first trial, all treatments had the best turfgrass quality with the fall overseeding treatment with the fall-spring overseeding treatment the next best (Table 1.16). As in the first trial of this study, spring overseeding treatment resulted in very poor establishment and increased weed problems. As a result, patchiness was highly apparent in the turfgrass stand, since percent fine fescue was very low in the composition. Core cultivation treatments had no significant effect on turfgrass quality (Table 1.15).

24 CONCLUSION 68 Buffalograss has a long winter dormancy that limits its use as turf. Turfgrass green cover was extended from less than five months to eight months with the addition of fine fescue. Fall seeding resulted in the highest shoot density values for all fine fescue species in both trials. Therefore, fall should be recommended as the preferred time to overseed buffalograss with fine fescues under Nebraska conditions. In the first trial blue fescue was found to be the best companion grass to overseed buffalograss in establishing a perennial mixture. In the second trial, CF was found to be the best fine fescue species to overseed buffalograss. This response was primarily due to faster establishment of CF. However, the second trial was conducted for a shorter time than the first. These results may not represent the actual performances ofbf and HF over a longer period of observation. The BF treatments provided a very uniform, and above the acceptable level quality turf that extended the buffalograss color and quality ratings in fall and spring. Increased core cultivation did not have a significant effect on fine fescue establishment, color, or quality. Therefore one core cultivation pass would be recommended.

25 LITERATURE CITED 69 Beard, J.B Turfgrass: Science and culture. Prentice Hall. Englewood Cliffs, NJ Beetle, AA Buffalograss-native of the shortgrass plains. Univ. Wyoming Agric. Exp. Stn. Bull Laramie, WY. Biran, 1., B. Bravdo, 1. Bushkin-Harav, and E. Rawitz Water consumption and growth rate of 11 turfgrasses as affected by mowing height, irrigation frequency, and soil moisture. Agron. J. 73: Brar, G.S., and AJ. Palazzo Shoot and root development of tall and hard fescues in two different soils. 1. Environ. Qual. 24: Davis, R.R The effect of other species and moving height on persistence of lawn grasses. Agron : DeFrance, J.A, and J.A. Simmons Relative period of emergence and initial growth of turfgrasses and their adaptability under field conditions. Proc. Am. Soc. Hortic. Sci. 57: Demoeden, P.H Fine fescues on golf courses. Golf Course Management 66(4): Demoeden, P.H., M.A Fidanza, and 1.M. Krouse Low maintenance performance of five Festuca species in monostands and mixtures. Crop Sci. 38: Diesburg, K.L Dormant seeding study Iowa Turfgrass Res. Rpt. Publ. FG-451 : Dipaola, J.M. and D. R. Spalc Common bermudagrass and Kentucky bluegrass compatibility. p In Agronomy abstracts (ASAlCSSAlSSSA), Madison, WI.

26 Dunn, J.H., D.D. Minner, B.F. Fresenburg, and S.S. Bughrara Bermudagrass 70 and cool-season turfgrass mixtures: Response to simulated traffic. Agron.J. 86: Engel, RE Studies of turf cultivation and related subjects. Ph.D. diss. Rutgers Univ., New Brunswick, N.J. (Diss. Abstr ) Emmons RD Turfgrass science and management. Delmar Publishers Inc. Albany, NY. Frank, K.W Nitrogen allocation of three turfgrass species and turf-type buffalograss management. Ph.D. diss. University of Nebraska, Lincoln. (Diss. Abstr ) Gibeault, V.A., 1.L. Meyer, R. Autio, and R. Strohman Turfgrass alternatives with low water needs. Calif.Agric. 43:(6 ) Hartley, H.O The maximum F-ratio as a shortcut test for heterogeneity of variance. Biometrika 37, Hull, A.C., Jr Depth, season and row spacing for planting grasses on southern Idaho range lands. J. Am. Soc. Agron. 40: Johnson, P.G., T.P. Riordan, and 1. Johnson-Cicalese Low-mowing tolerance in buffalograss. Crop Sci. 40: Longer, D.E Green winter color for warm season lawns from overseeding with cool season species. TurfGrass Trends, 9(9): Lynch, S. (Ed.) Seed Specification Manual. 1 st ed. Seed Research of Oregon, Inc. Cascade Printing Company. Corvallis, OR Mazur, A.R Overseeding in transition. Golf Course Management 6(9):

