• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.269-276
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• 2019

A semi-greenhouse experiment with field grown soybean (Glycine max L. cv Deawon, Uram, Jinpong, Soyon, Pungsangnamul, and Haewon) was performed in 2018. The experiment was aimed to investigate individual impacts of drought stress on soybean characteristic and seed yield. The three treatments were used in non-water stress (Control) during the soybean growth season, vegetative stage stress (VS), and flowering period stress (FS). Leaf number, LAI, leaf nitrogen concentration, and leaf biomass were decreased by drought at R4. In our study, the number of pods was 33.6% and 40.5% lower, respectively, in control than in VS and FS. In 100 seed weight, was 16.1% and 10.1% lower, respectively, in control than in VS and FS at R8. As a result, seed yield was 39.8% and 45.1% lower, respectively, in control than in VS and FS. Depending on the drought period, Daewon and Haewon showed a large decrease in yield, while Soyon did not change. The results of this study showed that flower and beginning pod setting stage responded more sensitively to the drought period than vegetative stage. Overall, these results demonstrate soybean seed yield formation more sensitive the during the flowing and beginning pod setting stage. We conclude that adequate water supply for pod setting stage, guaranteeing a high seed yield.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.101-101
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• 2022

In recent years, due to climate change, the livestock industry has become more interested in the production of forage crops. In Korea, more than 74% of forage crops are cultivated in winter rice fields. In particular, Italian ryegrass (IRG) is depends on imports for more than 70% of its seeds. In generally, the IRG rapeseed cultivation method involves sowing from early October to mid-October by drill sowing seeding or spot seedling. However, the sowing period is delayed due to frequent rainfall during. And, same period require a lot of seeds. However, raising seedlings and transplanted IRG will overcome weather conditions and reduce the amount of seeds. This study was intended to be applied to the domestic IRG seed industry in the future through growth and quantity evaluation according to transplant time and planting density for the production of good quality IRG seeds in rice paddy fields. In this study, transplanting time (October 20, October 30, November 10) and planting density (50, 70, and 80) were cultivated at the National Institute of Crop Science in 2021. The amount of fertilizer applied was adjusted to (N-P₂O₅-K₂O) 4.5-12-12 (kg/10a), and then 2.2(kg/10a) of nitrogen was added each year. For the growth survey, leaf area, canopy coverage, plant length, and seed yield were investigated. Along with the transplanting time, the plant length was higher on October 20 than on October 30 and November 10. On the other hand, leaf area index changes differed depending on the transplanting time and planting density, and were particularly high on October 20, 80 density and 70 density, but similar on October 30 and November 10. 1000 seed weight showed no difference with transplanting time and planting density. On the other hand, the seed yield was 215(kg/10a) for 80 density on October 20, 211(kg/10a) for 70 density, 118(kg/10a) for 50 density, and 80 density for October 30 and November 10. and 70 density did not differ. On the other hand, the 50 density on October 30 and November 10 were 164(kg/10a) and 147(kg/10a) respectively. As can be seen from this study, the earlier the transplant, the higher the seed yield. However, the 50 density was reduced in yield compared to the 70 density and 80 density.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.495-501
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• 2006

This study was conducted to investigate the effects of thinning on soil properties and seed productivity in the 25-year-old Cryptomeria japonica and 30-year-old Chamaecyparis obtusa seed orchards in which thinning had been performed 4 years prior to the study. To this end, soil properties, cone and seed characteristics, seed production (kg/ha), and nutrient contents in seeds and cones were studied by 4 different thinning intensities (0, 20, 40, and 60%). Soil properties were not significantly different between the two orchards. Meanwhile, electric conductivity, total nitrogen, and $K^+$ concentration in the soil of C. obtusa seed orchard were significantly different among 4 different thinning intensities (p<0.05), while only $Ca^{2+}$ concentration in the C. japonica seed orchard was different (p<0.05). In the C. obtusa seed orchard, cone productivity increased with the increase of thinning intensities (p<0.05), whereas that in the C. japonica seed orchard did not show any significant differences. Both of the two seed orchards showed a tendency that seeds become bigger and heavier with the increase of thinning intensities, but any significant differences were not found. Seed production (kg/ha) in the C. obtusa seed orchard significantly increased with the increase of thinning intensities, while that of the C. japonica seed orchard decreased. Nutrient contents in seeds and cones did not show any significant differences among different thinning intensities in both of the two seed orchards.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.381-388
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• 2004

In Korea, production of super sweet corn has been economically feasible and is substituting for traditional sweet corn due to better flavor in recent years. Major limiting factors for super sweet corn production are low field emergence and low seedling vigor. The optimum water potential (WP) for the priming of normal and aged seeds of dent, sweet (su) and super sweet (sh2) corns was studied to improve low seed quality. Seeds were primed at 0, -0.3, -0.6, -0.9, and -1.2 MPa of polyethylene glycol (PEG) 8000 solution at $15^{\circ}C$ for 2 days. Priming effects differed depending on the type of corn, seed quality, and WP of PEG solution. Although WP of priming solution did not influence the emergence rate of extremely high quality normal dent corn seeds, it reduced time to $50\%$ emergence (T50) and increased plumule weight. In contrast, the emergence rate of aged field corn was improved by seed priming at 0 MPa and plumule weight and $\alpha-amylase$ activity was enhanced. The optimum WP for both normal and aged sweet and super sweet corn seeds was between -0.3 and -0.6 Mpa. At the optimum WP emergence rate, $\alpha-amylase$ activity, and content of DNA and soluble protein increased, while T50 and leakage of total sugars and electrolytes reduced.

