• Mycobiology
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• v.51 no.6
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• pp.463-467
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• 2023

Soybean is one of the world's most widely cultivated food crops, and soybean seeds are supplied from national seed resources in Korea. However, the transmission of seed-borne diseases through infected soybean seeds is problematic. Among these diseases, soybean seed decay is caused by Diaporthe spp. Infecting the pods, and the infected seeds show rotting symptoms. Most diseased seeds are removed during the selection process; however, it is difficult to distinguish infected seeds that do not display symptoms. Hence, a sequencebased method was devised to screen Diaporthe-infected seeds. Based on the nuclear ribosomal internal transcribe spacer (ITS) region of the pathogen, a primer was designed to distinguish the infection from other soybean seed pathogens. As a result of the comparison between healthy and Diaporthe-diseased seeds by using the primers, Diaporthe was detected only in the diseased seeds. Therefore, it is possible to distribute healthy soybean seeds by detecting Diaporthe-diseased seeds at the genetic level using the Diaporthe-specific primers.

• Mycobiology
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• v.40 no.4
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• pp.265-267
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• 2012

Sleeping blight was observed on soybean plants grown in Yanggu, Suwon and Geumsan from 2005 to 2011. Symptoms developed on stems and pods of affected soybean plants. Five fungal isolates were obtained from the diseased plants and identified as Septogloeum sojae based on their morphological, cultural and molecular characteristics. Pathogenicity of the fungus was confirmed on soybean plants by artificial inoculation. This is the first report of S. sojae causing sleeping blight in soybean plants in Korea.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.526-530
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• 1998

The effect of field sanitation using ecological characters of the pathogen was investigated for controlling Phomopsis seed decay in soybean. Field sanitation which was eliminated the inoculum by removing host debris, abscised petioles and cotyledones out of field, reduced remarkably infection percentage of pods and seeds by Phomopsis spp. as compared to the inoculated field. Neverthless, seed infection was 28.7% in the sanitized field. The fields sanitized by benlate application around the soybean plants also decreased seed infection with Phomopsis spp. Total seed infection including that with miscellaneous pathogens occurred as much as 75∼79% to the no application and their control values were 34∼42% over the routine application schedule. Even though it was not satisfactory, field sanitation seemed to be effective in controlling Phomopsis seed decay when infection pressure was low level. Diaporthe phseolorum va. sojae, D. phaseolorum var. caulivora and Phomopsis longicolla were mostly identified from soybean seeds and Colletotrichum truncatum, Cercospora kikuchiana were also isolated in sequence. Field sanitation did not significantly increase in soybean yield over the no application, while routine application schedule did in field.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.331-336
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• 2004

Changes in the level of metabolites in leaves and pods were examined with respect to the seed chemical composition in black soybean. There was no further increase in pod length after 42 days after flowering (DAF). Pod weight, however, persistently increase until 73 DAF, thereafter the weight was slightly lowered. The seed storage protein, however, increased drastically as the increasing rate of pod weight was lessened at 61 DAF. The accumulation of seed storage proteins was occurred conspicuously as the increasing rate of pod weight was slowed down. The chlorophyll content both in leaves and pods was drastically decreased after 50 DAF. The beginning of drastic reduction in chlorophyll content was occurred concomitantly with the reduction of soluble protein content in leaves. The sugar content in leaves showed similar tendency with chlorophyll and soluble protein content. The starch level in leaves, however, showed different changing pattern during seed development. The starch content in leaves was increased persistently until 66 DAF, thereafter the content was decreased drastically to about $55\%$ of maximal value at 66 DAF. Total phenolics content in leaves and the anthocyanins content in seeds were stable without noticeable increase until 66 DAF. The contents were increased dramatically after 66 DAF showing the synchronized pattern with the decrease in starch level in leaves. The levels of the selected metabolites in leaf and seed suggested that the accumulation of chemical components of black soybean seed is launched actively at 66 DAF. The profile of storage proteins was nearly completed at 61 DAF because there was no large difference in densitometric intensity among protein subunits after 61 DAF. In soybean, chemical maturation of seed begins around 61 to 66 DAF at which most metabolites in vegetative parts are decreased and remobilized into maturing seeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.131-135
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• 2004

