• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.2
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• pp.146-152
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• 2015

Early-maturing Korean Japonica cultivars and Jungmo1024 were used as plant materials to evaluate hightemperature tolerance during grain filling stage. National Institute of Crop Science (NICS) in Korea developed Jungmo1024, a mutant line from Namil (wild type) treated by using sodium azide (SA) as mutagen. To evaluate high-temperature tolerance, all cultivars were exposed to high-temperature (day $31.5{\pm}2.5^{\circ}C$/ night $27.5{\pm}1.3^{\circ}C$) and ordinary temperature (day $27.5{\pm}1.8^{\circ}C$/ night $24.7{\pm}1.6^{\circ}C$) during grain filling stage. In these conditions, we performed compared evaluation of grain shape such as length and width and grain quality by using a 1625 Cervitec grain inspector. High-temperature during grain filling stage caused decrease of grain shape. In grain shape such as length and width, the decrease rate of width (average 6.3%) was higher than the decrease rate of length (average 1.3%). Hence, high-temperature affected width of grain than length of grain. In addition, high-temperature showed a decided difference in rate of head rice between ordinary temperature (average 76.3%) and high-temperature (average 13.3%).As a result, Taebong, Ungwang, Manan, and Jungmo1024 seemed relatively a decent high-temperature tolerance than other cultivars. Especially, Jungmo1024 seemed remarkable rate of head rice (average $34.4{\pm}6.2%$) than other cultivars under high-temperature. It is considered that a genetic trait of Jungmo1024 can be useful to improve breeding for high-temperature tolerance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.465-468
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• 2003

In order to find out the basic information for salt tolerance in vice (Oryza sativa L.), effects of NaCl treatment on absorption of inorganic components and growth were investigated in 6 japonica and 5 tongil varieties and compared to the salt tolerance variety, Annapurna. The absorption of N and $\textrm{P}_2\textrm{O}_5$ was less repressed than that of $\textrm{K}_2\textrm{O}$, MgO, CaO, and $\textrm{Si}\textrm{O}_2$ which were a little affected by NaCl treatment. $\textrm{K}_2\textrm{O}$ was the most highly repressed component in the absorption of inorganic components, followed by MgO, CaO, total-N, $\textrm{P}_2\textrm{O}_5$ and $\textrm{Si}\textrm{O}_2$. $\textrm{Na}_2\textrm{O}$ content was increased about twenty times to the control at 30days after NaCl treatment, and tonsil varieties more than absorbed japonica ones. Dry weight of japonica varieties by NaCl treatment was less reduced than that of tonsil varieties, followed by Seomjinbyeo, Sinseonchalbyeo, Nakdongbyeo, Daechoungbyeo, Dongjinbyeo and Chuchoungbyeo in japonica group, and Milyang30, Gayeabyeo, Jangseongbyeo, Chilseongbyeo and Taebackbyeo in tonsil group. The relationship between dry weight reduction and Na/K ratio showed positively significant correlation in rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.378-383
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• 1997

Bird damages are often occurred at the seeding and seedling stages of crops. What the bird damage is preventing from the seeding and seedling of rice in the paddy would be very important to get high yield. Methiocarb was formulated as a bird repellent of crop seeding and seedling. Its effects on the seedling growth, related to the chemical injuries and the bird damages, were examined at the seeding and seedling growth stages of Anjungbyeo(Oryza sativa L.) with different types and amounts of methiocarb treatment in both pot and field experiments. In the pot experiment, bird damages were not occurred at all treatments of methiocarb, while bird damages were occurred at the control; 30, 85, and 100％ of damages at 5, 10, and 15 days after seeding, respectively. The ratio of seedling stand was not significantly different among all of treatments, methiocarb, methiocarb＋thiram, and control. However, the plant height and the number of seedling leaves at 15 days after seeding was shortened and lowered statistically more at treatment of methiocarb 15g than those of methiocarb 10g and control. The plant height at 35 days after seeding, showing the recovery degrees of chemical injuries, was significantly lowered in treatment of methiocarb＋thiram 15g, whereas the plant height of methiocarb FS 15g was not significantly differed from that of the control. In the field study, the bird damages were significantly reduced in treatment of methiocarb compared to that of the control. The plant height and the number of leaves at 25 days after seeding were not differed statistically among all of treatments. The chemical injuries were occurred in all treatments of methiocarb at 10 days after seeding, while they were not shown at 20 days after seeding.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.317-326
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• 1996

