• The Journal of Natural Sciences
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• v.8 no.1
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• pp.71-80
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• 1995

This experiment was conducted to investigate the effect of raising seedling methods of cold water, low night temperature, and abandoned mine on forcing culture of strawberry. The results were as follows ;1. $17^{\circ}C$ cold water alone and cold water plus 8-hour short day treatments significantly accelerated the flower bud differentiation of Nyoho cultivar to 11 and 15 days, respectively, comparing to common soil raising seedling.2. The date of flower bud differentiation of Nyoho cultivar as influenced by cold water treatment the 17th, the 13th and the 10th of September, respectively, when the seedlings were treated on the 10th of September and on the 25th and the 10th of August in 1991. In 1992, data showed that the flower bud differentiation dates were the 4th and the 2nd of September and the 29th of August when cold water treatment was done on the 10th of August and on the 25th and the 10th of July.3. The first harvest date when Nyoho cultivar was treated by cold water for 30days from Jul. 25 was Nov. 10, this implying that the harvesting day could advanced to 19 days comparing to that by the common soil raising seedling method. The resulting yield was recorded to 21.94 ton per hectare.4. Regardless of the starting date of the treatment, $13^{\circ}C$ low night temperature plus 8-plus short day treatments for 20 days required 17 days to differentiate the flower bud of Nyoho cultivar. Harvesting day could be advanced to 59 days comparing to that by the common raising seedling method when the seedling was treated on July 25, this resulting in increasing the total yield obtained by April 14 of following year to 8.25 ton per hectare.5. When the seedlings of both Nyoho and Hokowase cultivars were raised under the condition of abandoned mine, flowering and harvest date were earlier by the treatment for 20 days than that for 30 days or 40 days. The highest yiesd obtained was recorded in Nyoho cultivar or 1.88 ton per hectare.

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.244-251
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• 2018

The present study aimed to identify the influence of climate change on mating songs of Cicadidae in a phenological perspective. The research sites were located in the central part of the Korean peninsula in which phenological observations by the Meteorological Office are made. The material provided by the Meteorological Office was used for long term phenological analysis. The findings demonstrated, First, the phenological monitoring of cicada is an effective index to detect ecological changes due to climate change, thus indicating the importance of long term phenological investigations for future studies. Second, the analysis on the phenological changes of H. fuscata presented a trend in which the first songs were made at increasingly earlier and later dates, respectively. The phenological data on H. fuscata and average temperatures exhibited a significant negative correlation between the initial mating song period and the average temperatures of June. Furthermore, there was also a significant negative correlation for precipitation in October with the end time and total duration of H. fuscata song. Third, in the regression analysis of the start of H. fuscata song and meteorological factors in Seoul, increasing average air temperature in spring (March to June), which includes June, was associated with an earlier start time of H. fuscata song, with calling starting approximately 3.0-4.5 days earlier per $1^{\circ}C$ increase. Fourth, in the regression analysis of the end of H. fuscata song and meteorological factors in Seoul, increased mean precipitation in October was associated with an early end time and an overall reduction in the length of the song period. The end time of song decreased by approximately 0.78 days per 1mm increase in precipitation, and the total length of the song period decreased by 0.8 days/1mm. This research is important, as it is the initial research to identify the phenological changes in H. fuscata due to climate change.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.382-388
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• 2014

The objective of this study was to determine the risk factors associated with pregnancy following 3 synchronization protocols in dairy cows. Data were collected on 1,952 cows from 22 dairy farms, including synchronization protocols ($PGF_{2{\alpha}}$ + estradiol benzoate [PG+EB], Ovsynch, and CIDR-ovsynch), cow parity, body condition score (BCS), and dates of previous calving, insemination and conception. The odds ratio (OR) for pregnancy were analyzed by logistic regression using the LOGISTIC procedure in SAS. The analysis revealed that farm (p = 0.005), cow parity (p = 0.0001), BCS (p < 0.005), and AI season (p < 0.05) significantly affected and calving to AI interval tended to affect (p < 0.1) the probability for pregnancy. Although synchronization protocols did not affect the probability for pregnancy (p > 0.05), cow parity and synchronization protocols showed a significant interaction (p < 0.005); the OR (0.60) was significantly lower (p < 0.0001) for multiparous cows compared to primiparous cows using PG+EB, whereas the OR (1.44) tended to be higher (p < 0.1) for multiparous cows compared to primiparous cows using the Ovsynch, and the probability for pregnancy did not differ between multiparous and primiparous cows using the CIDR-ovsynch (p > 0.05). Cows with BCS ${\geq}$ 3.00 were more likely pregnant (OR: 1.41) compared with cows having BCS ${\leq}$ 2.75, whereas cows inseminated during summer had a lower OR (0.73) compared with those inseminated during spring. Cows with a calving to AI interval > 150 days were more likely to be pregnant (OR: 1.20) compared with cows with a calving to AI interval ${\leq}$ 150 days. In conclusion, the OR for pregnancy following synchronization protocols in dairy cows was affected by farm, parity, BCS, calving to AI interval of the cow, and AI season, and there was a significant interaction between cow parity and synchronization protocols; the OR for pregnancy was lower for multiparous cows compared with primiparous cows using the PG+EB protocol.