To find out the responses of soybean genotypes in terms of different levels of irrigation with the aim of evaluating the growth, yield, and its optimum levels of irrigation, an experiment was conducted at the Field of Crop Botany Department, Bangladesh Agricultural University, Mymensingh during the period from November 2000 to February 2001. Five levels of irrigation viz. $\textrm{I}_0$: no irrigation, $\textrm{I}_1$: one time irrigation at 20 days after sowing (DAS), $\textrm{I}_2$:two times irrigation at 20 and 40 DAS, $\textrm{I}_3$: three times irrigation at 20, 40, and 60 DAS, and $\textrm{I}_4$: four times irrigation at 20, 40, 60, and 80 DAS and three genotypes of soybean viz. BS-3, BS-16, and BS-60 were used in this experiment. The crop was grown in a split plot design having three replications. The plant height, leaf area index, crop growth rate, shoot dry weight, branches $\textrm{plantI}_{-1}$, filled pods $\textrm{plantI}_{-1}$, seeds $\textrm{plantI}_{-1}$, seed yield, and harvest index were influenced significantly by irrigation and these were found to be highest at three times irrigation except branches $\textrm{plantI}_{-1}$. The chlorophyll content increased but empty pods $\textrm{plantI}_{-1}$ decreased with increase in irrigation levels. Genotypes of soybean varied significantly in terms of growth attributes at various growth stages except shoot dry weight at 90 DAS. The genotype BS-3 performed better compared to other genotypes and gave maximum seed yield.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.221-221
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• 2017

This experiment was performed to analyze variation of growth traits of soybean to determine the information of less sensitive traits under different environmental conditions. Sowing was carried out on June 2 each year and the experimental plot was laid out in three replicates by randomized complete block design with thirty soybean varieties which consisted of 19 cultivars for beancurd and soypaste, 8 cultivars for soy-sprout including 1 landrace, and 3 cultivars for cooking with rice including 1 landrace during the period 2014-2015. The weather conditions during the experimental period were quite different with extremely low precipitation and longer sunshine duration in 2015 than 2014. The variation of characteristics related to growth period such as days of growth, days of maturity, days of flowering and the 100-seed weight was less in spite of different environmental conditions. While the variation of the number of pods per plant was high. Considering growth and seed characteristics like the number of pods per plant, the number of seeds per pod and 100-seed weight which are linked directly to the yield, cultivars such as Shingi, Daewonkong, Danbaegkong, and Daepung for beancurd and soypaste, Pungwon, Haepum and Shingang for soy-sprout and Seoritae for cooking with rice were more stable and could be expected to have high yield in Suwon, the south-central part of South Korea. These results could be useful for the selection of breeding resources to develop cultivars with high stability under changeable weather condition.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.406-408
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• 2005

Web blight symptoms were frequently observed on soybean plants grown in a farmer's fields located in Jincheon in Korea during a disease survey in August, 2005. Incidence of the disease was $5-20\%$ infected plants in two of four soybean fields investigated. A total of 31 isolates of Rhizoctonia sp. were obtained from leaves, leaf petioles, and pods of diseased soybean plants. The isolates were identified as Rhizoctonia solani AG-l(IA) by anastomosis test and based on the morphological and cultural characteristics. Three isolates of R. solani AG-l(IA) were tested for pathogenicity to five cultivars of soybean by artificial inoculation. All the isolates induced blight symptoms on the leaves of soybean and formed sclerotia on the lesions, which were similar to those observed in the field. The pathogenicity tests revealed that all the soybean cultivars tested were susceptible to the pathogen. There was no difference in the pathogenicity among the isolates. The present study first reveals that R. solani AG-l(IA) causes web blight of soybean in Korea.