To know whether pyrazosulfuron-ethyl(PYR) and imazaquin(IMA), known as a acetolactate synthase(ALS) inhibitors, have a same herbicidal action pattern in rice(Oryza sativa) or barnyardgrass (Echinochloa crus-galli), an inhibition pattern and a response characteristics in combination with dymron or butachlor were investigated. In contrast to the phytotoxicity of rice treated with IMA, the one treated with PYR was completely tended to be recovered after 25 days after treatment. Safening effect of dymron against PYR was effectively developed to transplanted-rice, while such an effect was not shown in combination with IMA. In combination with PYR and butachlor, antagonistic effect was observed in both simultaneous or sequential treatment on bamyardgrass, however, additive effect was rather shown in combination with IMA and its activity was dominantly dependent on the first applied compound. $I_{50}$ of PYR and IMA on the ALS extracted from barnyardgrass was $4{\times}10^{-7}$M and $2.8{\times}10^{-6})$M, respectively. Butachlor did not affect their activities on ALS in vitro. These results suggest that PYR and IMA might have a different action each other in the pathway to a final herbicidal activity even though their primary action site is ALS.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.503-514
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• 1997

The morphogenesis of panicle and spikelet in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in $5000^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicle of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage until heading stage. Although the date of panicle differentiation and heading in Koshihikari earlier than those of Milyang 23. the sequence of panicle development in two cultivars begins when first bract primordium at opposite side of flag-leaf primordium differentiated, synchronously followed by growth of the primary branch primordia (PBPs) and secondary branch primordia (SBPs), spikelet primordia(SPs), glumes as lateral organs on rachilla and organs composing single floret, and successive sporogenesis in the young spikelets continue after the enclosure by lemma and palea. The PBPs are acropetally initiated from the base of the panicle primordium, and the SBPs alternately differentiate from the base of upper PBP which differentiate later than the lower PBP. Spikelet development starts at the top of upper side PBP of the young panicle and continue basipetally even though SBPs continue to develop at the lower primary branch. Each PBP, SBP and SP differentiate with differentiation bract or bract hair cell around the base of each their primordia. The observation could confirm that Milyang 23 has not only 2~3 more defferentiated PBPs, but also more SBPs and SPs especially from middle-lower primary branch, at end of their differentiation stages, as compared to those of Koshihikari.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.137-143
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• 2008

Rapid canopy closure (RCC) is one of the physiological attributes that may enhance genetic yield potential of rice (Oryza sativa L.) in a growing season. Crop growth before canopy closure could be described by an exponential equation of $y\;=\;{\alpha}{\cdot}{\exp}({\beta}{\cdot}t)$ where $\alpha$ is the crop leaf area index (LAI) or shoot dry weight (DW), t is the thermal time, $\beta$ is the LAI or DW at the beginning of the exponential growth and is the relative growth rate of LAI ($m^2m^{-2}^{\circ}C^{-1}$) or DW($gg^{-2}^{\circ}C^{-1}$). Field experiment using 22 cultivars revealed that the exponential growth phase before canopy closure can be divided into two sections; an earlier section during which crop dry weight and LAI of varieties are highly dependent on $\alpha$ and a second section where crop dry weight and LAI are highly dependent on $\beta$. Grain weight had significantly positive correlation with $\alpha$ parameter and dry weight and LAI during early exponential phase. The parameter $\beta$ of the exponential growth curve had positive and significant correlation with the LAI and dry weight during the late exponential growth phase, grain number per unit area, and grain yield. There was genotypic difference for RCC parameters, $\alpha$ and $\beta$, indicating the possibility of genetic improvement for these traits.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.833-840
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• 1997

Differentiation and degeneration of spikelets in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in 5000$^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicles of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage, and investigated about formation position of the differentiation and degeneration spikelet within a panicle of 7 days after heading. The degeneration of spikelet appeared simultaneously throughout panicle just after closure of spikelet by the palea and lemma. Differentiated and degenerated spikelets per panicle were about 240, 80 for Milyang 23 and 87, 6 for Koshihikari, respectively. The spikelets degeneration in Milyang 23 was mainly on the secondary and tertiary branch which were developed from primary branch of middle-basal panicle node and hardly not the spikelets of primary branch, and degeneration rate of secondary and tertiary rachis branch and spikelets for Milyang 23 were 2.5 times greater than those of Koshihikari. The proper relation equation between total differentiation or normal spikelets number per panicle(Y) and each rachis branch number were different between cultivars, Le., Y=5.5X$_1$＋3.0X$_2$ for Koshihikari as previously proposed, but those of Milyang 23, Y=5.7X$_1$＋3.5X$_2$＋2.8X$_3$ for total differentiation spikelets and Y=5.6X$_1$＋3.2X$_2$＋2.4X$_3$ for normally developed spikelets, where X$_1$, X$_2$, X$_3$ are number of primary, secondary, tertiary rachis branch, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.2
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• pp.79-84
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• 1977

