• Proceedings of the Korean Society of Crop Science Conference
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• 1985.05a
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• pp.13-13
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• 1985

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.366-375
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• 1984

In order to confirm the effect of climatic consumption index (C C I) on the number of spikelets and yield of rice, 3 levels of shading rates such as 0, 25, 50% of full light were treated during the tillering stage, reproductive growth stage and ripening period, respectively, in a phytotron controlled with day/ night temperature of 20/10$^{\circ}C$ and 30/20$^{\circ}C$, and field at Crop Experiment Station, Suwon, Korea. The results are as follows: 1. As solar radiation decreased during the reproductive growth stage in 30/20$^{\circ}C$ or field condition, the number of spikelets per panicle was decreased due to the decrease of the number of differentiated secondary rachis branches and spikelets as well as the increase of the number of degenerated secondary rachis branches and spikelets. 2. Our results showed slight negative correlation between C C I of the reproductive growth stage and number of panicles per square meter and number of differentiated secondary rachis branches. On the other hand, there was highly significant positive correlation between C C I of the reproductive growth stage and the number of degenerated secondary rachis branches and spikelets, and negative correlation in number of differentiated spikelets. 3. The shading during the reproductive growth stage did not affect on the percentage of ripened grains and 1000 grains weight of hulled rice, whereas those were decreased with shading during the ripened period. 4. Influence of shading in each growing stage on the yield was severe in the order of ripened period, reproductive growth stage, tillering stage. 5. Respiration rate in Jinheung was higher than that of Tongil at low temperature, but reversed above 30$^{\circ}C$. Respiratory coefficients (Q$\sub$10/) of Tongil and Jinheung were 2.74 and 1.96, respectively. Respiration/ photosynthesis ratio in Jinheung was higher than that of Tongil at low temperature, while higher in Tongil above 32$^{\circ}C$. 6. Transportation of $\^$14/C was restricted at 20/10$^{\circ}C$ in Tongil, however, there was no differences at 30/20$^{\circ}C$ in both Tongil and Jinheung. The influence of shading on the transportation of $\^$14/C did not affect at 20/10$^{\circ}C$, but it was hampered with shading at 30/20$^{\circ}C$ in both varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.14-18
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• 2010

This study was conducted to investigate the effect of high-temperature during the reproductive growth period on the soybean growth and yield. Two soybean cultivars, Hwangkeumkong (HKK) and Pungsannamulkong (PSNK) were used in this study. By high-temperature treatment, plant height was increased in the two soybean cultivars, however, leaf area and dry weight were greatly reduced. Number of pod per plant was not changed by high-temperature treatment. However, number of seeds and 100 seed weight were reduced in two soybean cultivars. As compared with control, yield were decreased by 45% in both HKK and PSNK. It was also appeared that nitrogen contents in leaf, stem, and root of the HKK and PSNK were decreased by high-temperature treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.479-485
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• 2002

This study was conducted in order to elucidate the effects of nitrogen level and split application method, and shading treatment during reproductive stage on sink formation. Japonica variety Choocheongbyeo and Hwaseongbyeo and indica$\times$japonica cross type variety Nampoongbyeo were used. Five levels (6 to 30 kg/10a at 6 kg/10a interval) of nitrogen fertilization, and two split application methods (50-25-25% and 30-30-40% as basaltillering-panicle fertilizer) for each nitrogen treatment were applied. In addition shading treatments (shading rate, 65%) were performed for N 12 kg/10a and 24 kg/10a plot. Shading were applied for 30 days from panicle initiation to heading, 15 days from panicle initiation and 15days before heading. Panicle per square meter, and primary rachis branches per panicle and differentiated number of secondary branch per panicle increased according as applied nitrogen amount increased up to 18 to 24 kg/10a, and there was no significant difference between two nitrogen application methods. Primary rachis branch and secondary branch per square meter also increased according as the amount of applied nitrogen increase up to 18 to 24 kg/10a, and there was no significant difference between nitrogen application methods. Panicle per square meter and primary rachis branch per panicle were significantly decreased due to shading treatments only in Choochengbyeo. In all varieties, shading reduced secondary rachis branch per panicle significantly and the reduction was greatest in 30 days shading during reproductive stage. Spikelets per square meter increased according as the amount of applied nitrogen increases up to 18 to 24kg/10a, but showed no move increase above this nitrogen application level. Significant difference was not shown between nitrogen split methods. Spikelets per square meter also decreased significantly due to shading treatment during reproductive stage, showing the greatest reduction by 30 days shading during reproductive stage, and the least by 15 days shading during booting stage. The variation of spikelets per square meter was influenced greatest by the variation of panicles per square meter and spikelets per secondary rachis branch.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.142-147
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• 2009

The effects of short-term waterlogging on physiological responses, fatty acid compositions and yield components of rapeseed at both the vegetative growth and the reproductive growth stages were assessed in this study. Waterlogged plants were treated for a period of 10 days at the vegetative growth stage and 4 days at the reproductive growth stage. The results show that photosynthesis and stomatal conductance at both the vegetative growth and the reproductive growth stage were significantly reduced during the waterlogging period and after the recovery period. When the plants were removed from water, photosynthesis and stomatal conductance progressively restored similar values to those of control plants within $2{\sim}3$ days. Fatty acid compositions were unaffected by waterlogging treatment. However, yield components (pod number and pod length) of the waterlogged treated plants at the reproductive growth stage were significantly reduced. These results suggest that short-term waterlogging may thus influence oilseed yield component.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.2
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• pp.122-126
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• 1989

