• 한국해양학회지
• /
• v.21 no.3
• /
• pp.156-170
• /
• 1986

The phytoplankton ecology of estuarine waters was investigated in the Kyeonggi Bay from May 1981 to September 1982 on monthly basis. In this study area, a total of 228 phytoplankton species was identified. Among these taxa, the most dominant species are diatoms in this area. Tychopelagic plankton occupies 40.4% of total species. The percentage of tychopelagic plankton density ranged from 10.2% in September to 92.7% in March of monthly standing crops. From late autumn to early spring, the percentage values are more than 72%. They play an important role from late autumn to early spring in this estuarine plandton community. These tychopelagic planktons are induced from benthic diatoms. Because the bottom shear stresses generated by the tides and winds are stronger than the adhesive and tractive force of benthic diatoms, most of benthic diatoms must be resuspended into tychopelagic suspensions during autumn and winter. Paralia sulcata is the most important tychopelagic plankton as an indicator species of water mixing in the eastern coastal area of Yellow Sea. This species seems to have even broader tolerance to the environmental stress than Skeletonema costalum, and tends to fill the gaps in winter, when the phytoplandton is relatively unsuccessful. Skeletonema costatum and Chaetoceros debilis are dominant in other seasons. Typical blooms of phytoplankton occur in spring and early autumn, The first bloom is started by Skeletonema costatum in early May, second peak is formed by various diatom population in September.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 1996.11a
• /
• pp.67-72
• /
• 1996

The Purpose of this study is to examine the characteristics of the space composition of Korean traditional residence by analysing the meaning and function of traditional residence's An-Daecheong of late Chosun dynasty, as well as its interrelationship with other spaces. It can be analysed. then that such factors as the weak economic ablility of the current agricultural society and reduction of the number of family member have made the function of the An-Daecheong weak, and that such factors as westernization of life style and modernization of residence facilities have reduced the functional interrelationship of the An-Daecheong. An-Madang and Kitchen.

• YAKHAK HOEJI
• /
• v.38 no.1
• /
• pp.20-23
• /
• 1994

The contents of ginkgolides were determined in the leaves of male and female Ginkgo biloba from late spring until mid-autumn. Ginkgolides were detected during the whole growing season in the leaves of each tree. Ginkgolides content was low in late spring, gradually increased to reach a maximum in august and decreased thereafter. The male trees have two or three times higher ginkgolides content than the female trees. Comparing our results with that of previously reported values, the sexual variation of ginkgolides content seemed not to be genetic.

• Journal of Sericultural and Entomological Science
• /
• v.16 no.2
• /
• pp.1-34
• /
• 1974

