• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.1
• /
• pp.22-29
• /
• 2020

Rice is very sensitive to high temperatures during the reproductive stage, particularly during the flowering and anthesis periods. To determine how high temperatures result in sterility during the flowering period in Korean rice cultivars, groups of 11 cultivars were subjected to different temperature regimes (24, 28, 30, and 33℃) during the flowering stage using sunlit phytotrons. At an average of 33℃, all 11 rice cultivars reached anthesis earlier than at the other temperatures. Microscopy analyses revealed significant differences in pollen germination and pollen viability in cultivars grown at 33℃ compared to those cultured at lower temperatures. At 33℃, the cultivars had significantly lower fertility rates (47% reduction) than cultivars grown at 24℃. These findings are important as rice pollination and fertility depend on the pollen viability and germination. The present study shows that rice fertility is negatively affected by excessively high temperatures.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.24 no.5
• /
• pp.15-23
• /
• 2021

This study was carried out to suggest an appropriate plant combination by evaluating the growth of flowering ground-cover plants planted with Festuca glauca 'Eljiah Blue' on the roof-top environment. As for the plant materials, Allium senescens and Chrysanthemum coreanum which are shorter than Festuca glauca 'Eljiah Blue' and Sedum takesimense and Agastache rugosa which are taller than Festuca glauca 'Eljiah Blue' were selected. Festuca glauca 'Eljiah Blue' was planted on Conrol, and Festuca glauca 'Eljiah Blue' with Allium senescens (T1), Festuca glauca 'Eljiah Blue' with Sedum takesimense (T2), Festuca glauca 'Eljiah Blue' with Agastache rugosa(T3), and Festuca glauca 'Eljiah Blue' with Chrysanthemum coreanum (T4) were planted in each experimental plot. Plant height and covering rate were measured to evaluate the growth of Festuca glauca 'Eljiah Blue'. Also, relative growth rate (RGR) of plant height, RGR of plant width, and mortality rate of the flowering ground-cover plants were estimated. Plant height and cover rate of Festuca glauca 'Eljiah Blue' was greatest in T3. RGR of plant height was greater in the order of Agastache rugosa, Allium senescens, Chrysanthemum coreanum, and Sedum takesimense. In particular, RGR of plant width was also greatest for Agastache rugosa. Mortality rates of Agastache rugosa and Allium senescens were lowest at 11%. Therefore, based on good growth of Festuca glauca 'Eljiah Blue' planted with Agastache rugosa, these results were suggested as a desirable combination of plant species for rooftop gardening.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.47 no.4
• /
• pp.269-272
• /
• 2002

This study was carried out to investigate varietal differences on growth characteristics under the conditions of PE film-mulching and non-mulching in sesame. At maturing stage from 76 to 95 days after sowing, Yangbaeckkae, non-branching plant type, under non-mulching showed larger leaf area index (LAI) than that of film-mulching, while plant height and the number of capsules per plant were similar to those of film-mulching. LAI of Ahnsankkae, branching plant type, under non-mulching was similar to film-mulching, while plant height and the number of capsules per plant were smaller than those of film-mulching. Net assimilation rate (NAR) of two varieties under non-mulching was lower at seedling stage from 25 to 35 days after sowing but higher at flowering stage from 45 to 55 days after sowing. At maturing stage from 66 to 77 days after sowing, NAR and crop growth rate (CGR) of Yangbaeckkae under non-mulching were greater than those of film-mulching, whereas those of Ahnsankkae under non-mulching were lesser than those of film-mulching. Yield under non-mulching was decreased by 7 % in Yangbaeckkae and 33 % in Ahnsankkae compared with that of film-mulching, therefore Yangbaeckkae was more adaptable for non-mulching than Ahnsankkae. Main factors decreasing yield of Yangbaeckkae under non-mulching were small LAI, NAR, and CGR at the stage of young seedling, and small number of capsules at early maturing stage from first flowering to 20 days after first flowering.

