• 한국작물학회지
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• 제45권4호
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• pp.245-250
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• 2000

This study was conducted to analyze the responses of some agronomic traits to the different cultural environments and relations among the agronomic traits for selecting sesame varieties with higher cultural stabilities. The indexes for stability parameters measured were coefficient of variability, heritabilities, genetic correlations and path coefficients of agronomic traits according to locations and years in Korea. The heritabilities of agronomic traits showed different by locations and years. Number of seeds per capsule and 1000 seeds weight showed higher heritabilities, but stem length and seed weight per plant showed relatively lower heritabilities. Average heritabilities of some agronomic traits in 1998 were comparatively higher than those of 1999. Of six areas, Jinju area showed biggest coefficient of yield variability in 1998-1999. Iksan and Taegu areas showed higher heritabilities in 1998, but Iksan and Jinju areas showed lower heritabilities in 1999. Genetic correlations were slightly higher than corresponding phenotypic correlations. Stem length showed positive genetic correlation with the number of capsules per plant, and seed weight per plant and the number of capsule per plant showed positive genetic correlation with seed weight per plant. On the analysis of path coefficients, stem length and number of capsules effected highly on grain yield. Great regional variations were observed on the effects of agronomic traits on grain yield. Higher direct effects of stem length on grain yield were observed at Suwon, Chungwon, Taegu, Jinju and Naju areas, but in Iksan area was observed higher direct effect of the number of capsules per plant on grain yield in 1998. In 1999, higher direct effect of stem length on grain yield was observed at Chungwon and Suwon areas. Iksan and Taegu areas were also observed higher direct effect of the number of capsule per plant on grain yield.

• 한국작물학회지
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• 제51권6호
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• pp.505-512
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• 2006

In Korea, silicate fertilization (SF) is being practiced every four years to enhance rice production. However, the relationship between nitrogen (N) and SF in view of growth characteristics and grain yield of rice has not been examined after watermelon cropping in plastic film house. This study was carried out to identify useful critical N and Si fertilizer levels to sustain grain yield and to improve N use efficiency for rice. The watermelon-rice cropping system has maintained for three seasons in each year from 1998 to 2001 by farmer before this experiment. Experiments on N and Si fertilization levels were evaluated with Hwayoungbyeo (Oryza sativa L.) in 2002 and 2003 at Uiryeong, Korea. The goal of this experiment was to find out the optimum N and Si levels to sustain rice yield by reducing excessive N fertilizer in watermelon-rice cropping system. Nitrogen fertilization (NF) levels were three ($0,\;57,\;114kg\;ha^{-1};0,\;50,\;100%$ of conventional NF amount) and five (0, 25, 50, 75, 100%) in 2002 and 2003, respectively, and combined with three SF levels ($70,\;130,\;180mg\;kg^{-1};100,\;150,\;200%$ which were adjusted with Si fertilizer in soil) were evaluated for the improvement of N and Si fertilization level in both years. Rice yielded 3.98-5.95 and 2.84-4.02 t/ha in 2002 and 2003, respectively. Our results showed the combinations of 50% and 100% of N with 200% level of Si produced the highest grain yield in both years, respectably. The grain yield was greatly improved in plot of N25% level when compared to conventional NF (Nl00%) in 2003. In conclusion, NF amount could be reduced about 50% compared to recommended level by specific fertilization of N and Si combination levels for rice growing and grain yield after cultivation watermelon in paddy field.

• Journal of Crop Science and Biotechnology
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• 제10권1호
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• pp.33-38
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• 2007

Nitrogen management at the panicle initiation stage(PI) should be fine-tuned for securing a concurrent high yield and high quality rice production. For calibration and testing of the recommendation models of N topdressing rates at PI for target grain yield and protein content of rice, three split-split-plot design experiments including five rice cultivars and various N rates were conducted at the experimental farm of Seoul National University, Korea from 2003 to 2005. Data from the first two years of experiments were used to calibrate models to predict grain yield and milled-rice protein content using shoot fresh weight(FW), chlorophyll meter value(SPAD), and the N topdressing rate(Npi) at PI by stepwise multiple regression. The calibrated models explained 85 and 87% of the variation in grain yield and protein content, respectively. The calibrated models were used to recommend Npi for the target protein content of 6.8%, with FW and SPAD measured for each plot in 2005. The recommended N rate treatment was characterized by an average protein content of 6.74%(similar to the target protein content), reduced the coefficient of variation in protein content to 2.5%(compared to 4.6% of the fixed rate treatment), and increased grain yield. In the recommended N rate treatments for the target protein content of 6.8%, grain yield was highly dependent on FW and SPAD at PI. In conclusion, the models for N topdressing rate recommendation at PI were successful under present experimental conditions. However, additional testing under more variable environmental conditions should be performed before universal application of such models.

