• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.132-132
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• 2022

The application of direct seeding cultivation reduces time, labor, and cost. However, this application often has poor seedling establishment and leads to lower yield as compared to transplanting system. The tolerance to anaerobic and low temperature germination is important to improve seedling establishment and the wide-spread application of direct seeding method. This study was carried out to evaluate the responses of three japonica cultivars to different temperatures (15℃, 18℃, 21℃, 24℃, and 27℃) and different flooding levels (1 cm, 4 cm, 7 cm, 10 cm) during germination and seedling development. The mean survival percentage significantly increased (P<0.05) when the flooding level decreased and when temperature increased. There were significant effects of the interaction between temperature and water depth on survival percentage and seedling height. When temperature decreased from 27℃ to 15℃, the germination duration significantly increased from 6.4 days to 16.3 days while the germination speed, survival percentage, and seedling height decreased from 5.3 seeds day^-1, 61.9% and 190.6 cm to 2.2 seeds day^-1, 33.2%, and 47 cm, respectively. The increase in temperature under submergence condition was associated with the increased expression of Amy3D and ALDH2a but the decreased expression of ADH1 and PDC1. The results of this research would be used for further studies and breeding programs to improve rice seedling establishment and the application of direct seeding cultivation.

• 생물환경조절학회지
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• 제7권2호
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• pp.109-115
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• 1998

본 실험은 꽃도라지의 고온기 육묘시 유묘의 저온처리기간에 따른 정식 후 생장과 개화반응을 조사하기 위하여 수행되었다. 본엽이 4매 전개된 유묘를 1$0^{\circ}C$의 인큐베이터에 각각 2, 3, 4, 5주 동안 저장하였다. 비교를 위해 저온저장하지 않은 식물체와 각각의 기간동안 저온처리된 식물체는 최저 야온 12~13$^{\circ}C$, 자연일장 조건의 유리온실에 정식하여 관리하였다 아즈마설과 아즈마훈 품종의 경우 경경과 엽수에서는 처리간 차이가 없었다. 그러나 초장 절간장 지상부 생체중 및 건물중은 4주동안의 처리구에서 현저하게 증가하였다. 두 품종 모두에서 4주 동안의 저온처리는 꽃의 무게와 직경의 크기를 증가시켰으며 개화소요일수도 무처리구와 2주 처리구에 비해 20일이 단축되었다. 아즈마조 품종의 지상부생육은 4주 동안의 저온처리구에서 증가되었으며 꽃의 품질도 향상할 수 있었다. 개화소요일수는 4주 동안의 저온처리구에서 무처리구보다 31일 2주 처리구보다는 36일이 단축되는 결과를 보였다. 실험 결과 꽃도라지 아즈마설, 아즈마혼, 아즈마조 품종의 고온기 육묘시 유묘의 최적 저장 조건은 1$0^{\circ}C$에서 4주간이었다

• 한국잡초학회지
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• 제30권3호
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• pp.206-214
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• 2010

The laboratory and green house studies evaluated the effect of three different environmental factors on the seed germination, seedling emergence and survival of four major weed species in coconut plantations, Mimosa pudica, Ureana lobata, Panicum maximum and Pennisetum polystachyon. Germination percentage of all the weed species was significantly reduced with increasing soil moisture stress, no germination was observed at -0.9 MPa. Germination of both grass seeds ranged from 8% to 25% and 10% to 45% as moisture stress decreased from -0.4 MPa to 0 MPa, respectively. In contrast, seeds of M. pudica, and U. lobata were moderately tolerant to soil moisture stress and best adapted to moist environment. All the weed species seeds germinated over a wide range of soil pH values with the highest germination occurring at pH 6. In all the species, seedling emergence was declined rapidly with increasing depth with the exception of U. lobata. Seedling emergence significantly declined when the duration of flooding was three days or longer in dicotyledonous weed species and two days or longer in monocotyledonous weeds. This study illustrates the adaptability of these weeds to different environmental conditions which would enable the development of management strategies to reduce their populations below economic threshold levels in coconut plantations.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1999년도 춘계 학술대회지
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• pp.71-72
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• 1999

• 한국작물학회지
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• 제34권4호
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• pp.434-439
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• 1989

