• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.3
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• pp.23-38
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• 2015

The study was initiated with Kentucky bluegrass (KB, Poa pratensis L.) to investigate germination and early establishment characteristics of new cultivars for a practical application to turfgrass establishment such as parks, athletic field and golf course etc. Fifteen cultivars were evaluated in different experiments. An alternative condition for a KB germination test required by International Seed Testing Association (ISTA) was applied in Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$ (natural conditions). Seed germinating vigor, germination speed and germination peak time were measured in both experiments. Significant differences were observed in seed germinating vigor, germination speed and germination peak time. Seed germinating vigor was variable with different environments and cultivars. It was 75.25 to 89.50% under ISTA conditions and 75.75 to 90.25% under natural conditions. There were considerable variations in early germination characteristics among KB cultivars according to different environments. Early germination characteristics showed that all cultivars were 3 to 5 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 50% to 80%, was much faster with 'Midnight II', 'Excursion' and 'Midnight' under ISTA conditions. But it was faster with 'Midnight II', 'Excursion' and 'Odyssey' under natural conditions. Differences was also observed in germination peak time with cultivars and growing conditions. It ranged 5.94 to 14.88 days under ISTA conditions and 4.71 to 13.06 days under natural conditions. Regardless of the environment conditions, the shortest cultivars were 'Odyssey' and 'Midnight II'. The longest ones were 'Nuglade' under ISTA condition and 'Moonlight' under natural conditions. Considering germinating vigor, germination speed and germination peak time, 'Midnight II', 'Excursion', 'Midnight', and 'Odyssey' were regarded as excellent cultivars under ISTA conditions in terms of early establishment characteristics, while 'Midnight II', 'Excursion', 'Odyssey', and 'Courtyard' under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for investigating the early germinating vigor, germination speed and germination peak time. Also, a proper cultivar selection and comprehensive site analysis for the growing environmental conditions should be done before turfgrass establishment such as golf course construction.

• Asian Journal of Turfgrass Science
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• v.17 no.1
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• pp.1-12
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• 2003

Research was Initiated to investigate germination characteristics of cool-season grasses (CSG). Several turfgrasses were tested in different experiments. Experiments I and III were conducted under a room temperature condition of 16$^{\circ}C$ to 23 $^{\circ}C$ and under a constant light condition at 25 $^{\circ}C$, respectively. An alternative environment condition that is a requirement for a CSG germination test by International Seed Testing Association (ISTA) was applied in the Experiment II, consisting of 8-hr light at 25 $^{\circ}C$ and 16-hr dark at 15 $^{\circ}C$. In each experiment, data such as early germinating vigor, germination speed and germination rate were evaluated. Six turfgrass entries were comprised of two varieties each from Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), and tall fescue (TF, Festuca arundinacea Schreb.), respectively. Significant differences were observed in early germinating vigor, germination speed and germination rate. Early germinating vigor as measured by days to 70% seed germination was variable according to environment conditions, turfgrasses and varieties. It was less than 6 days in PR and 6 to 9 days in TF. However, KB resulted in 11 to 13 days under an alternative condition and 11 to 28 days under a room temperature condition. The germination speed was fastest in PR of 7 to 10 days and slowest in KB of 14 to 21 days. However, intermediate speed of 10 to 14 days was associated with TF. There were considerable variations in germination rate among turfgrasses according to different conditions. Generally, PR and TF germinated well, regardless of environment conditions. However, a great difference was observed among KB varieties, when compared with others. Under a room temperature condition, total germination rate was 71.0% in Midnight and 77.7% in Award. And it increased under an alternative condition, which was 81.7% and 91.7% in Award and Midnight, respectively. However, the poorest rate was found under a constant temperature condition, resulting in 18.0% in Award and 15.3% in Midnight. These results suggest that an intensive germination test required by ISTA be needed prior to the decision of seeding rate, including early germinating vigor and germination speed as well as total germination rate. KB is very sensitive to environment conditions and thus its variety selection should be based on a careful expertise.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.274-282
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• 2013

Research was initiated to investigate early germination and establishment characteristics of perennial ryegrass (PR, Lolium perenne L.). An alternative condition was applied in Experiment I with 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA condition). Experiment II was conducted under $5^{\circ}C$ to $25^{\circ}C$ (natural condition). Significant differences were observed in germination percentage, germination speed and germination peak time. Seed germinating vigor was 66.00 to 93.75% under ISTA and 66.25 to 93.50% under natural conditions. Germination speed, measured as days to germination of 50% through 90%, was much faster with 'Pennant II', 'Brightstar II', 'Sonata' and 'Accent II' under ISTA conditions. But it was faster only with 'Pennant II' and 'Brightstar II' under natural conditions. Germination peak time ranged 1.48 to 5.65 days under ISTA, while 2.17 to 10.63 days under natural conditions. Regardless of growing conditions, the shortest cultivars in peak time were 'Sonata', 'Pennant II', and 'Brightstar II' and the longest one 'Revenge GLX'. Considering germinating vigor, early germination speed and germination peak time, 'Pennant II', 'Brightstar II', 'Sonata' and 'Accent II' were regarded as excellent cultivars under ISTA conditions, while 'Pennant II' and 'Brightstar II' under natural conditions.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.235-248
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• 2017

This study was initiated to investigate seed germinating vigor, germination speed, and establishment characteristics of Festuca species under natural conditions ($5-25^{\circ}C$). Germination rate was 62.0% in CRF 'Audubon' to 97.0% in TF 'Olympic Gold'. It was greater with TF over fine-type fescues, being TF>SF>CF, HF>CRF. The germination speed, measured as days to seed germination of 50% through 80%, was fastest with TF, medium to high with CF, medium with HF and SF, and slowest with CRF. However, it was approximately 4 days slower under natural conditions, as compared with that under alternative conditions ($15-25^{\circ}C$). Germination peak time was much faster with TF. It ranged from 0.73 to 1.84 days with TF, being 1.45 days in average. But it varied with 2.16 to 11.75 days among fine-type species. The peak time was longer in order of SFCF>SF>HF>CRF.