• 한국작물학회지
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• 제51권1호
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• pp.1-13
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• 2006

Response of grain yield and milled-rice protein content to nitrogen topdress (N) timing at panicle initiation stage (PIS) is critical for quantifying real-time N requirement for target grain yield and milled-rice protein content. Two split-split-plot experiments with three replications, one in 2004 and the other in 2005, were conducted in Experimental Farm, Seoul National University, Suwon, Korea. The experiments included three N rates at tillering stage (TS), three N timing treatments at panicle initiation stage (PIS) and two rice cultivars. The N rates at TS, N timing at PIS, and rice cultivars were randomly assigned to main plot, sub plot, and sub-sub plot, respectively. Results showed that the delayed N application at PIS reduced grain yield in 2004 and increased milled-rice protein content in both years significantly at 0.05 probability level. The calculated optimum N timing at PIS from pooled data by N rates and rice cultivars in two years was at 28 days before heading (DBH). However, real-time of N timing at PIS was dependent on plant growth and N status around PIS that in turn was dependent on applied N rates at TS. The optimum N timing at PIS was at 30 DBH for no N treatments at TS while at 27 DBH for 3.6 and 7.2 kg N/10a treatments and at 27 and 29 DBH for Hwaseongbyeo and Daeanbyeo, respectively. In general, earlier applied N at PIS resulted in lower milled-rice protein content but the highest grain yield was expected to be obtained when N topdress at PIS was applied at the time when shoot N concentration started to drop below about 23 mg/g due to dilution effect after transplanting. In conclusion, the results of our experiments imply that the currently recommended N topdress time (24DBH) at PIS in Korea should be reconsidered for the higher grain yield and the better quality of rice.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.551-554
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• 2003

This study was carried out to investigate the effects of the pH of irrigation water on the growth, yield, and grain quality of rice. It acquire fundamental knowledges to set up irrigation water quality standards. The pot experiment was conducted with 5 treatments using irrigation waters with various pH values(control, 4, 6, 8, 10) and replicated four times with randomized block design. The results of this study showed that the uptake of N, P, and K, Ripened grain ratio and yield of rice tended to be reduced at the irrigation water of pH 4 and pH 10. P uptake, Ripened grain ratio and yield of rice at pH 4 water were significantly lower than the control. K uptake at pH 10 water was significantly lower than the control. Plant height, SPAD value and protein content of rice were not affected by the pH of irrigation water.

• 한국작물학회지
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• 제35권6호
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• pp.532-538
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• 1990

본 연구는 유전 배경과 초형이 다른 추파소맥 4품종을 공시하였으며, 이들 품종들의 조합배열을 감안하여 단교배 6조합, 3원교배 6조합 및 복교배 3조합을 생산하여 각 교잡방법 및 품종교잡 배열순서에 관한 효율성을 비교 분석하여 교잡육종의 기초자료를 제공하고 신품종 육성의 효율성을 높이고자 시행하였던 바 그 결과를 요약하면, 1. 교배양식간 비교에 있어서 복교잡에서 가장 빠른 출수를 보였으며 종실수량도 20.3g으로서 가장 많았는데 3원교배 및 단교배 순으로 감소하였는데, 친품종들이 가장 적은 주당수량을 보였다. 2. 주당수량과 수량구성요소에 대한 4$\times$4 단교배 Diallel 분석은 GCA와 SCA에서 각각 조합능력의 차가 인정되었으며, 또한 SCA 효과중 평균 우성편차도 역시 모든 형질에서 차가 있었다. 주당수량의 GCA효과는 그루밀과 Bezostaya 1이 가장 높았으며, 이들 품종들이 실제 주당수량이 가장 많았다. 3. F$_1$의 SCA효과는 (은파밀/Bezostaya 1)조합에서 4.22로가장 높았고, (그루밀/은파밀) 조합에서 2.00으로 가장 낮았다. 4. 3조합의 F$_1$ 복교잡종중에서 (Lancota/은파밀//그루밀/Bezostaya 1) 조합이 주당수량 24.5g으로서 가장 많았고, 이러한 복교잡에 이용된 단교잡종(그루밀/은파밀)과 (Lancota/Bezostaya 1)의 복교잡에 직접 발현되지 않고 이들간의 염색체 교환방법에 의하여 결합되어 (그루밀/Lancota), (그루밀/Bezostaya 1), (은파밀/Lancota) 및 (은파밀/Bezostaya 1)의 조합이 발현되었으며, 이들의 단교배 F$_1$들의 평균 수량도 많고 SCA 효과도 높았다. 5. 3원교잡 F$_1$의 6조합중에서(Lan./Bez.//은파밀) 조합에서 21.3g으로 가장 높은 수량을 보였는데, 이들의 염색체의 상호 교환 결합에 의하여(Lancota/은파밀)과 (Bezostaya 1/은파밀) 조합이 SCA효과가 가장 컸고 평균 종실수량도 다른 3원교잡의 경우보다 많았다.