• Korean Journal of Plant Resources
• /
• v.21 no.1
• /
• pp.47-51
• /
• 2008

This study was carried out to get the basic data for safflower cultivation according to sowing date by growth analysis for 2 years form 2003 to 2004 at Institute of natural product in Uiseong, G.B.A.R.E.S.. Safflower(Cheongsoo cultivar) was seeded at March 1st, April 1st, May 1st, and July 1st in field. The necessary date for germination was 24 days, when safflower was seeded at March 1st, but it was 8 days which sowed at April 1st and when the seed was sowed at high temperature period, the necessary date for germination was getting short. The necessary date for flowering was the same trend as germination; it took 104 days at March 1st, 79 days at April 1st, 65 days at May 1st, and 58 days at July 1st sowing treatment. The safflower growth was the most vigor when it was sowed at March 1st. T/R(Top/Root) ratio was gently increased during growing season, but when the seed was sowed at July 1 st, it was low compare to sowing at March 1st and April 1st. RGR(Relative growth rate) was the highest during shoot growth stage, but it was rapidly decreased after flowering. CGR(Crop growth rate) was increased at branching stage, and the increasing velocity was slightly decreased just before flowering, and it was increased again at flowering and at this stage, CGR was the highest, and then it did not increased. NAR(Net assimilation rate) was the highest at shoot growth stage during growing season, and was the highest which was sowed at March 1st.

• Horticultural Science & Technology
• /
• v.16 no.4
• /
• pp.531-532
• /
• 1998

This study was conducted to investigate the optimum concentration and time of BA treatments for the improvement of flowering in Cymbidium encifolium 'Tekkotsusosin'. The flowering rate was increased by the higher concentration of BA treatment, and reached 100% by $400mg{\cdot}L^{-1}$ treatment. But high concentration induced the flower malformation. Therefore, the optimum concentration of BA for increased of flowering rate was about $300mg{\cdot}L^{-1}$. In the time of BA treatment, plants which were treated in June to August by BA $300mg{\cdot}L^{-1}$ were flowered, especially up to 100% in August. However, those treated in April, May, and September did not.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.4
• /
• pp.325-330
• /
• 2004

This study was carried out to determine adequate planting date, to compare the growth characteristics between early and late maturing cultivars, and to provide the data for the cultivation techniques of soybean [Glycine max (L.) Merr.] in double cropping system with winter crops on paddy field in Korea. Cultivars were planted on 26 May, 16 June, and 7 July with a planting density of $70cm(row\;widtb)\;{\times}\;10cm$ (planting spacing). Seed yield of soybean planted on June 16 and July 7 was approximately $37\%\;and\;53\%$, respectively, less than that of conventional planting date of May 26 in Pungsan-namulkong, and planted on June 16 and July 7 was about $30\%\;and\;37\%$, respectively, less then that of conventional planting date of May 26 in Hanamkong. The number of pods and seeds per plant decreased as planting date delayed. Seed weight increased in Pungsan-namulkong but decreased in Hannamkong as planting date delayed. The flowering date was late in delayed planting plots, but it was shorted for days from emergence to flowering and from emergence to maturity. The plant height of Hannamkong was greater than Pungsan-namulkong from the emergence to flowering stages, but in contrast, it was greater in Pungsan-namulkong than Hannamkong after flowering stage (50d after emergence) when it planted on May 26. There were no significant differences between two soybean cultivars at planting dates of June 16 and July 7. Leaf number, leaf area, and dry matter were also reduced by late planting, and Both of them were shown in high reduction at the later planting. There was a high significant difference at the flowering $(r\;=\;0.87^{**})$ and pod formation $(r\;=\;0.91^{**})$ stages between leaf dry matter and seed yield. Crop growth rate (CGR) was greater at $R2\~R3$ growth stages compared to $R3\~R4\;or\;R4\~R5$ growth stages in two soybean cultivars and the greatest CGR was obtained at planting date of May 26 in two soybean cultivars except for R4-R5 growth stage in Pungsan-namulkong. There was a highly significant positive difference between the seed yield and the leaf area index (LAI) across R3 to R4 and R2 to R3 stages. The photosynthetic rate $(P_N)$ of the uppermost leaf position had no significant difference among planting dates and between two soybean cultivars. However, $P_N$ of the $7^{th}$ leaf position increased as the planting date delayed.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.1
• /
• pp.38-43
• /
• 2010

To develop Korean native lilies as mini-potted plants, the effects of plant growth retardants on inhibiting stem elongation and improving flowering rate were evaluated. Bulblets of Lilium concolor var. parthneion (5-7 g) and L. dauricum (3-4 g fresh wt) derived from in vitro culture and then enlarged by field culture were applied with 0, 25, 50, or $100mg{\cdot}L^{-1}$ ancymidol, diniconazole, and uniconazole through bulb dipping, foliar spray, and drench. In L. concolor var. parthneion, uniconazole dipping most effectively reduced plant height by 60.7-78.3% depending on concentration compared with control without decreasing flowering percentage. In L. dauricum, dipping into diniconazole solution significantly retarded the plant height by 70.0-86.3% and improved flowering percentage by 8.3-18.2% compared to control of 0%. Drench of $25-50mg{\cdot}L^{-1}$ ancymidol was also effective on inhibition of stem elongation and improvement of flowering rate. Therefore, dipping into $50-100mg{\cdot}L^{-1}$ uniconazole solution in L. concolor var. parthneion and dipping into $25mg{\cdot}L^{-1}$ diniconazole solutions or drench of $25mg{\cdot}L^{-1}$ ancymidol in L. dauricum can be useful to produce the mini-potted plants.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.2
• /
• pp.142-146
• /
• 2010