• Korean Journal of Medicinal Crop Science
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• v.3 no.1
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• pp.1-4
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• 1995

To determine the optimum sowing time and nursery period in Perilla frutescens in the southern areas of Korea, perilla frutescens cv. red Perilla local cultivar was grown under three different sowing dates and nursery periods. The blooming period of the area which was sown on the seedbed in Apr.10 and carried out the growing seedling in 30days is Aug. 12 and it is two days earlier than that of the area, Aug.14, sown on the seedbed in Apr. 20 and carried out the growing seedling in 30days of the same month and it is also six days earlier than that of the area, Aug.18, sown on the seedbed in April 30 and conducted the growing seedling in the same date. The stem lengths are 135cm,131cm and 125cm respectively and the number of branches are 26.4, 25.3 and 23.6 respectively. The fresh weight of stem and leaf at the area sown on the seedbed in Apr.10 and conducted the growing seedling in 30days with the width of leaf over 5cm in the middle of Aug. and at the beginning of Sep. is 2,476kg/10a and it shows more increase of 172kg than that of fresh weight of stem and leaf with 2,304kg/10a which was sown on the seedbed in Apr.20 and earned out the growing seedling in 30days, and it also shows more increase of 411kg than that of fresh weight of stem and leaf with 2,065kg/10a at the area sown on the seedbed in April 30 and con­ducted the growing seedling in the same date, The fresh weight of seeds are 609.5kg/10a,509.3kg/10a and 463.2kg/10a respectively and $100.2{\sim}146.3kg$ is more increased. Therefore, the seedling period of the proper seedbed for high yield bumper crop of perilla frutescens for exporting to Japan is April 10 and the number of days for seedling is 30 days.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.1
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• pp.72-80
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• 1999

The study was conducted to establish the safe cropping season for direct- seeding on flooded paddy by the analysis of meteorological data(l973~1992, 20 years) from Korea Meteorological Administration. The critical date for early seeding(CDES) at direct- seeding culture on flooded paddy was decided by the appearance date of daily mean air temperature(DMAT) of 15$^{\circ}C$. The optimum heading date(OHD) was the first day when 22$^{\circ}C$ of daily mean air temperature could be kept for 40 days of ripening period after heading, and the critical date of late heading for safe ripening(CDHR) was the last day when 19$^{\circ}C$ of daily mean air temperature could be kept for 40 days after heading. The optimum seeding date(OSD) and the critical date for late seeding(CDLS) could be decided by the accumulated temperature from OHD and CDHR to the appearance dates of necessary temperatures for early, intermediate, and intermediately late maturing varieties. This results can be used for the determination of the safe cropping season of direct-seeding on flooded paddy in each agroclimatic zone. For instance, the OSD appearance date for early maturing variety in Suwon region appeared to be May 11~20 and the CDLS appearance date was May 31~June 7.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1653-1659
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• 2015

This study compared physicochemical properties and antioxidant activities according to different harvest times in five varieties of black rice (BR). Five cultivars of BR, Nunkeunheukchal (NKHC), Sinnongheugchal (SNHC), Sintoheugmi (STHM), Josaengheugchal (JSHC), and Heugjinju (HJJ), were selected for the study. Cultivars were transplanted on June 20th and cultivated by the Department of Southern Area Crop Science, NICS in Miryang, Korea. Heading dates of NKHC, SNHC, STHM, JSHC, and HJJ were Aug. 17th, Aug. 30th, Sep. 1st, Aug. 20th, and Aug. 12th, respectively. The five different harvest times were as follows; 35, 40, 45, 50, and 55 days after heading date. The highest level of anthocyanin was 35 days after heading date in all varieties. Levels of anthocyanin in NKHC, SNHC, STHM, JSHC, and HJJ were 164, 203, 251, 67, and 210 mg/100 g, respectively. Content of anthocyanin significantly decreased 35 days after heading in four varieties, excluding JSHC. Highest DPPH $IC_{50}$ values were 57, 29, 10, and $27{\mu}g/mL$ in NKHC, SN HC, STHM, and JSHC extracts, respectively. Highest ABTS $IC_{50}$ values were 24, 13, 9, and $11{\mu}g/mL$ in NKHC, SNHC, STHM, and JSHC extracts, respectively. The antioxidant activities were highest 35 days after the heading date and significantly decreased in four varieties, excluding HJJ. The antioxidant activity of HJJ showed no significant difference, according to harvest time. This study suggests that the content of anthocyanin and antioxidant activity could be considered as factors affecting optimal harvest period to produce highly qualified black rice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1307-1313
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• 2007