• The Korean Journal of Mycology
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• v.11 no.2
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• pp.99-101
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• 1983

Black root rot caused by Cylindrocladium crotalariae is one of the most serious soilborne disease in soybean. Plant height reduction of Hwangkeum Kong was 38% by the rotting of the whole main root and 9% by rotting of the half of the main root as compared with partial discoloration in the main root. Pod number per plant and seed weight were significantly reduced by the increase of the disease severity. Important yield components such as number of pods per plant and seed weight were negatively correlated with the soybean black root rot severity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.8 no.1
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• pp.1-4
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• 1970

To study the varital response of grain, protein and oil yield to different sowing dates and calcium levels in soybean, the most important crop as a protein source in Korea, this experiment was conducted in 1969. Three leading soybean varieties (Choongbukbaek, Ryooku＃3 and Changdanbaekmok) were sown at May 22,, June 11 and July 1 under 3 different calcium levels, 0.50 and 100kg per 10a respectively. The results are summarized as follows: 1. Ryonku ＃3 showed the highest grain yield because of the highest number of pods per hill. In order of protein content, and oil content of grain, Choongbukbaek>Ryooku＃3>Changdanbaekmok and Changdanbaekmok>Choogbukbaek>Ryooku＃3 were found. Ryooku＃3 also showed the highest protein and oil production per unit area owing to the highest grain yield. However. varietal differences of the grain yield the protein and the oil production per unit area varied along the different sowing dates. Interactions between varieties and sowing date on the grain yield should be considered in practice. 2. No difference in the grain yield was found between the first sowing date (May22) and the second (June11) on average. The grain yield in the plot of the third sowing date (July l)was strikingly decreased mainly by the smaller number of pods per hill. The protein and the oil content were not varied significantly by the different sowing dates. The protein and oil production per unit area were lowest in the plot of the third sowing date owing to the decreased grain yield. 3. More calcium application increased the number of branches per hill, the number of pods per hill, and the grain yield. The highest grain yield was found in the plot received 100 kg of calcium hydroxide per 10are. Protein content increased in higher calcium level, but oil content was highest in the plot of noncalcium. More protein production per unit area was gotten by more calcium application because of higher grain yield and protein content. all production increased in higher calcium level by the increased grain yield. 4. High plus (+) correlation was found between stem length and stem weight per hill stem length and grain weight, stem length and grain yield, stem weight per hill and number of pods per hill and grain weight, number of branches per hill and grain weight, number of pods per hill and grain yield, and grain weight and protein content of grain. Minus(-) correlation was recognized between number of pods per hill and grain weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.86-94
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• 1996

This experiment was carried out to investigate the differences of the growth and yield characteristics at different planting dates in two soybean ecotypes from 1993 to 1994. Two summer types of soybean varieties, Suwon 163 and CNS 342, and two autumn types, Hwangkumkong and Keomcheongkong ＃1 were planted 7 times from 22 April to 21 June with 10 days interval in 1993 and 4 times from 22 April to 21 June with 20 days interval in 1994 at experimental field, Dankook University, Cheonan. Emergence rate was shown to difference between the summer types and the autumn types, as planting date delayed and between 1993 and 1994. The average emergence period was more shortened in 1994 than 1993. This was reduced as planting date delayed. Days to flowering, pod formation and maturity were shortened as planting date delayed, and observed that shortening of days to flowering and maturity were smaller in the summer types than the autumn types. Stem height, stem diameter, number of mainstem nodes, number of branches and number of branch nodes were different between the summer types and the autumn types and between 1993 and 1994. These were reduced as planting date delayed. The number of pods per plant was also different between 1993 and 1994, and reduced as planting date delayed. The number of seeds per pod was not different between 1993 and 1994, and shown to similar tendency as planting date delayed. It was observed that one hundred seed weight of the summer types were reduced, but the autumn types were not as planted date delayed in 1993. In 1994, one hundred seed weight was not measured because almost all pods were unfilled or shriveled probably due to high temperature during pod formation period. The rate of unfilled pods per plant was higher the autumn types than in the summer type of soybeans in 1994.