Meson Masses in the Unquenched Quark Model

A novel approach to calculating coupled-channel effects for bottomonium in the 3P0 framework using realistic wavefunctions is introduced in which the physical state is expanded in a basis set of harmonic oscillators. Other techniques of solving the unquenched system are also presented including perturbative, simple harmonic oscillator and unique valence approximations. The resulting (spin-averaged) mass shifts are calculated for an nS → 1S +1S transition and compared across the separate methods. It is determined that the largest effect on the mass shift across the various approaches is the accu-rate treatment of the wavefunction, which causes significant deviations from the simple harmonic oscillator approximation near threshold. It is also found that the inclusion of mixing between valence states due to meson loops has no effect at ground state energies but induces small differences at higher lying states. While conclusions are drawn about the relative effect each of the methods presented have on determining the mass shift due to unquench-ing, further research is suggested for other transitions to be assured in such conclusions

Using Ethephon for Seedhead Suppression of ‘Innovation’ Zoysiagrass

The performance of ethephon (Proxy) on seedhead suppression of ‘Innovation’ zoysiagrass was evaluated during the 2019–2020 growing season in Manhattan, KS. Treatments evaluated Proxy applied in a single autumn application at 5 fl. oz./1,000 ft2 on multiple dates between August 28 and November 26, 2019. Seedhead suppression ranged from 15% (application on November 1) to 82% (applied on September 4). Dates between September 4 and October 3 were the optimum application window for ethephon application on Innovation zoysiagrass as seedhead suppression was at least 62% with minimal turf injury occurring

Evaluation of Selected Large Patch-Tolerant Zoysia spp. for Performance in Kansas

Turf quality characteristics and large patch incidence of ten selected experimental zoysiagrass genotypes were evaluated during the 2018–2019 growing season in Manhattan, KS, and establishment rate of the same ten was evaluated in Olathe, KS. Although plots were inoculated with Rhizoctonia solani (AG 2-2 LP) in September 2018 in Manhattan, no large patch occurred. However, the genotypes showed vari­ability in turf performance measured by turf quality, spring greenup, fall color reten­tion, and genetic color. In Olathe, KS, at Shadow Glen Golf Club, the ten genotypes were planted on June 17, 2019. The range in visual ground coverage on September 27, 2019, was 63.3 to 92.7%

Identification of Cold-Hardy Zoysiagrass Genotypes for Tees and Greens in the Upper Transition Zone

Since the summer of 2017, 1,376 experimental zoysiagrass genotypes have been evaluated for winter survival in Olathe, KS, in an attempt to identify high quality, fine-textured types that survive in Kansas. After planting 458 progeny in the field in August 2017, only 17 experimental progeny survived when evaluated in spring 2018 (4%). In 2018, those 17 survivors were included with a new planting of 918 experimental progeny. In spring 2019, it was determined that 70 genotypes survived (8%). The 70 surviving progeny were transferred to a new, adjacent plot area in June 2019 and they varied in leaf texture (3.0 to 7.5 on a 1 to 9 scale; 9 = finest) and vigor (2.0 to 8.0 on a 1 to 9 scale; 9 = most vigorous) when visually rated on September 27, 2019. In 2020, all 70 progeny survived and showed variation in spring greenup in April (1.0 to 5.0; 1 to 9 scale, 9 = completely green). By early summer of 2020, best performing progeny with superior cold-hardiness and quality will be propagated for evaluation in larger plots starting in 2021

Evaluating Large Patch-Tolerant and Cold Hardy Zoysiagrass Germplasm in the Transition Zone

More than 2,800 zoysiagrass progeny, all having a single parent in common that exhibited tolerance to large patch, were evaluated in several transition zone states for quality characteristics and large patch tolerance. From these evaluations conducted over several years, 10 progeny have been identified for further evaluation that have good quality and large patch tolerance that is superior to Meyer zoysiagrass

Selection of New Zoysiagrass Genotypes for Golf Course Fairways, Greens, and Tees in the Upper Transition Zone