• 한국농림기상학회지
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• 제17권2호
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• pp.156-164
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• 2015

기후변화로 야기되는 미래의 고온 환경은 벼의 생산성을 저하시킬 것으로 예측되고 있다. 본 연구에서는 기후변화에 따른 국내 벼 생산성의 신뢰성 있는 영향평가 기초자료를 확보하기 위해 고온 환경에서의 벼의 수량과 수량 구성 요소의 반응을 조사하고 분석하였다. 실험은 1/5000a 와그너 포트를 이용하여 2008년과 2009년에 걸쳐 서울대학교 부속실험농장($37^{\circ}16^{\prime}N$, $128^{\circ}59^{\prime}E$)의 온도조절 플라스틱 하우스에서 실시되었다. 2008년에는 자포니카계의 화성벼를 공시품종으로 이용하였으며, 시비수준을 $120kg\;N\;ha^{-1}$와 $180kg\;N\;ha^{-1}$로 하였다. 온도처리는 대기온도, 대기온도 대비 $+1.5^{\circ}C$, $+3.0^{\circ}C$의 세 수준으로 하였다. 2009년에는 화성벼와 통일계의 다산벼를 공시품종으로 하여 $120kg\;N\;ha^{-1}$ 수준으로 시비하였다. 온도처리는 대기온도, 대기온도 대비 $+1.5^{\circ}C$, $+3.0^{\circ}C$ 및 $+5.0^{\circ}C$ 수준으로 처리하였다. 수량 및 수량구성요소의 온도처리에 따른 영향은 품종별로 상이한 반응을 보였다. 이삭수와 이삭당 영화수는 두 품종 모두 온도처리의 영향을 받지 않았으나, 천립중과 등숙률에 대해 화성벼는 $5.0^{\circ}C$, 다산벼는 $1.5^{\circ}C$ 이상의 온도처리에서 유의하게 감소하였다. 포트당 수량은 화성벼의 경우 $5.0^{\circ}C$, 다산벼는 $3.0^{\circ}C$ 및 $5.0^{\circ}C$ 온도처리에서 유의한 감소를 나타냈다. 등숙기간 동안의 평균기온에 대한 천립중과 등숙률 반응 또한 품종별로 다르게 나타났다. 다산벼의 경우 $23^{\circ}C$ 이상의 평균 온도에 대해 등숙률과 천립중이 급격히 감소한데 반해, 화성벼는 $23^{\circ}C$부터 $27^{\circ}C$ 범위에 대해 등숙률과 천립중의 변화가 크지 않았다. 기후변화에 의한 지속적인 기온상승이 예상되는 가운데 온도상승에 따른 등숙률과 천립중의 감소는 미래 기후 환경에서의 벼의 수량 감소를 야기하는 주요 원인으로 예측된다. 다만, 상승된 기온에 대한 벼의 반응은 품종별로 상이하기 때문에 고온에 둔감한 품종의 도입 또는 그러한 특성을 지닌 품종의 육종을 통해 기후변화에 따른 수량 감소의 위험을 낮출 수 있을 것이다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2019년도 춘계학술대회
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• pp.9-9
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• 2019

• The Plant Pathology Journal
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• 제35권1호
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• pp.63-70
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• 2019

Winter wheat is susceptible to several fungal pathogens throughout the growing season and foliar fungicide application is one of the strategies used in the management of fungal diseases in winter wheat. However, for fungicides to be profitable, weather conditions conducive to fungal disease development should be present. To determine if winter wheat yield response to fungicide application at the flowering growth stage (Feekes 10.5.1) was related to the growing season precipitation, grain yield from fungicide treated plots was compared to non-treated plots for 19 to 30 hard red winter wheat cultivars planted at 8 site years from 2011 through 2015. At all locations, Prothioconazole + Tebuconazole or Tebuconazole alone was applied at flowering timing for the fungicide treated plots. Grain yield response (difference between treated and non-treated) ranged from 66-696 kg/ha across years and locations. Grain yield response had a positive and significant linear relationship with cumulative rainfall in May through June for the mid and top grain yield ranked cultivars ($R^2=54%$, 78%, respectively) indicating that a higher amount of accumulated rainfall in this period increased chances of getting a higher yield response from fungicide application. Cultivars treated with a fungicide had slightly higher protein content (up to 0.5%) compared to non-treated. These results indicate that application of fungicides when there is sufficient moisture in May and June may increase chances of profitability from fungicide application.

• Applied Biological Chemistry
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• 제16권3호
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• pp.137-145
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• 1973

수량(收量) 등급별(等級別) 영양기준설정(榮養基準設定)을 위하여 전국적(全國的)으로 실시된 수도삼요소시험중(水稻三要素試驗中) 3 개년간(個年間)$(1967{\sim}1969)$의 고(藁) 또는 수분석결과(穗分析結果)에 의(依)하여 수량등급별(收量等級別)로 생육시기별(生育時期別) N,P,K 및 Si의 함량(含量)을 조사(調査)하였다. 수량증가(收量增加)에 따라 양분농도(養分濃度)가 증가(增加)하는 경향은 N>P>K>Si의 순(順)으로 감소(減少)하였다. 그 경향(傾向)은 양분(養分)에 따라서 해에 따라 생육시기별(生育時期別) 보다는 정조수량등급(正租收量等級)에 양분(養分)의 농도변화(濃度變化)가 더 밀접(密接)한 관계(關係)를 보였다.