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  • Author or Editor: R. E. Gaussoin x
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Abstract

Seed of Poa annua var. reptans (Hauskins) Timm, (annual bluegrass) and Agrostis palustris Huds. ‘Penncross’ (creeping bentgrass) were treated at planting with flurprimidol at rates of 0.00, 0.28, 0.56, 0.84, 1.12, 1.68, and 2.24 kg·ha−1. Data were collected on germination of each species. Flurprimidol rates greater than 0.56 decreased germination for both species. Chemical name used: α-(1-methylethyl-α-[4-(trifluoro-methoxy)phenyl]-5-pyrimidine methanol (flurprimidol).

Open Access

A method for measuring soil water potential in field soils was adapted for use in turfgrass soils. The system uses tensiometers installed flush with the soil surface and permits a measuring depth as shallow as 2.5 to 5.0 cm. Water potential within a tensiometer was measured with a portable pressure transducer. Linear relationships between water potential measured with mercury manometers or vacuum gauge-equipped tensiometers and the pressure transducer were obtained (r2 = 0.99 and 0.97, respectively). The system accurately measures soil water potential of turfgrass soils, while permitting routine cultural practices to be performed.

Free access

A simple marker technique called sequence-related amplified polymorphism (SRAP) provides a useful tool for estimation of genetic diversity and phenetic relationships in natural and domesticated populations. Previous studies and our initial screen showed SRAP is highly polymorphic and more informative when compared to AFLP, RAPD and SSR markers. In this study, applicability of the SRAP markers to obtain an overview of genetic diversity and phenetic relationships present among cool-season (C3) and warm-season (C4) turfgrass species and their relationship with other Gramineae species were tested. Phenetic trees based on genetic similarities (UPGMA, N-J) were consistent with known taxonomic relationships. In some cases, well-supported relationships as well as evidence by genetic reticulation could be inferred. There was widespread genetic variation among C3 and C4 turfgrass species. In Dice based cophenetic matrix, genetic similarities among all species studied ranged from 0.08 to 0.94, whereas in Jaccard based cophenetic matrix, genetic similarities ranged from 0.05 to 0.85. C3 and C4 species were clearly distinguishable and a close relationship between italian ryegrass and tall fescue were obtained based on SRAP. Genome structures of turfgrasses are comparable to other Gramineae species. This research indicates that the SRAP markers are useful for estimating genetic relationships in a wide range of turfgrass species. The SRAP markers identified in this study can provide a useful reference for future turfgrass breeding efforts.

Free access

Abstract

The response of bermudagrass clones (Cynodon spp.) to reduced light intensity was determined in a greenhouse experiment. Thirty-two phenotypically diverse bermudagrass clones from broad geographic origins were subjected to two light treatments. The high-light treatment consisted of sunlight supplemented with fluorescent and incandescent light banks (160 µmol·s–1·m–2). The low-light treatment was a 90% reduction of the high-light treatment (16 µmol·s–1·m–2). Visual color, leaf length, stem internode length, stem elongation, chlorophyll concentration, and dry weight were measured. Bermudagrass clones responded to reduced light by exhibiting shorter leaves, shorter stem internodes, reduced green color, lower chlorophyll concentration and decreased dry weights. ‘Boise’, ‘No Mow’, ‘R9-P1’, ‘NM2-13’, and ‘NM3’ have been identified as being moderately insensitive to reduced light intensity, and data suggest enough variability exists to select for shade tolerance in bermudagrass.

Open Access

Golfers are demanding increased ball roll distances on a daily basis, but cultural practices to achieve this often are detrimental to the green. One option for increasing ball roll distance without altering cultural practices may be to select creeping bentgrass genotypes that provide less resistance to ball roll. Studies were conducted at the John Seaton Anderson Turfgrass and Ornamental Research Facility near Ithaca, Neb., and at the Rocky Ford Turfgrass Research Facility in Manhattan, Kans., to determine genotype and seasonal influences on golf ball roll distance. Eighteen creeping bentgrass (Agrostis palustris Huds.) genotypes were evaluated. Genotype was not a significant source of variability, but the location × season interaction was. Significant seasonal differences in ball roll occurred at both locations. Ball roll distances for spring, summer, and fall were 98, 15, and 31 cm greater at the Nebraska test location than at the Kansas site. Correlations between turfgrass visual quality and ball roll distance were not significant. Therefore, the use of genotypes exhibiting high turfgrass visual quality will not necessarily result in longer ball rolls. Since there were no season × genotype or genotype × location interactions, ball roll distance on genotypes at each location changed similarly with season. Genotype selection appears to have little influence on ball roll distance under the conditions tested at these two locations.

Free access

Two systems of relay-intercropping muskmelons (Cucumis melo L.) with Scotch pine (Pinus sylvestris L.) Christmas trees using black plastic mulch and drip irrigation were evaluated for their potential to improve cash return. Returns ranged from a high of $26,200/ha for plastic mulch-drip irrigation and a selling price of $l.00/melon to a low of $6900/ha for bare ground-drip irrigation and a selling price of $0.40/melon. The benefit-cost index ranged from 24 to 3.4, depending on the system evaluated. Pine growth apparently was impeded by plastic mulch; however, increased yields of melons grown under plastic mulch may offset the slight decrease in pine growth.

Free access