In order to evaluate the utilization of immature green wheat kernels as food processing material, these experiments were carried out to analyze general composition, free sugars, free amino acids, mineral content and color of 3 wheat varieties according to their heading dates. Contents such as moisture, crude protein, crude lipid and ash were gradually decreased according to the days after heading of 3 wheat varieties, while crude fiber and starch were gradually increased. Maltose and maltotriose contents in immature green wheat kernels were high but its rapidity decreased by closing to ripeness. Contents of free amino acids showed a tendency to decrease, among which alanine content was the highest around 25 days after heading, and then glutamic acid, GABA, glycine in order. Contents of total free amino acid were decreased by closing to ripeness. Among 3 wheat varieties, its contents of Guru wheat was the highest. As wheat matured, ${\beta}-glucan$ contents were decreased from 1.5% to 0.28% on 43 days after heading. Mineral contents of 3 wheat varieties were generally increased by closing to ripeness after coming into ears, and K, Mg were especially prominent. As wheat matured, lightness was decreased, while redness and yellowness were increased. Considering chemical composition and color, the immature green wheat were produced through blanching the spikes harvested before the yellow ripe stage. The harvested green wheat cereals is able to eat raw wheat or cook it as food processing material.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.1-15
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• 1987

This experiment was conducted to investigate the effect of nitrogen top-dressing and Jangyeopkong was planted under two different seeding time (single cropping-May 15, after barley cropping-June 18), four levels of nitrogen top-dressing (0, 3, 6, 9 kg/10a) and two times of nitrogen top-dressing (Hilling time, Flowering Time). The results obtained are summarized as follow: 1. The days to flowering and maturity were delayed a day longer in hilling times than flowering times of nitrogen top-dressing. 2. The number of nodes of main stem and length of internodes didn't show significance among treatments. But, the number of nodes of branches was much higher when the soybean was planted on May 15, and were higher hilling time than flowering time as the amount of nitrogen top-dressing increased. Especially, the number of nodes of branches was high when 6kg of nitrogen was applied during hilling time. 3. The fresh and dry weight of stem and leaves at 10, 25 and 40 days after flowering were increased by increasing the amount of nitrogen top-dressing. More apparent effect of nitrogen was attained high significant when nitrogen was applied at the time of hilling rather than flowering time. 4. The number and fresh weight of nodule, and dry weight were apparently decreased after barley and were decreased according to the increasing the amount of nitrogen top dressing. The degrees of decreasing was more apparent in the hilling time than in the flowering time. 5. The number of pods per plant, and number and weight of grain per plant were higher when the soybean was planted on May 15, the amount of top dressing increased and hilling time rather than flowering time. Especially, yield component were highest when 6kg of nitrogen was applied during hilling time. Also, the grain yield per 10a showed high significance among treatment, and were high when 6kg of nitrogen was applied during hilling time.

• Korean journal of applied entomology
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• v.24 no.3 s.64
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• pp.151-156
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• 1985

Apple leaf miner(ALM), Phyllonorycter ringoniella(Matsumura), occurs $4{\sim}5$ generations a year in Suweon; adult emergence peaks being in mid April, early June, early July, mid August, and mid September with the highest one in the 4th generation. Numbers of days required to complete the development(egg to adult emergence) were different with oviposited dates; 43days for late May, $32{\sim}37$ days for June to July, and 39days for early August. ALM larvae oviposited after late August did not emerge and went into diapause. Sites of the infested leaf on the shoot seemed to be somewhat different with the ALM generations; the preferred leaf sites being the 1st-6th leaf for the 1st, the 4th-9th for the 2nd, the 4th-18th for the 3rd or 4th, and the terminal leaves of the first growth shoot or the leaves of the secondary shoot for the 5th generation. Parasites of three families emerged from the mines of ALM in Suweon. The encyrtid (Holcothorax testaceipes Ratzelburg) occurs 4 generations and the eulophids 5 generations a year. A small number of the braconid(Apanteles sp.) occcrred only in September.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.245-252
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• 2018

Yam bean (Pachyrhizus erosus) is a subtropical plant belonging to the Fabaceae family, and is a tuberous vegetable used as various food material with a crisp and juicy taste. This study was conducted to seek optimum sowing time of yam bean in Korea. For this, we surveyed germination properties by the different temperatures and compared the accumulation temperature (AT) and dry matter production (DMP) on growth stages of yam bean by the different sowing times. Two types of varieties cultivated mainly in Korea, Thailand local variety (TLV) and Cheongunmanma cultivar (CGMM), was used. The germination rate of yam bean was 86.0~94.0% at above $18^{\circ}C$, and germination days was longer at lower temperature. The times for flowering and tuber formation of CGMM were later than those of TLV, and the AT required for flowering, tuber formation and hypertrophy of CGMM were higher than those of TLV by $293^{\circ}C$, $280^{\circ}C$ and $108^{\circ}C$, respectively. Also, DMP of shoot and tuber in CGMM were greater than those in TLV. In sowing at April 25, tuber formation was slower than sowing after that time, and harvest index (HI) was relatively low due to delayed formation and hypertrophy of tuber. In sowing after June 9, DMP of shoot was relatively greater in early growth, but tuber was not sufficient to enlarge due to lack of growth days by cold and frost in late October. In sowing May 10 and 25, DMP of tuber and HI were the highest, because the change of day length and temperature gave an advantage to vegetable growth and tuber development. All above suggest that it was suitable to sow seeds on May for increment of tuber productivity in Korea.