• Journal of Plant Biotechnology
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• v.50
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• pp.190-199
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• 2023

Date palm (Phoenix dactylifera L.: Arecaceae) is a dioecious species where only female trees bear fruits. In their natural state, date palms produce dates once a year. However, in Thailand, some trees were observed to produce dates during the off-season, despite no variations in morphology. The availability of such off-season fruits can significantly increase their market value. Interestingly, most female off-season date palms investigated in this study were obtained through micropropagation. Hence, there is an urgent need for genetic markers to distinguish female offseason flowering plantlets within tissue culture systems. In this study, we aimed to develop random amplification of polymorphic DNA-sequence characterized amplified region (RAPD-SCAR) markers for the identification of female off-season flowering date palms cultivated in Thailand. A total of 160 random decamer primers were employed to screen for specific RAPD markers in off-season flowering male and female populations. Out of these, only one primer, OPN-02, generated distinct genomic DNA patterns in female off-season flowering (FOFdp) individuals compared to female seasonal flowering genotypes. Based on the RAPD-specific sequence, specific SCAR primers denoted as FOFdpF and FOFdpR were developed. These SCAR primers amplified a single 517-bp DNA fragment, predominantly found in off-season flowering populations, with an accuracy rate of 60%. These findings underscore the potential of SCAR marker technology for tracking offseason flowering in date palms. Notably, a BLAST analysis revealed a substantial similarity between the SCAR marker sequence and the transcript variant mRNA from Phoenix dactylifera encoding the SET DOMAIN GROUP 40 protein. In Arabidopsis, this protein is involved in the epigenetic regulation of flowering time. The genetic potential of the off-season flowering traits warrants further elucidation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.115-122
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• 2004

This study was conducted to investigate the effect of the seeding and harvesting dates on the growth characteristics, dry matter yield and quality of com for silage in alpine area(altitude 800m a.s.l.) of National Livestock Research Institute from 2001 to 2002. The experiment was arranged in a split plot design with three replications. Main plots consisted of three seeding dates, 10 May, 20 May and 30 May. Sub plots consisted of harvesting dates, 15 September, 25 September and 5 October. Tassel height of com was decreased with seeding dates, 30 May, 10 May and 20 May in order, and harvesting date of 5 October was apt to be high. Ear height of com was decreased with seeding dates, 20 May, 30 May, and 10 May in order, and harvesting date of 15 September was the lowest of all treatments. Ear rate of com was decreased with late seeding dates, and it was the highest with harvesting date of 5 October. Dry matter yield was decreased with late seeding dates(P<0.05), and it was increased with late harvesting regardless of seeding dates(P<0.05). Crude protein content of com stover was increased with late seeding dates, and that of com ear was the highest with seeding date of 20 May. And crude protein contents of com stover and ear were the highest with harvesting date of 15 September. NDF contents of com stover and ear were the highest with seeding date of 10 May and 20 May, respectively, and NDF content of com stover was the highest with seeding date of 10 May and there was no difference among treatments in NDF content of ear. ADF content of com stover was 42.1 to 42.6% regardless of seeding dates, and that of com ear was the highest with seeding date of 30 May. ADF content of com stover and ear was increased with early harvesting date excepting for harvesting date of 20 May. These results indicate that 20 May and 25 September would be the optimum seeding date and harvesting date, respectively, for dry matter yield and nutritive value of silage com in alpine area.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.80-88
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• 2014

