• Research in Plant Disease
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• v.7 no.2
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• pp.107-111
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• 2001

Deterioration of pod and seed quality by pod and stem blight and purple blotch is a serious problem in the production of vegetable soybean. Major inoculum sources for the causal pathogens, Phomopsis spp. and Cercospora kikuchii, are soybean straw and debris. Phomopsis spp. have been known to be either limited for hyphal growth or latent in immature soybean tissues. In this experiment, cultural practices using these ecological traits of the pathogens were applied as a control measure. In plastic mulching, seed infection was remark ably reduced by drip irrigation as compared to overhead sprinkling, but not reduced in no mulching cultivation. Control value of plastic mulching was 28.0% for pod and stem blight and 29.3% for purple blotch, which was lower than that of benomyl application. By the first week in June, 78% of overwintered soybean straw examined contained matured alpha spores in pycnidia, acting as primary inoculum. Secondary inoculum of phomopsix spp. was observed abundantly throughout from mid June to September on fallen cotyledons from current crops and subsequently was found on petiole debris. Consequently, both plastic mulching and drip irrigation were effective to some extent for controlling pod and stem blight and purple blotch without significant reduction in soybean yield, and the cultural practices in combination with field sanitation resulted in removing more the secondary inoculum.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.4
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• pp.177-184
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• 2001

This study was conducted to identify the optimum nitrogen (N) fertilization at panicle initiation stage on ridge direct seeding on dry paddy of rice. During 1999~2000, a series of experiments was carried out at field (Chonbuk series) of the National Honam Agricultural Experiment Station, RDA using Dongjinbyeo. Plants were taller, and leaf area index and top dry weight increased with more N fertilization at panicle initiation stage. Photosynthetic rate of heading stage was higher at higher amounts of N fertilization at panicle initiation stage, especially in 6 kg/10a compared with 10 kg/10a seeding rate. Lodging index and its related traits did not significantly differ under different rates of N fertilization at panicle initiation stage. N uptake of the rice plant increased as more N fertilization at panicle initiation stage. N use efficiency was highest under the standard topdressing rate at 6 kg/10a seeding rate. Panicle number per m$^2$ increased with more topdressed N, but ripened grain rate and 1,000-grain weight of brown rice did not differ with an increase in topdressed N. Milled rice yield was 6% higher in the 6 kg/10a seeding rate and 13% higher in the 10 kg/10a seeding rate at 50% more topdressed N compared with 4.8 kg/10a N fertilization at panicle initiation stage of 6 kg/10a seeding rate.

• Journal of Life Science
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• v.8 no.4
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• pp.437-442
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• 1998

Seed and leaf size is the important morphological traits considered by plant breeder and is the important yield components in soybean. The objective of this research was to know the relationship between seed size and leaf size in 66 $F_2$ populations derived from half diallel mating system with 12 soybean strains, representing distinct seed and leaf size. The range of seed size for 12 parents used was 6.7 to 43.8 g/100 seed. Leaf width leaf length ranged 5.7 to 8.6 cm and 9.4 to 12.9 cm, respectively. Leaf width was highly correlated with leaf length with an R square of 0.754 in the $F_2$ generation. The $F_2$ regression` coefficient indicated that leaves were, on average 1.4 times greater length than in width . Leaf size (width) was highly correlated (r.0.91) with seed size (g/100 seed) in the $F_2$ generation with an R square of 0.833. Our results indicate postive correlation within seed and leaf size is common in $F_2$ segregating populations derived from crossing with soybean. The strong liner relationship we observed between leaf size and seed size in $F_2$ segragating population is useful in that in that indirect selection for a secondary character may be superior to direct selection for the primary character.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.55-64
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• 1990

