• Korean journal of applied entomology
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• v.41 no.4
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• pp.239-245
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• 2002

It was investigated whether or not such helpers as worker bee, bee-cocoon and egg-cup etc, have any effects on oviposition and colony foundation of the bumblebee queen, Bombus ignitus. Among the helpers tested, the callow workers of B. ignitus and B. terrestris showed the most remarkable effects on the oviposition rates to 92% and 88%, respectively. The live cocoon as a helper improved oviposition rate over 60%. A narcotized old worker 10-20 days-aged after emergence, showed similar effects to a callow worker on the colony development such as oviposition rate, colony foundation and progeny-queen production. On the other hand, dried cocoon, callow honeybee worker or egg-cup did not show a positive effect as a helper. In the number of workers recruited to a foundation queen, two workers showed better effect than one worker on the colony development, with no difference between two and more.

• Korean Journal of Plant Resources
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• v.19 no.6
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• pp.680-686
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• 2006

This experiment was conducted on wild vegetables; Gondalbi (Cirsium setidens), Deoduck (Codonopsis lanceolata Trautv.), and Jandae (Adenophora triphylla var. Joponica Hara) seed to study whether priming with deep sea water results in enhancement of seed germination and identify the optimum concentration of the priming solution, and duration of priming. Seeds were primed with 5 various concentrations (5%, 10%, 15%, 20% and 30%) of deep sea water (DSW) in 12 hours, 24 hours, and 48 hours at $24^{\circ}C$. Since Jandae had seed dormancy, it was kept for four weeks in refrigerator at $2^{\circ}C$ after priming treatment. In Deoduck, 5 percentage DSW priming significantly improved the early germination percentage, radicle length, and plumule emergence percentage. Among the priming period of treatments, 24 hours priming showed better performance in this treatment whereas, in Jandae, 12 hours priming with 10 percentages DSW significantly improved the germination percentage and germination rate. This treatment had increased the final germination percentage by 54%, 15% and 40% compared with control, plain water and $KNO_3$ priming respectively. But in Gondalbi, priming did not improve the germination of seed. However, among the priming treatments, 12 hours priming with 3% $KNO_3$ and 20% DSW gave better performance. In both the wild vegetables; Deoduck and Jandae, priming in deep sea water had improved the germination percentage and germination rate as compare to plain water, $KNO_3$, and without priming treatment. Hence the best seed priming treatment on Deoduck and Jandae are 24 hours with 5% DSW and 12 hours with 10% DSW respectively.

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.228-232
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• 1994

The influence of temperature, soil depth, burial duration, and soil moisture on the germination and viability of Galium spurium L. was studied in field and laboratory. Germination and maturing date were Oct. 20 and May 30, respectively. 1000 seed weight was 1.478g and seed color was dark brown. Optimum storage temperature to break dormancy was that $5^{\circ}C$, and germination rate of $10^{\circ}C$ was 81%, seed was not germinated at $20^{\circ}C$ or greater than $20^{\circ}C$. Optimum burial depth was 2cm and emergence rate was 40%. As bural duration in upland was longer, germination rate was increased, but buried seed of paddy land was died in a month. Optimum soil moisture content for germination was 25.3% in sand loam soil however seeds were not germinated above 43.6% or below 2.1%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.375-382
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• 2021

For stable cultivation in double cropping, it is important to use potato (Solanum tuberosum L.) cultivars with a short dormancy period of 50-70 days and plant seed tubers of appropriate type and size. An experiment was conducted during 2018-2019 to investigate the effects of seed tuber type and size on growth and yield performance in double cropping. Whole tubers of three sizes (10-20 g, 30-40 g, and 50-60 g) and conventional cut tubers weighing 30-40 g from three cultivars with different dormancy periods, namely 'Daeji' (40-60 days), 'Eunsun' (50-60 days), and 'Saebong' (50-80 days), were planted, and their field performance was compared. Regardless of the cultivar, the increase in the whole tuber weight up to 30-40 g led to fast emergence, thereby increasing ground cover rate, shoot growth rate, and tuber growth rate, which ultimately improved tuber yield by 33-54%. Comparing the whole and cut tubers, 'Daeji' and 'Eunsun' showed similar growth and yield performance; as such, the performance of whole tubers weighing 10-20 g was comparable to that of cut tubers weighing 30-40 g. However, 'Saebong', a cultivar with relatively long dormancy period, performed better with cut tuber than with whole tubers. Based on these results, we recommend the use of whole tubers weighing over 30 g for double cropping. Further studies to break tuber dormancy are warranted in cultivars with relatively long dormancy periods (50-80 days), such as 'Saebong'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.1
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• pp.65-69
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• 1991