벼 어린모의 육묘온도별 최소 육묘일수를 구명하고 육묘온도, 육교일수 및 배유제거유무에 따른 이앙후 초기생육을 조사한 결과를 요약하면 다음과 같다. 1. 벼 어린모 육묘시 육묘오도에 따른 최소 육묘일수를 맷트형성정도를 기준으로 보면 20/12$^{\circ}C$ 서/ 야)에서는 10일, 25/18$^{\circ}C$에서는 8일, 30/2$0^{\circ}C$에서는 6일어었다. 2. 벼 어린모 육묘시 유교온도에 따른 최소 육묘일수의 묘생육을 보면 초자은 8~12cm, 엽수(불완전엽 제외)는 1.5~1.7엽, 지상부 건물중은 개체당 6.9~7.5mg, 배유양분잔존율은 32~36%이었다. 3. 벼 어린모 육묘시 육묘온도에 따른 최소 육묘일수의 적산온도는 육묘온도에 따라 다소 다르나 150~17$0^{\circ}C$의 범위이었다.

• 한국작물학회지
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• 제39권5호
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• pp.502-511
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• 1994

벼 건답직파에서 벼 품종들의 출아·입모 특성과 유아의 신장 특성과의 관계를 검토하고자 국내의 재래종, 육성종 및 샤레벼, 미국 직파재배품종, 이태리 품종 등 98개 품종을 토중 4.5cm에 파종하여 적습과 과습조건하에서 출아율, 입모율, 평균출아일수, 중배축장, 하위절간장, 초엽장, 불완전엽장 등을 조사하여 얻은 결과는 다음과 같다. 1. 적습조건에서 입모율은 9∼92.5%, 평균출아일수는 12∼25일 범위였고, 과습조건에서의 출아율은 0∼90%, 평균출아일수 27∼34일로 양조건 모두 품종간 변이가 매우 컸으며, 대부분의 품종은 과습조건에서 출아율이 낮아지고 출아속도가 늦어졌다. 2. 출아·입모율과 유의한 정의 상관을 보인 형질은 적습조건에서는 중배축장, 초엽장, 불완전엽장이었고, 과습조건에서는 중배축장, 제1, 2절간장, 초엽장, 불완정엽장이었다. 3. 평균발아일수는 중배축장, 초엽장, 불완전엽장과 유의한 부의 상관을 나타내었다. 4. 표준편회귀분석결과 출아·입모의 품종간 차이에 가장 유의적으로 기여하는 형질은 적습조건에서는 중배축장과 초엽장, 과습조건에서는 중배축장과 제2절간장이었다. 5. 평균출아일수의 품종간 차에 유의적으로 기여하는 형질은 적습조건에서는 중배축장, 불완전엽장으로 회귀계수는 부의 방향이었으며, 제1,2절간장은 정의 방향이었다. 과습조건에서는 중배축장만이 유의적 기여를 하였는데 회귀계수는 부의 방향이었다. 6. 본 실험의 결과로 볼 때 건답직파조건에서 출아율이 높고 출아속도가 빠른 품종을 육성하기 위해서는 중배축, 초엽 및 불완전엽의 신장이 잘되는 특성의 선발이 바람직한 것으로 사료된다.

• 한국자원식물학회지
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• 제19권6호
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• pp.687-691
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• 2006

This experiment was conducted on rice (cv. 2005 Thaoi) seeds to study whether priming with deep sea water (DSW) results in enhancement of seed emergence and seedling growth and to identify the optimum concentration of Deep Sea Water (DSW) for priming. Two experiments were conducted subsequently. In experiment 1, four concentrations of the DSW (10%, 20%, 30% and 40%), and in experiment 2, five concentrations of DSW (10%, 15%, 20%, 25% and 30%) were prepared and seeds were primed for 24 hours duration at $25^{\circ}C$. Beside this, hydro priming with plain water was also included as a control. Experiments were laid out in Completely Randomized Design (CRD) with three replications. Result showed that 20% DSW seed priming treatment had improved the emergence, seedling height, number of roots and root length as compare to other with DSW or without DSW treatments. Beyond 20% DSW priming (i.e. 25%, 30% and 40%) were not suitable for priming the seed. On the basis of seedlings growth parameters; emergence, seedling height, root number and length, and shoot root ratio, 20% DSW priming was the best priming treatment.