27 Meyers, H.G., and G.C. Horn The two grass system in Florida. p In 71 1.R. Escritt (ed.) Proc 1 st Int. Turfgrass Res. Conf., Harrogate, England, July Sports Turf Res. Inst., Bingley, England. NTEP National FineleafFescue Test National Turfgrass Evaluation Program. Final Report NTEP National FineleafFescue Test National Turfgrass Evaluation Program. Final Report Petersen, J.L., and L.E. Moser Response of an irrigated cool- and warm-season grass mixture to nitrogen and harvest scheme. 1. Range Management 38: Pitman, W.D Response of 'Georgia 5' tall fescue-common bermudagrass mixture to season of nitrogen fertilization on the coastal plain. 1. Plant Nutr. 22: Reicher, Z.J., C.S. Throssell, and n.v. Weisenberger Date of seeding affects establishment of cool-season turfgrasses. HotrScience, 35: Riordan, T.P Buffalograss. Grounds maintenance, 2: Roberts, J., and D.C. Seavey Low maintenance turfgrass for landscape and commercial Agriculture. Coop. ext. Bull. March, Univ. of New Hampshire. SAS Institute Inc SAS/STAT user's guide. Release 8.0. SAS Ins. Cary, NC. Schmidt, R.E Overseeding cool season turfgrasses on dormant Bermudagrass for winter. P In 1.R. Escritt (ed.) Proc 1 st Int. Turfgrass Res. Conf., Harrogate, England, July Sports Turf Res. Inst., Bingley, England. Stoutemyer, V.T Grass combination for turfs. California Agriculture 7(11):9-10.

28 Turgeon, A.I Turfgrass management. Prentice-Hall, Englewood Cliffs, NJ. 72 Ward, C.Y, E.L. McWhirter, and W.R Thompson, Jr Evaluation of cool season turf species and planting techniques for overseeding Bermudagrass golf greens. P In E.C. Roberts (ed.) Proc 2 nd Int. Turfgrass Res. Conf., Blacksburg, VA June 1973 ASA. and CSSA, Madison, WI. Watschke, T.L., and RE. Schmidt Ecological aspects of turf communities. p: In D.V. Waddington, R.N. Carrow, and RC. Shearman (ed.) Turfgrass Science. Agron. Monogr. No 32. ASAlCSSAlSSSA, Madison, WI. Wilkinson, S. R, L.F. Welch, G. A. Hillsman, and W.A. Jackson Compatibility of tall fescue and coastal bermudagrass as affected by nitrogen fertilization and height of clip. Agron : Youngner, V.B Tall fescue-pensacola bahiagrass combination. Southern California Turfgrass Culture. 8:24.

29 Table 1.1. Analysis of variance (ANOV A) for fine fescue and buffalograss shoot density (frrst trial) from Nov to Sept Shoot density (Shoot number 4000 mm- 2 ) Fine fescue Buffalograss Evaluation date Source df 7 Nov. 25 May 13 July 7 Sept. 7 Nov. 25 May 13 July 7 Sept. Pr<F Rep 2 Species (S) 2 Core cultivation (CC) 1 NS NS NS ** * NS Seeding rate (SD) 2.* ** ** ** ** ** ** ** S x CC 2 NS NS NS NS ** NS NS NS S x SO 4 ** ** ** * NS * * CC x SO 2 ** NS NS NS NS.* NS NS S x CC x SO 4 NS NS NS NS NS NS., Significant at 0.05 and 0.01 probability levels, respectively; NS, not significant at 0.05 probability level.