'Arirang', an early-flowering pure white gladiolus with purple core, was released by the National Institute of Horticultural & Herbal Science (NIHHS) in 1998. The selection was derived from the cross between the progenies of the early flowering dark orange 'Arianne' and bright red domestic cultivars 'Hongkwang'. The breeding was conducted in 1993 and finally selected in 1998 after five (5) years (1994 to 1998) of experimentation. 'Arirang' is a cut flower with bright white color petals and purple core which exhibited early flowering and vigor without stem bending. These can be cultivated in areas or regions with strong winds during summer. 'Arirang' has a very firm growth form and sturdy branches which do not bend when planted in the open fields. Likewise, the plant had high tolerance to flooding and resistance hence could grow vigorously in open areas. It is a fast- growing plant which exhibits high corm production rate. 'Arirang' had a 10.5 cm wide flower and 140 cm plant height. During summer, the average number of days to flowering was recorded at 75 days of 'Arirang'. Top dressing must be conducted once or twice during corm production to enhance corm quality and quantity.

• FLOWER RESEARCH JOURNAL
• /
• v.16 no.4
• /
• pp.260-265
• /
• 2008

Studies were carried out to elucidate the effect of temperature, glasshouse forcing date and $GA_3$ on the growth and flowering of pot Hydrangea macrophylla Ser. The plant height was elongated in the $5^{\circ}C$ treatments as 38 cm compared with $20^{\circ}C$ treatment as 6.7 cm, and stem length showed the similar results. The leaf length and width was broadened in the lower temperature, and stem diameter showed the same tendency. The first flowering date in the $15^{\circ}C$ and $20^{\circ}C$ treatment shortened markedly than $5^{\circ}C$ treatment. Days to flowering date of $5^{\circ}C$ was 161 day, while it shortened as 88 day in the $15^{\circ}C$ treatment. The flowering rate was 75.8~90.7% in the temperature. The plant height was elongated in the late glasshouse forcing date, and the leaf length and width showed the similar tendency. The plant height increased in the higher concentration of $GA_3$ compared to the control, and leaf length and width showed the similar results. The first flowering day was advanced by 7 days in the $GA_3$ $50mg{\cdot}L^{-1}$ treatment which had been transferred to greenhouse on Dec. 30 compared with the control of which first flowering day was March 17, and the days to first flowering was conspicuously shortened in the late glasshouse forcing treatment. The width of flower cluster was increased in the $GA_3$ at Dec. 30 glasshouse forcing treatment. The flowering rate was markedly decreased as 62.3% in the control of Nov. 15 treatment, but was increased as 97.9% of $GA_3$ $50mg{\cdot}L^{-1}$ of Jan. 15 treatment.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.28 no.1
• /
• pp.13-18
• /
• 2008

This experiment was conducted to compare the agronomic characteristics, flowering condition and productivity of introduced annual legumes at paddy field of Seonghwan(Cheonan, Chungnam, Korea) from September 2006 to May 2007. Annual legumes used in this study were hairy vetch(Vicia villsa, Rosa), crimson clover(Trifolium incarnatum, Contea), berseem clover(Trifolium alexandrinum, Alexandria), persian clover(Trifolium resupinatum, Prolific), balansa clover(Trifolium michelianum, Paradona), sweet clover(Melilotus officinalis, Yellow) and forage pea(Pisum sativum, Austrian). Emergency rate after seeding were 90% or more in crimson clover, hairy vetch, forage pea and berseem clover. Wintering of hairy vetch and crimson clover were excellent as 98% and 95%, respectively. Flowering rate of harvesting date(May 10) was 100% in crimson clover, 98% in balansa clover, 5% in persian clover and others were not flowering. Fresh and dry matter yield of crimson clover were highest as 72,556 kg/ha and 16,062 kg/ha, respectively. Crude protein yield of hairy vetch was highest as 2,929 kg/ha but not significant with crimson clover(2,169 kg/ha). TDN yield of crimson clover was highest as 9,007 kg/ha but not significant with hairy vetch(7,366 kg/ha). According to the results from this study, it is suggested that crimson clover would be recommendable for autumn-sowing annual legume at paddy field of Central Provinces.