These experiments pertain to various factors influencing the quantitative characters of cocoon crops in summer and early autumn seasons. Initially, in order to establish the possible ways of the silkworm rearing more than three times a year in Korea, the author attempted to get further information about the various factors affecting the cocoon crop in every silkworm rearing season. The trials were conducted eleven times a year at four places for three years. The field trial was conducted with 19 typical sericultural farmers who had been surveyed. At the same time the author statistically analyzed the various factors in close relation to tile cocoon crop in autumn season. The effect of guidance on 40 sericultural farmers was analyzed, comparing higher level farmers with lower level farmers ; and the author surveyed 758 non-guided farmers near the guided farmers during both spring and autumn seasons. In addition, another trial on the seasonal change of leaf quality was attempted with artificial diets prepared with leaves grown in each season. It was found that related factors to cocoon crops in summer and early autumn seasons appeared to be leaf quality, and temperature for young and grown larvae. A 2$^4$ factorial experiment was designed in summer season, and another design with one more level of varied temperature or hard leaf added to a 24 factorial experiment was conducted in early autumn. The experimental results can be summarized： 1. Study on the cocoon crops in the different rearing seasons 1) It was shown that earlier brushing of silkworm generally produced the most abundant cocoon crop in spring season, and earlier or later than the conventional brushing season, especially earlier brushing was unfavorable for the abundant cocoon crop in autumn season. 2) The cocoon crop was affected by the rearing season, and decreases in order of sire with spring, autumn, late autumn, summer and early autumn seasons. 3) It was Proved that ordinary rearing and branch rearing were possibles 4 times a year ; in the 1st, 3rd, 8th, and 10th brushing season. But the 11th brushing season was more favorable for the most abundant cocoon crop of branch rearing, instead of the 10th brushing season with ordinary rearing. 2. Study on the main factors affecting the cocoon crop in autumn season 1) Accumulated pathogens were a lethal factor leading to a bad cocoon crop through neglect of disinfection of rearing room and instruments. 2) Additional factors leading to a poor cocoon crop were unfavorable for rearing temperature and humidity, dense population, poor choice of moderately ripened leaf, and poor feeding techniques. However, it seemed that there was no relationship between the cocoon crop and management of farm. 3) The percentage of cocoon shell seemed to be mostly affected by leaf quality, and secondarily affected by the accumulation of pathogens. 3. Study on the effect of guidance on rearing techniques 1) The guided farms produced an average yearly yield of 29.0kg of cocoons, which varied from 32.3kg to 25.817g of cocoon yield per box in spring versus autumn, respectively. Those figures indicated an annual average increase of 26% of cocoon yield over yields of non-guided farmers. An increase of 20% of cocoon yield in spring and 35% of cocoon yield in autumn were responsible. 2) On guided farms 77.1 and 83.7% of total cocoon yields in the spring and autumn seasons, respectively, exceeded 3rd grade. This amounted to increases of 14.1 and 11.3% in cocoon yield and quality over those of non-guided farms. 3) The average annual cocoon yield on guided farms was 28.9kg per box, based on a range of 31.2kg to 26.9kg per box in spring and autumn seasons, respectively. This represented an 8% increase in cocoon yield on farms one year after guidance, as opposed to non-guided farms. This yield increase was due to 3 and 16% cocoon yield increases in spring and autumn crops. 4) Guidance had no effect on higher level farms, but was responsible for 19% of the increases in production on lower level farms. 4. Study on the seasonal change of leaf quality 1) In tests with grown larvae, leaves of tile spring crop incorporated in artificial diets produced the best cocoon crop; followed by leaves of the late autumn, summer, autumn, and early autumn crops. 2) The cocoon crop for young larvae as well as for grown larvae varied with the season of leaf used. 5. Study on factors affecting the cocoon crops in summer and early autumn A. Early autumn season 1) Survival rate and cocoon yield were significantly decreased at high rearing temperatures for young larvae 2) Survival rate, cocoon yield, and cocoon quality were adversely affected by high rearing temperatures for grown larvae. Therefore increases of cocoon quantity and improvement of cocoon quality are dependent on maintaining optimum temperatures. 3) Decreases in individual cocoon weight and longer larval periods resulted with feeding of soft leaf and hard leaf to young larvae, but the survival rate, cocoon yield and weight of cocoon shell were not influenced. 4) Cocoon yield and cocoon quality were influenced by feeding of hard leaf to grown larvae, but survival rate was not influenced by the feeding of soft leaf and hard leaf. 5) When grown larvae were inevitably raised at varied temperatures, application of varied temperature in the raising of both young and grown larvae was desirable. Further research concerning this matter must be considered. B. Summer season 1) Cocoon yield and single cocoon weight were decreased at high temperatures for young larvae and survival rate was also affected. 2) Cocoon yield, survival rate. and cocoon quality were considerably decreased at high rearing temperatures for grown larval stages.

• Korean journal of applied entomology
• /
• v.46 no.3
• /
• pp.425-430
• /
• 2007

Occurrence of Liriomyza trifolii and its biological control efficacy using Neochrysocharis formosa were evaluated in two eggplant cropping systems of spring and autumn cultivation. L. trifolii adults began to be attracted on a yellow sticky traps from late April and they increased from early June. A high density of L. trifolii adults was maintained from middle June to middle July. The releases of two N. formosa per plant with 3 times as weekly intervals from May 25, 2004 for spring culture resulted control effect of 90.1% in parasitism to L. trifolii in late July. The releases of two N. formosa per plant with 4 times as weekly intervals from August 31, 2004 for autumn culture resulted control effect of 81.3% in population of L. trifolii with 64.4-69.9% in parasitism.

• Journal of the Korean Geographical Society
• /
• v.52 no.1
• /
• pp.1-13
• /
• 2017

This study aims to identify the warm and cold periods(WP, CP) of November appeared in the daily normals of daily minimum temperature of Seoul for 1941~1970 and 1971~2000 and to investigate synoptic characteristics of the temperature changes of WP and CP. The WP temperatures are increased clearly(p value 0.000), the CP temperatures are also warming but not significant statistically. In WP, there are not apparent trends corresponding the warming of WP temperature, in the Siberian High, Sea Level Pressure(SLP), 925hPa surface wind(U925, V925) around the Korean peninsula. In high period(1972~1979) of WP temperature, there are positive SLP anomaly and anomalous anticyclonic circulation pattern of 925hPa wind field over the Korean peninsula then the winter monsoon is weakened and the WP temperature is ascending. In CP, the Siberian high are weakening, the Hokkaido eastern low are strengthening and the westerlies(U925) over the Korean Peninsula are enlarging. So CP temperature are suppressed in rising trend or shows weak descent.