• International Journal of Oral Biology
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• v.43 no.1
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• pp.37-42
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• 2018

It is noted that Streptococcus mutans (S. mutans) triggers dental caries establishment by two major factors: the synthesis of organic acids, which demineralize dental enamel, and the synthesis of glucans, which mediate the attachment of bacteria to the tooth surface. Therefore, it is noted that the development of a more effective, substantial and safe preventive agent that works against dental caries and periodontal disease is required at this time. For this reason, the present study was designed to investigate the effect of croton seed ethanol extracts on the growth, acid production, adhesion, and insoluble glucan synthesis of S. mutans. In this case, the ethanol extract of croton seed showed concentration dependent inhibitory activity against the growth, acid production and adhesion of S. mutans. Especially, it is important to note that it has produced significant inhibition at the concentration of 0.1 and 0.2 mg/ml as compared to the control group. Moreover, these results suggest that the application of croton seed extract may be considered to be a useful method for the prevention of dental caries.

• Journal of Forest and Environmental Science
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• v.38 no.1
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• pp.12-20
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• 2022

Pongamia (Pongamia pinnata L.) as a source of non-edible oil, is potential tree species for biodiesel production. For several reasons, both technical and economical, the potential of P. pinnata is far from being realized. The exploitation of genetic diversity for crop improvement has been the major driving force for the exploration and ex situ/in situ conservation of plant genetic resources. However, P. pinnata improvement for high oil and seed production is not achieved because of unsystematic way of tree improvement. Performance of P. pinnata planted by Karnataka Forest Department was assessed based on yield potential by collecting 157 clones out of 264 clones established by Karnataka Forest Department research wing under different research circles/ranges. It was evident that the all the seed and pod traits were significantly different. Further, selection of superior germplasm based on oil and pod/seed parameters was achieved by application of Mahalanobis statistics and Tocher's technique. On the basis of D² values for all possible 253 pairs of populations the 157 genotypes were grouped into 28 clusters. The clustering pattern showed that geographical diversity is not necessarily related to genetic diversity. Cluster means indicated a wide range of variation for all the pod and seed traits. The best cluster having total oil content of more than 34.9% with 100 seed weight of above 125 g viz. Cluster I, II, III, IX, XV, XIX, XXI, XXIII, XXVI and XXVII were selected for clonal propagation.

• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.222-227
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• 1994

Effects of field applications of benomyl on Phomopsis seed decay of early soybeans were investigated at Suwon in 1992 and 1993. Pod and immature seed infections were markedly suppressed by benomyl application at the R6 stage whereas the spray at the R7 stage was not as effective as the spray at R6. When compared with unsprayed plots, benomyl spray at R6 resulted in decrease in Phomopsis seed infection by 37.1% and 73.9%, and increased in frequency of seed germination by 1.8% and 8.0% in 1992 and 1993, respectively. The results indicated that only one spray at early R6 could effectively reduce seed infection by Phomopsis spp.and could be adopted in a disease management program for commercial production of healthy soybean seeds.

• The Korean Journal of Mycology
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• v.21 no.4
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• pp.316-322
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• 1993

Examination by scanning electron microscopy and potato-dextrose agar medium showed that the dry seeds of R. raetam were externally free of fungi. When planted in sandy loam soil, the seeds become colonized with eleven soilborne fungal species. The fungi were isolated on cellulose agar, pectin agar and lignin agar media. Aspergillus flavus, A. niger, Penicillium capsulatum and Fusarium oxysporum had broad occurrence and recovered on the three media. The production of hydrolytic enzymes by the isolated fungi depends on the substrate and species. P. capsulatum, P. spinulosum and A. niger had wide enzymatic amplitude and they were able to produce cellulolytic, pectolytic and lignolytic activities on corresponding substrates as well as on seed coat containing media. The lignolytic activities of the isolated species except Chaetomium bostrychods and Trichoderma viride were enhanced on applying the seed coat materials as C-source rather than using lignin. Soaking R. raetam seeds in culture filtrates of the most fungi grown on seed coat supplemented media induced pronounced and distinct stimulating effect on seed germination. The most effective filtrates were those of P. capsulatum, P. spinulosum and Sporotrichum pulverulentum.

• Plant Resources
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• v.7 no.3
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• pp.233-237
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• 2004

This study was conducted to develop effective production system in greenhouse for leaves and stems of Angelica acutiloba by using connect pots in 2003 and 2004. Seed germination rate and plant biomass of Angelica acutiloba collected in 2004 were higher than those harvested in 2003. Germination rate of Angelica acutiloba seeds collected in 2003 was 10％, while germination rate of seeds collected in 2004 was above 90％. Especially, plant growth and yield of Angelica acutiloba grown in connect pots sized with 4 ${\times}$ 4 ${\times}$ 5cm(length ${\times}$ width ${\times}$ height) were the highest. These results indicate that leaf and stem production of Angelica acutiloba can be improved by using connect pots and optimizing seed collecting time in greenhouse.

• Proceedings of the Korean Society of Crop Science Conference
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• 1988.02a
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• pp.46-47
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• 1988