This study was carried out to understand the effect of sowing date on growth characteristics, flower duration of a total of 6 domestic rapeseed cultivars, "Sunmang", "Tammiyuchae", "Tamlayuchae", "Naehanyuchae", "Yongsanyuchae" and "Hallayuchae" with different sowing dates (25 Sept., 5 Oct., 15 Oct., 25 Oct., 5 Nov.) in Muan, Jeollanamdo, Republic of Korea. The results obtained were summarized as the follows: The number of seedling stand after overwintering was decreased in all 6 cultivars. It changed little until 5 Oct., and then showed continuously largely decrease as the sowing date being delayed. As the sowing date was being delayed, plant height was decreased while Silique length and thousand seed weight were increased. Seed yield in all 6 cultivars decreased almost linearly with late sowing date. In correlation analysis between the delaying sowing date and growth characteristics, it was inversely correlated with plant height ($r=-0.769^{**}$), No. of branches/plant ($r=-0.760^{**}$), No. of siliqua/panicle ($r=-0.631^{**}$) and seed yield ($r=-0.946^{**}$), while showed a positive correlation with silique length (r=0.635), seed diameter ($r=0.629^{**}$) and thousand grain weight ($r=0.422^*$). No. of seeds/silique and seed set percentage were not significantly correlated with the delaying sowing date. The flower duration was long in order of Sunmang, Tammiyuchae, Yongsanyuchae, Naehanyuchae, Hallayuchae and Tamlayuchae. Varietal variation of flowering date was larger with early sowing date than with delaying sowing date. The range of flower duration across all cultivars was from 1 day of Tamlayuchae to 14 days of Sunmang according to the sowing date, and the end flowering date was able to be extended from 2 to 9 days, compared to normal date of end flowering.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.3
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• pp.110-119
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• 2017

The agroclimatic indices are produced by statistical analysis based on primary climate data (e.g., temperature, precipitation, and solar irradiance) or driving agronomic models. This study was carried out to evaluate how selection of daily temperature for a climate normal (1983-2012) affected the precision of the agroclimatic indices. As a first step, averaged daily 0600 and 1500 LST temperature for a climate normal were produced by geospatial schemes based on topo-climatology ($365days{\times}1$ set, EST normal year). For comparison, 30 years daily temperature data were generated by applying the same process ($365days{\times}30sets$), and calculated mean of daily temperature (OBS normal year). The flowering date of apple 'Fuji' cultivar, the last frost date, and the risk of late frost were estimated based on EST normal year data and compared with the results from OBS normal year. The results on flowering date showed 2.9 days of error on average. The last frost date was of 11.4 days of error on average, which was relatively large. Additionally, the risk of the late frost was determined by the difference between the flowering and the last frost date. When it was determined based on the temperature of EST normal year, Akyang was classified as a risk area because the results showed that the last frost date would be the same or later than the flowering date in the 12.5% of area. However, the temperature of OBS normal year indicated that the area did not have the risk of a late frost. The results of this study implied that it would be necessary to reduce the error by replacing the EST method with the OBS method in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.440-448
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• 1989

The present experiment was conducted to investigate the effects of seeding date on agronomic characters including seed weight of soybean (Glycine max (L.) Merr.) at Sunchon, the southern coastal area of Korea. One hundred eighteen native and improved varieties were used in this study. As the seeding date was delayed, the number of days to flowering for the cultivars was reduced. This trend was more obvious in late maturing cultivars(LMC) than in early and medium maturing cultivars (EMC and MMC). Late seeding also resulted in decrease in the number of leaves, stem length, and number of nodes. The heaviest seed weight was obtained with EMC and MMC planted on May, and seed weight decreased with delayed seeding date. Seed weight was positively correlated with number of days to flowering, number of total leaves at flowering, stem length and number of nodes on main stem at maturity. Based on seed weight the cultivars was classified into five types: Type I; Seed weight of the cultivars decreases with delayed seeding date. Type II; Seed weight of the cultivars does not vary with seeding date. Tyep III; Seed weight of the cultivars increases with delayed seeding date. Type IV; Seed weight of the cultivars increases when the seeding date approached the appropriate seeding date, but decreases thereafter. Type V; The reversed type IV. Type I, II, III, IV and V occupied 37, 16, 17, 10 and 20％ of the tested cultivars, respectively.

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

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.111-118
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• 2015

The objective of this study was to determine the response of rapeseed (Brassica napus) to different planting date in the spring and varieties on growth and flowering characteristics. Eight rapeseed varieties were sowed at 10 day interval from 1st to 31th of March at Muan and Jeju in Korea. Significant planting dates and rapeseed varieties effects for growth, start of flowering and duration. As the planting date was being delayed, plant length and flower number were decreased, but branch number was increased. And, start of flowering date was retarded and flowering duration decreased with later planting date. Days from planting to flowering was shortened as seeding date was delayed and shortening degree was similar between experimental locations, Muan and Jeju. The days to flowering for rapeseed about 73~94 days for 1st March and then decreased to 57~71 days for the 31th March of planting date. 'Tammiyuchae' and 'Mokpo 111' seeded on each planting date come into blossom more earlier about 10 days as compared to 'Tamlayuchae' and 'Naehanyuchae'. The duration of flowering for the B. napus varieties was shortened as planting date was delayed. The results revealed that flowering characteristics of rapeseed can be greatly enhanced by planting as early as possible, and early flowering varieties i.e. 'Tammiyuchae' and 'Spring' were the most suitable varieties among the tested varieties for planting in the spring.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.427-434
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• 2017