• Korean Journal of Agricultural Science
• /
• v.46 no.3
• /
• pp.439-449
• /
• 2019

The purpose of this research was to evaluate the effects of different sowing dates on growth characteristics, seed productivity and feed value of triticale in Gyeongbuk province. The experiment was conducted from September 2015 to July 2017, using triticale "Joseong" cultivar of 150 kg of seed/ha and sown at 10 days intervals from different sowing dates ($30^{th}$ September, $10^{th}$, $20^{th}$ and $30^{th}$ October) in 2015 and 2016, respectively. The emergence date in the autumn season was 8 - 18 days after sowing in 2015 and 2016. The heading, flowering and maturing periods were the fastest on $30^{th}$ September compared to the other sowing dates. The average number of stem and panicle per unit area were 409.3 - 428.5 and 330.9 - 334.0 on $30^{th}$ September and $10^{th}$ October, which were higher than those sown on $20^{th}$ and $30^{th}$ October, 2015 and 2016, respectively (p < 0.05), and the average number of grain and kernel weight was 47.1 - 48.1 and 2.2 - 2.3 g on $30^{th}$ September and $10^{th}$ October, which were higher than the late sowing dates. In case of seed yield as affected by different sowing dates, the highest yield was found on the sowing plot of late September and $10^{th}$ October, which were 5,680 and 5,918 kg/ha, respectively (p < 0.05). However, the average CP content was 10.7%, CF content was 2.8% and TDN content was 85.3. In conclusion, $30^{th}$ September and $10^{th}$ October were the appropriate sowing dates for a forage self-sufficiency system in Gyeongbuk.

• The Korean Journal of Pesticide Science
• /
• v.4 no.2
• /
• pp.50-55
• /
• 2000

Occurrence, Injury aspects and control effect of some chemicals were investigated on tomato in plastic house from 1997 to 1998. Adults trapped by yellow sticky trap and sweeping net were increased from late May abruptly. Survey of population densities by yellow sticky trap was more clear than sweeping net. Damaged leaves were found out all the year round in continuous cropping fields and rate of damaged leaves was below 20% in early April and increased gradually up to 80% level after late May. Otherwise, damaged leaves were appeared from 6 weeks after transplanting in first growing field and then damaged leaves was 80% level in spring culture. In autumn culture, rate of damaged leaves was maintained 80% level from transplanting to harvesting date regardless of cultivation years. Number of adults was trapped from late May and peak was late June but mature larva was $6{\sim}8$ individuals in spring culture. In autumn culture, adult and larval densities was maintained high for 3 weeks after transplanting but begun to decrease from 4 weeks(early September). Chlorfenapyr EC, cyromazine WP and abamectin EC could suppress larval populations of Liriomyza trifolii effectively.

• Journal of Bio-Environment Control
• /
• v.16 no.2
• /
• pp.146-150
• /
• 2007

For autumn cutting of Sedum sarmentosum, the influences of bedsoil and cutting date were investigated. Among six kinds of bedsoils mixed upland soil, carbonized rice and sand, the mixture with upland soil and sand (1:1 and 2:1, v/v) showed excellent root and shoot growth. The mixtures with upland soil and carbonized rice were lower rooting than the mixture with upland soil and sand. In field condition, autumn cutting was conducted with $10{\times}5cm$ space using the mixture with upland soil and sand (2:1, v/v) at intervals of 10 days from September 1 to October 10. Both root and shoot growth were significantly decreased by delayed date. In cutting from early to middle September, root and shoot growth, and number of rosette before wintering were desirable for shoot production next spring. The safety date to autumn cutting before wintering was on September 20 in field condition. If autumn cutting is late than September 20, the number of scion has increased 25-30% to secure a full rosette before wintering. The results could provide the beneficial information for cutting propagation of S. sarmentosum under field condition in autumn.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.12 no.2
• /
• pp.81-86
• /
• 2006

Of all factors that govern productivity in sericulture, the role of silkworm egg is of prime importance. The production of silkworm seed involves a long chain of interdependent and highly specialized conditions. Female moths of Bombyx mori L. commence egg deposition immediately when the moths were decoupled. More than 60% of eggs are deposited within 4 hrs after decoupling i.e. 62.33% in CSR-3, 61.67% in CSR-6, 62.50% in CSR-16 and 63.28% in CSR-17. Almost 90% of eggs were laid in the first 12 hrs (93.13% in CSR-3, 90.81% in CSR-6, 89.71% in CSR-16 and 93.17% eggs in CSR-17) after decoupling. Almost 8 to 10% of more eggs were laid when oviposition period was prolonged upto 48 hrs instead of 24 hrs. The present investigation showed that a significant increase of 45 (8.34%), 50 (9.98%), 41 (8.26%) and 45 (8.30%) (P < 0.01) numbers of more eggs were found between 24 to 48 hrs (T6 to T9) in CSR-3, CSR-6, CSR-16 and CSR-17 races respectively. The findings of present investigation is very important for sericulture industry while producing layings to keep for different hibernation schedule especially for autumn/late autumn crop, female may be allowed for prolonged oviposition to get 8 -10% more eggs and farmer may fetch 8 -10 kg. more cocoon yield/l00 dfls with more income.