• Journal of Ecology and Environment
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• v.46 no.3
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• pp.190-201
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• 2022

Background: The introduction of new living modified (LM) crops may pose a latent threat to the biodiversity of each country. Here, we used sunflowers (Helianthus annuus L.) as a study system to investigate the potential for invasiveness of LM crops under different environmental conditions when released into a natural ecosystem in South Korea. We examined the seed germination, survival, and flowering of sunflowers under competition with wild plants at different sowing dates (March-December) and plot sizes (1 m × 1 m and 2 m × 2 m). Results: The germination rate showed a significant difference according to the sowing date. In addition, several sunflowers survived in plots with a high germination rate, which also led to a higher flowering rate. We found that the smaller the plot, the smaller the area available for inter-species competition, and the higher the number of surviving sunflower plants. The relative dominance and importance value of the species varied significantly between the sowing dates; in particular, sunflowers sown in March could compete with wild plants for longer than those sown on other sowing dates. Conclusions: These observations indicate that the potential for invasiveness of sunflowers differs depending on the environmental conditions and seed density at the time of release.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.74-74
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• 2005

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.203.3-203
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• 2003

No Abstract, See Full Text

• Proceedings of the Korean Society of Crop Science Conference
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• 1988.02a
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• pp.106-107
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• 1988

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2018.06a
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• pp.100-100
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• 2018

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.10a
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• pp.229-229
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• 2021

• Horticultural Science & Technology
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• v.35 no.1
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• pp.30-37
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• 2017

This study was conducted to determine the effects of various growth substrates on the growth and flowering of hydroponically grown Freesia hybrid 'Gold Rich'. Perlite, peat moss and a perlite: peat moss mixture (1 : 1 ratio, v / v) were used as the growing media. The greatest plant height before flower bud differentiation was attained using mixed medium compared to the others. The type of medium used did not influence leaf number, mineral content or SPAD value in leaves. Flowering began at 137 days after planting in mixed medium, which was 13 days earlier than in perlite medium. The whole plant fresh weight was 21.3 g heavier in mixed medium than in perlite medium (40.9 g). A similar result was obtained for shoot length, with the highest value (96.6 cm) obtained in mixed medium, i.e., 20 cm higher than in perlite medium (76.6 cm). Floret number per plant was also the highest in mixed medium (14.4), i.e., 1.7 - times higher than in perlite medium. Therefore, among the substrates tested in this experiment, we recommend using mixed perlite: peat moss medium (1 : 1 ratio, v / v) for hydroponic culture of freesia, as the use of this medium improved the physical properties of the plants, producing the best results in terms of plant growth and cut-flower quality.

• Korean Journal of Plant Resources
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• v.33 no.2
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• pp.106-115
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• 2020

In order to find out the relationship between spring phytophenological index and temperature index for the past nine years (2010~2018), this study identified the relationship between temperature changes and trends in spring phytophenological index of sprouting, flowering and leaf unfolding of Pinus densiflora Siebold & Zucc., Larix kaempferi (Lamb.) Carrière, Quercus mongolica Fisch. ex Ledeb., Rhododendron mucronulatum Turcz., Lindera obtusiloba Blume and Acer pseudosieboldianum (Pax) Kom. in Daegu Arboretum, Palgong mt., Juwang mt. and Gaya mt. The change in temperature was caused by an increase in the monthly average temperature between March and April compared to February for nine years, and the average temperature of Daegu Arboretum and Palgong mt. were higher by region. The sprouting, flowering and leaf unfolding were the fastest of the Lindera obtusiloba and the slowest of the Pinus densiflora for each species, and the fastest plant season in Daegu arboretum came. SPI (Spring Phytophenological Index) tends to advance by -1.267~-6.151/9 years, with the largest Pinus densiflora (-6.151/9 years), with the lowest rate of change for Rhododendron mucronulatum (-1.267 days/9 years). Species which shows significant values in sprouting, flowering and leaf unfolding is Rhododendron mucronulatum and Pinus densiflora, which correlate with the mean temperature of January to March. As a result of checking the time series change of SPI, the change rate in the four regions was all negative and the phenolocal index was all accelerating. Among them, the rate of change was greater in inland areas such as Daegu arboretum, Palgong Mt. and Gaya mt. and the rate of change was slightly lower in the case of Juwang mt., which is somewhat distant.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.74-77
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• 1996

This experiment was conducted to evaluated the effect of CM (plant growth regulator) treatment on flowering, pod maturing and root yield components of Astragalus membramaceus Bunge. Three dilution rates (60, 70 and 80 times) were sprayed at $3{\sim}4$ leave stage. As the results, flowering was delayed $25{\sim}35$ days than August 13 of control and higher dilution rates was more effective to delay flowering. At the havesting time, be compared with non-treatment, plant height reduced $7.6{\sim}18.9\;cm$ and number of matured pods were decreased $50.6{\sim}76.1$ by increasing dilution rates. However, weight of dry root per plant was increased to 29% and dry root yield per 10a was increased to 28% in dilution rates 70 compared with non-treatment.

• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.157-164
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• 2010

In Chrysanthemum ${\times}$ morifolium, 30 days of continuous short days (SD) are required for flowering. The effects of alternating short day (SD) - long day (LD) - SD treatments was tested in 5 daisy-like single cultivars, 'Limelight', 'Sunlight', 'Candle Light', 'Firebrand', and 'Twilight', Thee other decorative type cultivars, 'Spirit', 'SunburstSpriit', 'Mandalay', and 'Illini Harvest' was also included. Short day treatment was given for 30 days (control: 30SD) and 5 or 10 LD were interposed following 5 or 10 SD. Different responses were noticed when data from all cultivars were combined, showing that flowering was delayed and the number of ray florets were increased by 5 SD-10 LD-25 SD. The number of ray florets, 40 florets in 'Firebrand' and 60.8 florets in 'Candlelight' was increased significantly by 5 SD-10 LD-25 SD as compared to the control. There were no adverse effects by SD-LD-SD treatment, except for the delay in flowering time from 6 to 7 days. The number of ray florets in 'Illini Harvest' and 'Limelight' were, however, not increased by any SD-LD-SD treatments. Cultivar dependent responses should further be investigated in other newly available cultivars, and this information could be used to breed new cultivars.