• 한국연초학회지
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• 제7권1호
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• pp.25-31
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• 1985

For shortening the tobacco breeding cycle, seedlings with 6, 8 and II leaves of 2 flue.cured tobacco varieties, day. neutral type and photoperiod-sensitive type, were grown in controlled-environment room (CER), programmed for temperature of $18^{\circ}C$ and 8.hour day period of 30 klux, for 20, 30 and 40 days. All of plants of day.neutral type variety treated in CER, regardless of seedling stage and duration, flowered earlier than the untreated plants. In the 6.leaf seedlings stage of photoperiod-sensitive type variety, plants treated for 20 and 30 days in CER did not accelerate the flowering. the tobacco plants, treated with low temperature for 20 days at 8.leaf seedling stage, flowered earlier in comparison with. the other treatment.

• 한국작물학회지
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• 제36권2호
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• pp.112-126
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• 1991

The atmospheric carbon dioxide concentration is ever-increasing and expected to reach about 600 ppmv some time during next century. Such an increase of $CO_2$ may cause a warming of the earth's surface of 1.5 to 4.5$^{\circ}C$, resulting in great changes in natural and agricultural ecosystems. The climatic scenario under doubled $CO_2$ projected by general circulation model of Goddard Institute for Space Studies(GISS) was adopted to evaluate the potential impact of climate change on agroclimatic resources, net primary productivity and rice productivity in Korea. The annual mean temperature was expected to rise by 3.5 to 4.$0^{\circ}C$ and the annual precipitation to vary by -5 to 20% as compared to current normal climate (1951 to 1980), resulting in the increase of possible duration of crop growth(days above 15$^{\circ}C$ in daily mean temperature) by 30 to 50 days and of effective accumulated temperature(EAT=∑Ti, Ti$\geq$1$0^{\circ}C$) by 1200 to 150$0^{\circ}C$. day which roughly corresponds to the shift of its isopleth northward by 300 to 400 km and by 600 to 700 m in altitude. The hydrological condition evaluated by radiative dryness index (RDI =Rn/ $\ell$P) is presumed to change slightly. The net primary productivity under the 2$\times$$CO_2$ climate was estimated to decrease by 3 to 4% when calculated without considering the photosynthesis stimulation due to $CO_2$ enrichment. Empirical crop-weather model was constructed for national rice yield prediction. The rice yields predicted by this model under 2 $\times$ $CO_2$ climatic scenario at the technological level of 1987 were lower by 34-43% than those under current normal climate. The parameters of MACROS, a dynamic simulation model from IRRI, were modified to simulate the growth and development of Korean rice cultivars under current and doubled $CO_2$ climatic condition. When simulated starting seedling emergence of May 10, the rice yield of Hwaseongbyeo(medium maturity) under 2 $\times$ $CO_2$ climate in Suwon showed 37% reduction compared to that under current normal climate. The yield reduction was ascribable mainly to the shortening of vegetative and ripening period due to accelerated development by higher temperature. Any simulated yields when shifted emergence date from April 10 to July 10 with Hwaseongbyeo (medium maturity) and Palgeum (late maturity) under 2 $\times$ $CO_2$ climate did not exceed the yield of Hwaseongbyeo simulated at seedling emergence on May 10 under current climate. The imaginary variety, having the same characteristics as those of Hwaseongbyeo except growth duration of 100 days from seedling emergence to heading, showed 4% increase in yield when simulated at seedling emergence on May 25 producing the highest yield. The simulation revealed that grain yields of rice increase to a greater extent under 2$\times$ $CO_2$-doubled condition than under current atmospheric $CO_2$ concentration as the plant type becomes more erect.

• 한국환경과학회지
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• 제32권2호
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• pp.121-130
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• 2023

This study was conducted to investigate changes in seed vigor based on temperature of dry heat and duration treatment of watermelon seeds and examine the effect on percent of emergence and seedling vigor. When the upper limit temperature of dry heat treatment was raised to 80℃, the percent of the germination decreased. Moreover, T₅₀ was delayed as the upper limit temperature of dry heat treatment increased. The higher the upper limit temperature of dry heat treatment and the longer the treatment period, the higher the percentage of abnormal seedlings. The optimum upper limit temperature for dry heat treatment was 72℃, and the treatment period was five days. Seed vigor was better maintained at 30℃, 45℃, and 52℃, followed by stepwise exposure to high temperatures of 72℃, the upper limit of dry heat treatment, rather than dry heat treatment at a high temperature of 72℃ for 5 days from the initial stage of treatment. When the fungicide was added during the dry heat treatment process, the germination percentage decreased and the percent of the abnormal seedling percentage increased. However, the addition of 10 mg/kg fungicide did not significantly reduce seed vigor.