In order for investigating the factors related to decrease of seedling vigor in the naked barley lines, two naked lines and a covered variety were sprouted with 20 mm rainfall in the natural condition, dried and the sprouted seeds were threshed by hand and small machine thresher, Chiyota. In the case of hand-threshing of the sprouted seeds, the germination rate index (GRI), germination rate, and TTC test value of the different varieties were not different due to the different sprouting degrees, but emergence rate index (ERI) became decreased with stronger sprouting damage. In comparison with hand-threshing, the embryos of sprouted seeds from machine threshing with 700 rpm were partially damaged, and the traits related to seedling vigor were decreased highly significantly. However, the diastatic activity was sharply increased by stronger sprouting and machine threshing. The sprouting degree in the hand-threshing plot was significantly correlated with the diastatic activity(r=0.931＊＊, 0.951＊＊) and GRI(r=0.461), respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.514-520
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• 1996

To clarify the proper nitrogen application level for rasing rice infant seedling under different nursery soil, Dongjinbyeo was raised at seedling box with different basal nitrogen level. The results are as follows. The higher the nitrogen level was, the lower emergence rate and the lower establishment rate. The establishment rate was less than 90%, when the nitrogen was more than 2g/box in hill soil and more than 1g/box in paddy soil. The more the nitrogen level was, the higher the seedling height in hill soil, but was higher in the order of N-2, 3, 1 and 0g /box. Leaf number wasn't significantly different between nusery soils and among nitrogen levels when seedling was raised more than 6 days. The endosperm survival rate was decreased as the increased nitrogen level, but wasn't different between the nursery soils. Amount of root was decreased as the increased nitrogen level in paddy soil, but was heavier in the order of N-1, 0, 2 and 3g /box in hill soil. Mat formation was better as the nitrogen level was decreased in all nursery soils. Considering the emergence rate, seedling charactors and mat formation, the proper nitrogen levels seemed to be 2g /box for hill soil and 1g /box for paddy soil.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.115-126
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• 1990

This study was performed to find differences in phototaxis response of the larva, adult emergence, sex ratio and gall formation rate of Thecodiplosis japonensis Uchida et Inouye between two areas, north and south. Larvae from these two areas, Hweng-sung in north and Moo-an in south, both considered to be the sities of severe outbreak of the insect recently, were collected from the floor and transported to the entomology larboratory, Won-Kwang University in Iri, then overwintered. These larvae were used for various experimental purposes on various dates. The following results were obtained. 1. The sizes of larvae reached 2.45 in length, 0.70 in width for north, and 2.50 in length, 0.72 in width for sourth. It seems that the differents were not significant. 2. It is known that Leaving gall of larvae to the ground for the hibernation usually occurs on rainy days. For the larvae dispersion, the phototaxis response of the larvae was hypothesized. To check this, the author manipulated some different illumination intensities adjusting the distance between the glass tube in which 100 larvae were contained and electric bulb. The glass tubes were blackened all but except a small portion. The phototaxis responses between two areas seemed to be different particularly at low light intensities, 45, 145 and 1000 lux, The larvae from north assembled to the clear portion of the glass tube were more than 30 out of 100, however less than 30 in south sample regardless of the time passage. In either cases, the saturation points came after about 8 to 10 hours. If temperature units were used, the phototaxis curve= after 1 hour illumination between two areas provided significant differences. 3. The adult emergence of south area was lagged 10 days later than that of north area. The accumulated effective day-degrees of temperature for adult emergence were $934^{\circ}C$ for north area and $1180^{\circ}C$ for south area. The emerging duration of north area appeared to be in late May through the early of July and the peak emergence occurred in middle June that was approximately 15days earlier than that of south area. The sex ratio of female to male, regardless of area, was approximately 3 : 1. 4. The rates of gall formation of the red pine(Pinus densiflora Siebold et Zuccarini), 6-year-old seedlings, were as low as 9.94% for north area and 8.87% for south area. Through the close observation, the author presumed that the population reduction was greatly affected during the prepupa stage by relative moisture content and predators, such as spiders and ants presented on the ground.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.125-135
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• 1994