30 Table 1.2. Mean number 4000 mm- 2 of fine fescue and buffalograss shoot densities (first trial) from Nov to Sept Evaluation date 7 Nov. 25 May 13 July 7 Sept. Overseeded Seeding Species date fescue buffalograss fescue buffalograss fescue buffalograss fescue buffalograss no.t no. no. no. no. no. no. no. Blue fescue Fall Fall-spr Spring Hard fescue Fall Fall-spr Spring Chewings Fall Fescue Fall-spr Spring LSD (0.05)t NSg t the number of fine fescue or buffalograss shoot in 4000 mm 2 t LSD for significant seeding date x species interactions. 9 NS is non significant at the 0.05level

31 Table 1.3. Analysis of variance (ANOV A) for turfgrass green cover (first trial) during 2001 and Evaluation Source df 23 Apr. 19 May I June 9 June 16 June 30 June 13 July 27 July Pr<F Rep 2 Species (S) 2 NS NS NS NS NS Core cultivation (CC) I NS NS NS Seeding rate (SO) 2 S x CC 2 NS NS NS NS NS NS NS S x SO 4 NS NS CC x SO 2 NS NS NS NS NS NS S x CC x SO 4 NS NS NS NS NS NS NS dates Evaluation dates Source df 9 Aug. 25 Aug. 9 Sept. 22 Sept. 8 Oct. 28 Oct. 17 Nov. Pr<F Rcp 2 NS NS NS NS NS NS Species (S) 2 NS NS NS NS NS Core cultivation (CC) I NS NS NS Seeding rate (SO) 2 NS NS NS NS NS NS NS S x CC 2 NS NS S x SD 4 NS NS NS NS NS NS NS CC x SD 2 NS NS NS NS NS NS S x CC x SD ~_._---_.._,,_._--,_.._--_.._-... Significant at 0.05 and 0.01 probability levels. respectively; NS. not significant at 0.05 probability level. -...J VI

32 Table 1.4. Mean turf grass green cover for fine fescue species x seeding date interaction (first trial) during Evaluation date Overseeded Seeding I speciest date Apr. May June June June June July July Aug. Aug. Sept. Sept. Oct. Oct. Nov. % Turfgrass green cover t CF Fall Spr Fall-spr HF Fall Spr Fall-spr BF Fall Spr Fall-spr LSD (0.05) NS'lI 5.9 NS 6.6 NS NS t BF = blue fescue; HF == hard fescue; CF = Chewings fescue. t Turfgrass green cover was rated visually on a 0 to 100 % scale. 9 LSD for significant seeding date x species interactions. 'lins is non significant at the 0.05 level

33 Table 1.5. Analysis of variance (ANOV A) for turf grass color (first trial) during Evaluation dates Source df 23 Apr. 19 May 1 June 9 June 16 June 30 June 13 July 27 July Pr<F Rep 2 Species (S) 2 ** ** ** ** ** ** ** ** Core cultivation (CC) 1 NS NS * * NS NS ** ** Seeding rate (SD) 2 ** ** ** ** ** ** ** ** S x CC 2 NS NS NS NS NS NS NS * S x SO 4 ** ** ** ** ** ** ** ** CC x SO 2 NS ** ** * * NS NS NS S x CC x SO 4 NS NS NS NS NS NS NS NS Evaluation dates Source df 9 Aug. 25 Aug. 9 Sept. 22 Sept. 8 Oct. 28 Oct. 17 Nov. Rep 2 Species (S) 2 ** ** ** ** ** ** ** Core cultivation (CC) 1 * NS NS NS NS NS * Seeding rate (SO) 2 ** ** ** ** ** ** ** S xcc 2 NS NS NS NS NS NS NS S x SO 4 ** ** ** ** ** ** ** CC x SO 2 NS NS NS NS NS NS NS S x CC x SO 4 NS NS NS NS NS NS NS *,**Significant at 0.05 and 0.01 probability levels, respectively; NS, not significant at 0.05 probability level. Pr<F --.J --.J

34 Table 1.6.Mean turfgrass color for species x seeding date interaction(firs trial)during Evaluation date Overseeded Seeding speciest date Apr. May June June June June July July Aug. Aug. Sept. Sept. Oct. Oct. Nov. Turfgrass color t CF Fall Spr Fall-spr HF Fall Spr Fall-spr BF Fall Spr Fall-spr LSD (0.05) ~ t BF = blue fescue;hf = hard fescue;cf = Chewings fescue. t Turfgrass color was rated from 1 to 9, with 1 = straw brown, 6 = lightgreen and 9 = dark green. ~ LSD for significantseeding date x species interactions. -...) 00