The study was performed to examine varietal differences of wilting injury in terms of the root developing system and root activity. The field survey was conducted at the farmer's, and the experimental fields. The experimental investigation was done at different growth stage of rice plant in the sand culture condition. The results were summarized as follows: 1. The T/R ratio of healthy plants was greater than that of the wilted plants in Yushin. 2. Regardless of plant parts, the root activity of the wilted plants decreased in Yushin. The T/R ratio of Yushin tended to increase at the vegitative stage while the Photosynthate distribution to root decreased at the later stage. 3. The root activity and the plant growth rate were higher at vegetative growth stage, while the root activity at reproductive stage decreased. 4. The root activity of Milyang 23, which has relatively less injury of wilting, did not significantly differ between the wilted and the healthy plants. The root was thick and T/R ratio was low.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.87-89
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• 2003

벼의 생육과 수량에는 토양과 생물환경 못지 않게 기상환경도 중요하다. 기상환경 중에서도 기온과 일조시수의 영향은 매우 커서 이에 대한 연구가 많이 이루어 졌다. 따라서 본 시험에서는 여수지역에서의 10년간 기상조건과 벼의 수량성을 비교하였던바 생육 초기의 영양생장기에 비하여 생육후기의 생식 생장기에서의 높은 고온과 많은 일조시간(일사량)은 증수되는 경향이 었다.

• Proceedings of the Korean Society of Crop Science Conference
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• 1985.05a
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• pp.14-14
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• 1985

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.135-139
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• 1998

Reciprocal interspecific hybrids between N. glauca(2n=24) and N. langsdorffii(2n=18) were obtained by intercrossing. One hundred percent of F$_1$ seeds was produced from intercrossing of N. glauca $\times$ N. langsdorffii, whereas the frequency of F$_1$ hybrid seed formation from N. langsdorffii $\times$ N. glauca was very low. However, all the hybrid seeds were germinated well and then grown to normal plantlets. All the plants of F$_1$ hybrids have chromosome number of interspecific hybrids (2n=21). From observation of morphological characteristic, the structure of petrol, leaf, flower, and the morphology of pollen have characteristics of F1 hybrid. Spontaneous tumors (genetic tumor) were formed from each F$_1$ hybrid; the genetic tumor arose at the reproductive phase when the maternal type of F$_1$ hybrid came from N. glauca, while the genetic tumor arose only after reproductive phase when the maternal type of F$_1$ hybrid came from N. langsdorffii. The genetic tumor actively proliferated on hormone-free medium and produced numerous teratoma shoots. In addition, normal leaf or stem explants of F$_1$ hybrid produced calli on hormone-free medium after 15 days of culture, the calli produced new numerous teratoma shoots after 30 days. The frequency of teratoma shoot formation from rnterspecific hybrid was higher in the N. glauca $\times$ N. langsdorffii than in the N. langsdorffii $\times$ N. glauca. Root development from the teratoma shoots was hardly obtained. Teratoma shoots without roots in vitro can form genetic tumor at the vegetative growth phase after tissue culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.241-247
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• 2001

Boundary line method was adopted to analyze the relationships between rice yield and meteorological conditions during rice growing period. Boundary lines of yield responses to mean temperature($T_a$) and sunshine hour( $S_{h}$) and diurnal temperature range($T_r$) were well-fitted to hyperbolic functions of f($T_a$) =$$\beta$_{0t}$(1-EXP(-$$\beta$_{1t}$ $\times$ ($T_a$) ) and f( $S_{h}$)=$$\beta$_{0t}$((1-EXP($$\beta$_{1t}$$\times$ $S_{h}$)), to quadratic function of f($T_r$) =$\beta$$_{0r}$(1-($T_r$ 1r)$^2$), respectively. to take into account to, the sterility caused by low temperature during reproductive stage, cooling degree days [$T_c$ =$\Sigma$(20-$T_a$] for 30 days before heading were calculated. Boundary lines of yield responses to $T_c$ were fitted well to exponential function of f($T_c$) )=$\beta$$_{0c}$exp(-$$\beta$_{1c}$$\times$$T_c$ ). Excluding the constants of $\beta$$_{0s}$ from the boundary line functions, formed are the relative function values in the range of 0 to 1. And these were used as yield indices of the meteorological elements which indicate the degree of influence on rice yield. Assuming that the meteorological elements act multiplicatively and independently from each other, meteorological yield index (MIY) was calculated by the geometric mean of indices for each meteorological elements. MIY in each growth period showed good linear relationship with rice yield. The MIY's during 31 to 45 days after transplanting(DAT) in vegetative stage, during 30 to 16 days before heading (DBH) in reproductive stage and during 20 days after heading (DAH) in ripening stage showed greater explainablity for yield variation in each growth stage. MIY for the whole growth period was calculated by the following three methods of geometric mean of the indices for vegetative stage (MIVG), reproductive stage (HIRG) and ripening stage (HIRS). MI $Y_{I}$ was calculated by the geometric mean of meteorological indices showing the highest determination coefficient n each growth stage of rice. That is, (equation omitted) was calculated by the geometric mean of all the MIY's for all the growth periods devided into 15 to 20 days intervals from transplanting to 40 DAH. MI $Y_{III}$ was calculated by the geometric mean of MIY's for 45 days of vegetative stage (MIV $G_{0-45}$ ), 30 days of reproductive stage (MIR $G_{30-0}$) and 40 days of ripening stage (MIR $S_{0-40}$). MI $Y_{I}$, MI $Y_{II}$ and MI $Y_{III}$ showed good linear relationships with grain yield, the coefficients of determination being 0.651, 0.670 and 0.613, respectively.and 0.613, respectively.