Field experiment was carried out in order to clarify effects of plastic film mulching on temperature and moisture of rhizosphere soil and their subsequent effects on seedling emergence, earlier growth, vegetative growth and grain yield of sesame. The textural class of the experimental field soil was the sandy loam(Bonyang series) and the variety of sesame planted was "Ansan-ggae". The experiment was conducted by combining four sowing dates of April 25, May 10, May 25, June 10 and two mulching treatments(mulching, non-mulching) over two year of 1991 and 1992. The results were summarized as follows : 1. The daily mean soil temperature of 5cm deep soil was increased by 1.4 to $2.8^{\circ}C$ by plastic film mulching. The average soil water content was increased by 0.5 to 3.0%(V/V) in the drier season, while decreased by 1.0 to 2.0%(V/V) in the rainy season by mulching. 2. The establishment rate of sesame seedling was very sensitive to soil temperature. For normal seedling emergence, from the seeding date to the 7th date after sowing, the daily mean soil temperature higher than $21.0^{\circ}C$ was required at the experimental field conditions. 3. The average soil water content in the range of 14.0 to 21.0%(V/V) at 5cm deep soil seemed not to be limiting for the germination and emergence of sesame. The effect of soil water content on seedling establishment was very small in this range, but the optimum level of soil water content ranged from 14.0 to 15.0%(V/V) in the experimented sandy loam. 4. The wetter the soil profile was, the larger the gap of soil temperature between the mulched and non-mulched condition was. The effect of mulching on the establishment rate of sesame seedlings was much greater in the lower air temperature conditions. However, when the sowing of sesame came earlier than at the date with the daily mean air temperature below $19.0^{\circ}C$, the effects of earlier sowing and mulching were offsetted by the retarded seedling growth due to the low air temperature, and thus earlier sowing with mulching did not enhance the grain yield of sesame.

• Korean Journal of Organic Agriculture
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• v.29 no.2
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• pp.223-240
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• 2021

This study was carried out to investigate the economic value of organic wheat production using gelatin·chitin microorganisms in Gwangsan-gu, Gwangju city. The soil condition of experiment field was clay loam Jisan series. The organically cultivated fields were sprayed gelatin and chitin degrading bacteria. The test was performed at conventionally cultivated field and organically cultivated field. Emergence of weed on organically cultivated field was significantly higher than conventionally cultivated field which sprayed herbicide before seeding. Weed emergence have a critical impact on grain yield. Occurrence of diseases and insect pests were higher than conventionally cultivated fields. In 2019, the amount of lodging in conventionally cultivated field were higher than conventionally cultivated field. In 2020, lodging and wet injury were occur in both field. Comparing yield element between organically and conventionally cultivated experimental area, grain yield in organically cultivated field was shown slightly higher amount than conventionally cultivated field. However in the actual yield of 2019, organically cultivated field shows 20% deceased yield because of overgrown weed. In 2020, weed emergence and yellow mosaic virus by wet injury cause 30% decease in the grain yield in organically cultivated field. Content of protein, carbohydrates, ash, water and fat in the grain were not different significance. In 2019, net incomes of conventionally cultivated wheat was 461,031 won/0.1 ha while organically cultivated wheat was 443,437 won/0.1 ha. In the rate of income, conventionally cultivated field was 83.0% as against organically cultivated field (73.3%). In 2020, net incomes of organically cultivated wheat was 437,812 won/0.1 ha while conventionally cultivated wheat was 418,281 won/0.1 ha. In the rate of income, conventionally cultivated field was 81.6% as against organically cultivated field (73.0%).

• Korean journal of applied entomology
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• v.53 no.2
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• pp.135-139
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• 2014

Anastatus orientalis Yang et Gibson(Hymenoptera : Eupelmidae) is the egg parasitoid of lantern-fly Lycorma delicatula. The natural parasitism showed that: (1)the highest parasitism rate of egg masses was 68.96% in Yantai Shandong; (2)the highest parasitism rate of eggs was 32.98% in Haidian Beijing; (3)the eggs of parasitoids hatched and emerged earliest in Yangling Shaanxi; emergence time of different populations in Yantai, Guangang Tianjin, Qinhuangdao Hebei and Haidian was similar; (4) the sex ratios were various among the populations ranging from 1.92 to 1.94; (5) parasitism rates of egg masses on Populus sp., Salix sp. and Toona sinensis were not significantly different, the highest parasitism rate of egg masses was 64.3% on T. sinensis, and the lowest rate was 27.4% on Ailanthus altissima; (6)parasitism rates of eggs on Populus sp., Salix sp., T. sinensis and A. altissima were not significantly different, about 30% averagely.