This experiment was conducted to investigate the aspect of tiller occurrence, growth and yield of sorghum according to planting distance and sowing date. The object of this experiment is to get basic data to inhibit non-productive tillers uneconomical and cumbersome for mechanical harvesting. Also another object was to evaluate optimum planting distance and sowing date in central district area. Total number of tillers was more in 80 cm ridge than 60 cm ridge and it was increased as the planting distance was wider from 15 cm to 30 cm on the each ridge. Ratio of effective tillers was higher in 60 cm ridge than 80 cm ridge and it was decreased as planting distance was wider from 15 cm to 30 cm. The lower the planting distance, the more increased total number of tillers, whereas effective tillers was decreased as planting distance was high. Average of total number of tillers of three varieties was higher in sowing date of May 2 (1st sowing date), whereas ratio of effective tillers was the highest in sowing date of May 23 (2nd sowing date). Hwanggeumchal showed the highest total number of tillers (1.2 tillers), while Moktaksusu had the lowest total number of tillers (0.8 tillers) among three varieties. There were no significant difference between planting distance and days to heading and ripening date from seeding. Culm length increased as planting distance was high, but ear length, grains per ear and 1000 grain weight were decreased on the other hand. The highest yield of sorghum per 10a was obtained from $60{\times}20cm$ planting distance among 6 planting distances.

• Journal of Industrial Convergence
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• v.19 no.5
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• pp.21-34
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• 2021

The purpose of this study is to find out what the investment efficiency of BW is from an investor's point of view and to suggest an efficient investment plan to investors. The research method is to investigate the coupon interest rate, maturity interest rate, issuance date, right exercise start and end date, maturity date, exercise price, etc. for BW issued from 2014 to July 2021. By connecting them, it was attempted to quantitatively understand the efficiency of investment in BW and the effect of new stock acquisitions. As a result of the study, the ratio of the number of days in excess of the exercise price was 41.3% of the available days for new stocks, so it was analyzed that the investment efficiency of bonds with warrants was not high. The return on the exercise start date was 24.8% on average and the return on the end date was 52.6% on average, showing a positive return on average, so it was derived in line with investor expectations. The number of stocks with negative returns on the exercise start date was 1.47 times higher than the number of stocks with positive returns, and the number of stocks with negative returns on the end date was 1.16 times higher than the number of positive stocks.

• Analytical Science and Technology
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• v.35 no.6
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• pp.267-273
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• 2022

In this study, a quality evaluation was conducted to change the sell-by date of fish cakes to the use-by date. For product quality evaluation, storage conditions were set at 5, 10, and 15 ℃, and five tests of pH, acid value, volatile basic nitrogen, bacterial count, and coliform group were performed. As a result of the experiment, the quality safety limit period of fish cakes stored at 5 ℃ was 43 days, that of fish cakes stored at 10 ℃ were 30 days, and that of fish cakes stored at 15 ℃ was 7 days. Among the five test items used for quality evaluation, the quality-limit indicators were acid value, number of bacteria, and coliform groups. The index that determined the quality safety-limit period under the three storage conditions was the bacterial count. The sell-by date of the fish cake used in this experiment was 10 days. However, through quality evaluation, the use-by date at 10 ℃ was 28.5 days, which was calculated by multiplying the 30 days; the quality limit period, by a safety factor of 0.95. However, this study conducted a quality study on one item of fish cakes from a single company, and it was difficult to use the quality safety-limit period and use-by date set in this study universally. To change the sell-by date to the use-by date, extensive quality research on various products will be required. If this system is well established, it can help reduce food waste through proper consumption of food, and consumers will be able to consume food with confidence.