A set of 70 experimental zoysiagrass genotypes along with three standards, ‘Meyer,\u27 ‘Innovation,\u27 and ‘KSUZ 1201,\u27 were evaluated for turf performance in the northern transition zone. The genotypes were previously selected from a set of 935 progeny that resulted from pairwise crossings of cold-hardy zoysiagrass parents with fine-textured, under-utilized zoysiagrasses. All 70 progeny survived the winter of 2019–2020 and thus were evaluated based on their turf performance. The preference of selection was based first upon spring green up ratings, followed by leaf texture (finer preferred), vigor, turf quality, and wilt during dry down. A total of 20 best progeny were selected and harvested for propagation on October 12, 2020. Only one geno­type, ‘6844-31’ had a texture rating of 8.0 (1 to 9 scale; 9 = finest texture) and four other genotypes had texture ratings higher than 7.0 among the selected 20 best progeny. The progeny will be established in larger replicated plots at several locations including Kansas State University Olathe Horticulture Center, Olathe, KS, starting in the summer of 202

Evaluating Zoysiagrass-Tall Fescue Mixtures in Kansas

Water conservation is increasingly important when selecting turfgrasses. Zoysiagrass (Zoysia japonica), a C4 grass, is more drought resistant than C3 grasses. However, there is some resistance to the use of zoysiagrass in lawns and golf courses due to its extended dormant period when turf is brown. The objective of this study was to evaluate mowing height, and tall fescue seeding rate and time for establishment of a mixed stand with seeded zoysiagrass. Seeding zoysiagrass and tall fescue together in June generally resulted in a less uniform mixture than seeding zoysiagrass in June and then seeding tall fescue in September. Tall fescue seeded in September at 8 lb of pure live seed (PLS)/1,000 ft2 resulted the most uniform mixture of the two species

Brown Patch Occurrence in a Zoysiagrass-Tall Fescue Polystand Compared to a Tall Fescue Monostand

Research has demonstrated that polystands of zoysiagrass and tall fescue can be established successfully, with the potential to provide a high quality turfgrass stand with reduced inputs. Our objective was to determine whether mixing zoysiagrass with tall fescue will reduce brown patch severity while maintaining overall accept­able quality. Studies were established at the Rocky Ford Turfgrass Research Center in Manhattan, KS. In the split-plot design, natural infection by Rhizoctonia solani or a fungicide-treated control was the whole plot treatment factor and species (tall fescue monostand and the zoysiagrass/tall fescue mixture) were subplots. During July and August 2016 and 2017, when hot, humid weather triggered brown patch, excessive irrigation was applied to promote brown patch. Disease severity was mea­sured by visual ratings and digital image analysis; number of leaves in each plot that were infected was recorded using a grid. The mixed stand then showed less plot area affected by brown patch disease compared to the monostand of tall fescue

Evaluating Large Patch-Tolerant and Cold Hardy Zoysiagrass Germplasm in the Transition Zone

A Zoysia japonica genotype, TAES 5645, that exhibited partial resistance to large patch in preliminary studies conducted by our collaborators at Texas A&M University, was used as a breeding parent at Texas A&M and crossed with 22 cold hardy zoysiagrasses, resulting in 2,858 progeny. These progeny were evaluated for cold hardiness and agronomic traits (establishment rate, overall quality, spring green up, leaf texture, and genetic color) in Manhattan, KS; West Lafayette, IN; and Dallas, TX; from 2012 to 2014. This report focuses on the Manhattan, KS, results. From this work, 60 progeny were identified for further evaluation in larger plots. In fall 2016, ‘Meyer’ (42% of plot area affected) had more large patch than all zoysiagrass progeny (0 to 23%). In spring 2017, Meyer had 33% large patch, higher than most progeny. Among this group of experimental zoysiagrasses, there appear to be promising progeny that have good winter hardiness, resistance to large patch, and improved turf quality characteristics. Data collection is ongoing