Cell volume and DNA contents of the fusants were similar to those of parents. Genetic stability of the fusants was increased when they were cultured on minimal medium (MM) rather than on complete medium (CM), and the fusants were stabilized by subculturing 7 generations each 7 day on MM agar. The finally selected fusants after being cultured for 6 months on CM were stable without segregation. The fusants could also form nuclein and ascospores, and show red and pink colors by the test of TTC colorization. Assimilability and fermentability of carbon sources of the fusants were similarto those of parents. The tolerance of KCl, NaCl, sodium propionate and cycloheximide showed the traits of one strain of parents. When the fusants were cultured for 72 hr and 60 hr in the medium containing 20% glucose and sucrose, respectively, the yield of ethanol for FWKS 260 was reached to 9.6 v/v% and 9.8v/v%, respectively. The sensitive strain Kyokai 7 was found to be killed entirely after cultivation of 48 hr by the killer toxin from the fusants. The recipient S 29 and Kyokai 7 were found to have neither L nor M dsRNA plasmid. However, K 52 and fusants had both L and M dsRNA plasmid of 4.7 kb and 2.5 kb, respectively. The curants treated by heat and cycloheximide did not contain M dsRNA plasmid, but had large amounts of L dsRNA plasmid of those of killer yeasts.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.634-641
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• 2014

In order to elucidate the ecological and phenological responses of bean under global warming situation, we investigated leafing and flowering phenomena and growth traits of Baktae and Seomoktae in control plot (ambient $CO_2$ concentration and temperature) and warmed plot (elevated $CO_2$ concentration and increased temperature than control) in green house. Average $CO_2$ concentration and temperature were set 540 ppm in treatment and higher $2.2^{\circ}C$ in treatment than control. The appearance of leaf unfolding and the initiation of blooming and fruit maturing in Seomoktae were late in treatment than control. In case of Baktae, the number of total pods and seeds per plant in treatment was fewer than that in control. For Seomoktae, the number of total pods per plant and weight of total seeds per plant were decreased in treatment than in control. Thus, the number of pods and seeds of Baktae declined and the production of Seomoktae was decreased under global warming condition. This result indicates that site selection and crop yield for cultivating of the bean may be changed into new area due to global warming condition.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.98-106
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• 1987

The effect of carbofuran (2, 3-Dihydro-2,2-dimethyl-benzofuran-7-ylmethyl carbamate) on rice growth was evaluated as a direct growth stimulant of rice. For this, several laboratory and field trials conducted from 1981 to 1986 at the Yeongnam Crop Experiment Station. Carbofuran solution affected the germination of rice seed. The growth of seminal roots was adversely affected by the increase of carbofuran concentrations while the length of single root became longer with the concentration increment up to 50 ppm. Carbofuran application (0.18g ai/$m^2$) at the rice nurserybed significantly enhanced the rice growth and recovered from the Low temperature damage. The enhancement effect was more pronounced at the plot that applied carbofuran before rice seeding as soil incorporation than top-dressing. The effect of growth enhancement further extended to transplanted lowland rice. This effect was greater at double cropping area (late of June transplanting) compared to single cropping area (May transplanting). Among important agronomic traits, the increment of panicle number was the most important direct effect for increasing rice grain yield by carbofuran application. Carbofuran application also exhibited the reducing effect against low temperature damage at reductive division stage and at rice heading stage and against submergence damage at booting stage through enhancement of fertile grain ratio, ripening ratio or photosynthetic activity.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.143-150
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• 2009

Deicing salt is used to melt snow and ice on the road for traffic safety during the winter season, which accumulates in the roadside vegetation and induces visible injuries. The damage may accelerate particularly when it coincides with early spring leaf out. In order to better understand the response mechanisms, C. kousa (3-year-old) was irrigated twice prior to leaf bud in a rhizosphere with solutions of 0.5, 1.0, and 3.0% calcium chloride ($CaCl_2$) concentration, that were made by using an industrial $CaCl_2$ reagent practical deicing material in Seoul. Physiological traits of the mature leaves were progressively reduced by $CaCl_2$ treatment, resulting in reductions of total chlorophyll contents, chlorophyll a:b, photosynthetic rate, quantum yield, stomatal conductance, $F_V/F_M$, and NPQ. On the contrary, light compensation point and dark respiration were increased at high $CaCl_2$ concentration. A decrease in intercellular $CO_2$ concentration by stomatal closure first resulted in a reduced photosynthetic rate and then was accompanied by low substance metabolic rates and photochemical damage. Based on the reduction of physiological activities at all treatments ($CaCl_2$ 0.5%, 1.0%, and 3.0%), C. kousa was determined as one of the sensitive species to $CaCl_2$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.246-268
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• 2019