In order to confirm the effect of potash top dressing and to observe the effect of N, K compound fertilizers, 17-0-17, 17-0-14, and 15-0-20, specially prepared for top dressing to rice, a field experiment with rice (Oryza Sativa L., Akibare) was conducted in a poorly drained paddy field in comparison with potassium chloride. The results obtained are as follows, 1. The effect of potash top dressing to rice was so remarkable that the yield from the plots of split application of muliate potassium or compound fertilizer was significantly higher than that from the plot received no potash at all. In contrast, the plots received all the amount of potash as one dose at transplanting time showed no significant increase in yield compared with that of potash plot. 2, The effect of N, K compound fertilizer, granulated to about the size of a small bean appeared to be so slow that it gave little increase of yield when it was appiled as a top dressing at the primodial stage, but it gave an increase of yield when it was top dressed at effective tillering stage. 3, Granular N, K compound fertilizer to be top dressed at primodial stage might be prepared in small size so that the fertilizer readily go into solution when it was applied, otherwise the fertilizer should be applied eariler than the primodial stage.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.484-489
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• 2010

The cultivation of green manure crops plays an important role in soil quality and sustainability of agricultural system. However, the incorporation of green manure crops may be of concern because it can lead to strongly reducing conditions in the submerged soil. This study was conducted to evaluate the effects of rice husk carbon on rice (Oryza sativa L.) cultivation using green manure mixtures (hairy vetch + rye) in rice paddy. Field experiments were conducted in rice paddy soil (Shinheung series, fine loamy, mixed, nonacid, mesic family of Aeric Fluventic Haplaquepts) at the National Institute of Crop Science (NICS), Korea from October 2007 to October 2008. The experiments consisted of three treatments: application or no application of carbonized rice husk, and conventional fertilization. These treatments were subdivided into whole incorporation and aboveground removal of green manure mixtures. The redox potential (Eh) was higher upon application of the carbonized rice husk when compared to no application at 8 and 37 days after transplanting (DAT). The ammonium-N ($NH_4$-N) in soil was highest upon the application of carbonized rice husk + whole green manure incorporation at 17 and 49 DAT. Plant height and tiller number of rice were similar to the $NH_4$-N concentration in soil. Rice yields of application and no application of carbonized rice husk treatment were not significant. However, application of carbonized rice husk improved the soil physical properties such as bulk density and porosity after rice harvest. Therefore, the results of this study suggest that carbonized rice husk could be used as soil amendment for environmentally-friendly rice production under a green manure mixture-rice cropping system.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.143-150
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• 1983

Red rice (local name "Sore") as a weed has been a serious threat to rice production in direct-seeded rice culture in Ganghwagun, Gyeonggi province. In the Ganghwagun 508 ha out of 1,420 ha in the Samsanmyeon area is infested with red rice. The average lowland rice yield is about 4,300 kg/ha in the Ganghwagun, but the average upland rice yield is about 2,000 kg/ha in infested area. This study was carried out in order to clarify the ecological characteristics of red rice and factors affecting the competitive ability of five red rice varieties, collected from Samsanmyeon in 1981, with rice cultivar. Five varieties-Monggeunsare, Salsare, Ginkaragsare, Galsaegsalsare, Galsaegkaragsare-showed the same morphological characteristics of cultivated Japonica type, Chuncheongbyeo, but red rice tillers more profusely, is taller and lodges more easily than Chucheongbyeo. It shatters easily about 10-15 days after heading date, and at this time the hull is discolored in yellow or dark brown. There are many types of red rice with short or long owns on the spikelet, occasionally with or without own on the spikelet in the same hill, and the grains are short or long. In red reice leaf blast occurs more severely than in cultivated Indica/Japonica type, Teabaegbyeo, particulary serious in Monggeunsare. When red rice invaded in direct-seeded rice, number of panicles of rice became reduced more than other yield components.