Freezing Tolerance and Seasonal Color of Experimental Zoysiagrasses

Abstract

Meyer zoysiagrass {Zoysia japónica Steud.) is the most widely used cultivar in the transition zone of the United States due, in part, to its excellent freezing tolerance. Ten zoysiagrass progeny from crosses between Z. matrella (L.) Merr. x Z japónica or 'Emerald' [Z japónica x Z matrella (L.) Merr. var. pacifica Goudswaard] X Meyer, 'Cavalier' (Z. matrella), and DALZ 0102 (Z. japónica) were evaluated for (i) freezing tolerance, (ii) autumn and spring color, and (iii) a relationship between autumn color and freezing tolerance. Turfgrass cores were sampled from the field near Manhattan, KS, in October, December, or February and exposed to temperatures from -6 to -22°C in the laboratory. Lethal temperatures resulting in death of 50% of tillers (LTJQ) after 6 wk of recovery in the greenhouse ranged from -0.2 C to -12.2°C. All grasses were equivalent to Meyer in freezing tolerance except Cavalier on three of five sampling dates and one Z matrella x Z japónica progeny in December 2007, which were inferior to Meyer. Digital image analysis indicated that five progeny were superior to Meyer in autumn green color retention, but none were superior to Meyer in spring green color. Autumn color in 2007 was positively correlated (r = 0.40 to 0.58, p < 0.05) with LTgg in December 2007. However, autumn color was also positively correlated with color the following spring (r = 0.31 to 0.72). These progeny demonstrated good freezing tolerance and, in some cases, superior autumn color compared to Meyer. ). Abbreviations: of tillers. lethal temperature resulting in death of 50% Z OYSIAGRASS {Zoysia spp.) is a warm-season turfgrass commonly used on lawns and golf courses in the transition zone and the southern parts of the United States. Meyer {Z. japónica Steud.; Grau and Radko, 1951) has been the cultivar used predominantly in the transition zone since its release in 1951, in part because of its excellent freezing tolerance. However, Meyer is relatively slow to establish and more coarse textured than Emerald [Z. japónica x Z. matrella (L.) Merr. var. pacifica Goudswaard] or Z. matrella (L.) Merr. cultivars and has relatively slow recuperative rates (Fry and Dernoeden, 1987;Patton, 2009).Since the release of Meyer, researchers have developed and released numerous zoysiagrass cultivars, including the Z. matrella cultivars Cavalier (Engelke et al., 2002a), Diamond (Engelke et al., 2002b), and Zorro (Engelke andReinert, 2003). These cultivars have a finer leaf texture and better quality characteristics compared to Meyer; however, poor freezing tolerance has limited their use in the transition zone. In a controlled freezing chamber experiment.

Effect of Cultivation and Timing of Nitrogen Fertilization on Large Patch Disease of Zoysiagrass

“…Along with the disease implications, fall fertilization may also have implications for winter hardiness (15). Winter damage was not directly measured in this study, and no patterns related to fertility were observed anecdotally; however, Meyer is a particularly cold-tolerant variety (31,32). Therefore, spring or fall N applications to encourage recovery from large patch are limited in their potential efficacy for reducing large patch symptoms, and fall applications should be approached with caution regarding possible effects on winter hardiness.…”

“…This large patch study included only one zoysiagrass cultivar, Meyer. Different varieties and germplasm lines have varying rates of establishment (29), cold tolerance and greenup after winter dormancy (31,33), recovery from damage or sod harvest (30), and susceptibility to and ability to recover from large patch (28,32). Different cultivars may respond differently to various combinations of disease and cultural practices, including N fertility.…”

Relations between low temperature tolerance and color changes in fall and spring seasons of zoysiagrass (Zoysia japonica Steud.)

“…This suggests that Z. japonica, which became dormant later in the fall of 2008 also underwent green‐up later in the spring of 2009, which is different from the results of Okeyo et al . (). Although they found a positive correlation between fall color and spring color in four out of eight occasions, they also mentioned Meyer was always in the lowest statistical group for fall color and the best group for spring green‐up.…”

“…In this study, the correlation between low temperature tolerance and fall green color retention was similar to the results from two other studies on zoysiagrass (Okeyo et al . ) and buffalograss ( Buchloë dactyloides (Nutt.) Engelm.…”

“…Okeyo et al . () reported a positive relationship between low temperature tolerance and green color retention for 10 hybridization progenies by interspecific crossing between Zoysia matrella (L.) Merr. and Zoysia japonica Steud.…”