Soybean [Glycine max (L.) Merr.] is a species of legume native to East Asia. The interactions between climatic conditions and genetic characteristics are known to affect the agricultural performance of soybean. Therefore, the present investigation was conducted to identify the main elements affecting the agricultural performances of 11 soybean varieties/lines from China [Harbin ($45^{\circ}12^{\prime}N$), Yanji ($42^{\circ}53^{\prime}N$), Dalian ($39^{\circ}30^{\prime}N$), Qingdao ($36^{\circ}26^{\prime}N$)] and the Republic of Korea [Suwon ($37^{\circ}16^{\prime}N$), and Jeonju ($35^{\circ}49^{\prime}N$)]. The days to flowering (DTF) of soybeans with the e1-nf and e1-as alleles and the E1e2e3e4 genotype, except in 'Keumgangkong', 'Tawonkong', and 'Duyoukong', were relatively short compared to those of soybeans with other alleles. Although DTF of the soybeans was highly correlated with all climatic conditions [negative: precipitation, average temperature (AVT), accumulated temperature; positive: day-length (DL)], days to maturity and 100-seed weight of the soybeans showed no significant correlation with any climatic conditions. The soybeans with a dominant Dt1 allele, except 'Tawonkong', had the longest stem length (STL). Moreover, STL of the soybeans grown in the test fields showed a positive correlation with only DL; however, the results of our chamber test that was conducted to complement the field tests showed that STL of soybean was positively affected by AVT and DL. Although soybean yield (YLD) showed positive correlations with latitude and DL (except L62-667, OT89-5, and OT89-6), the response of YLD to the climatic conditions was cultivar-specific. Our results show that DTF and STL of soybeans grown in six different latitudes are highly affected by DL, and AVT and genetic characteristic also affect DTF and STL.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.345-350
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• 2006

Recently we have interest on rice products developed by environment-friendly management. The technology of paper mulching was practised without herbicide in machine transplanting cultivation of paddy. A field experiment was conducted on Gangseo series (coarse loamy, mixed, nonacid, mesic family of Aquic Fluventic Eutrochrepts) at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Republic of Korea in 2004. This experiment was carried out to evaluate rice growth, weed control and nitrogen efficiency by the different controlled-release fertilizer levels in paper mulching transplanting. Treatments consisted of conventional fertilization, controlled-release fertilizer (100%, 80%, 60%) compared with nitrogen amount ($110kg\;ha^{-1}$) of conventional fertilization and no nitrogen plot. Mulching paper consisted of recycled paper which was coated with biodegradable plastics. There were no differences between conventional rice transplanting and paper mulching on missing hills. Weed occurrence and control were diverse and low as fertilizer amount increased. Plant height and tiller number per hill increased as fertilizer amount decreased. There were no difference between controlled-release fertilizer 80% and conventional fertilization plot on rice growth traits. Leaf color and $NH_4{^+}-N$ in soil had similar trends. There was no difference in yield between controlled-release fertilizer 80% and conventional fertilization plot. Agronomic nitrogen-use efficiency was high as fertilizer amount decreased. Therefore, these results suggested controlled-release fertilizer 80% should be optimum amount under paper mulching transplanting of rice considering weed control, rice growth and nitrogen efficiency.

• Korean Journal of Breeding Science
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• v.43 no.4
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• pp.311-317
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• 2011

This experiment was conducted to give basic information to sprout-soybean breeding and automated sprout production by investigating the effect of seed size on the sprout growth and texture. Twenty cultivars and lines including large and medium soybean, small interspecific cultivars and extra-small wild soybean lines were used. Seeds were cultured for 4 days using small sprout-culturing kits. Hypocotyl length of large Hwanggeumkong, small Pungsannamulkong and Soyoung were longer and wild soybean lines were shorter than other cultivars. Fresh sprout weight and growth rate per unit dry seed weight of wild soybean lines ware increased dramatically and more than other cultivars between 48 to 72 hours after culture. Not only the increasing rate but sprout yield ratio to used dry seed weight showed the negative relationship pattern with seed size. The hardness of hypocotyl in Jangyeubkong, mastication in Taekwang, and cutting force in Eunhakong were the highest as 3,505 g, 1,650 g, and 133 g respectively, and texture values of these traits in wild soybean YWS516 were the lowest. Cutting force of soybean hypocotyl showed the positive relationship pattern with seed size. Breaking force of hypocotyl in large Jangyeobkong was the highest as 83.5g and wild soybean lines were the lowest showing the same pattern as other textural characters.