• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.1
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• pp.38-43
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• 2003

Immature and mature embryos of 18 Korean wheat genotypes were cultured in vitro to develop an efficient method of callus formation and plant regeneration, and to compare the responses of both embryo cultures. Immature and mature embryos were placed on a solid agar medium containing the MS salts and vitamins, 30g/l maltose, 2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), and amino acids. The developed calli were maintained on regeneration medium containing MS salts and B5 vitamins, 20 g/l sucrose, and the combination of two plant growth regulators, 6-benzylaminopurine (BAP) and indole-3-acetic acid (IAA). Immature embryos in most genotypes showed high efficiency of callus induction except three genotypes; Eunpamil, Chunggemil, and Namhaemil, and significant differences among the genotypes. Plant regeneration of calli induced from immature embryos showed high efficiency in Geurumil (56.5%), Tapdongmil (50.5%), Gobunmil (45.5%), and Urimil(42.2%). The analysis of variance showed significant differences for regeneration frequency among the genotypes. Mature embryos showed low callus induction frequency compared with that in immature embryos, and significant differences among the genotypes. Plant regeneration of calli induced from mature embryos showed high efficiency in Keumkangmil (33.33%), Tapdongmil(28.13%), and Geurumil (27.78%). The analysis of variance showed significant differences for plant regeneration frequency among the genotypes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.183-188
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• 1993

This experiment was conducted to investigate the effect of sulfur containing fertilizers on growth, yield and nutritive quality of soybean as affected by lime application at reclaimed soil. Lime application for neutralization requirements showed the effect of increased grain yield about 32% compared to the non application at newly opened land of red and yellow soil. In case of lime application, the sulfur containing fertilizers combined with super phosphate, ammonium sulfate, and gypsum increased the grain yield by 31%, 11%, and 3%, respectively. When lime was not applied, magnesium carbonate application increased the yield by 47%, super phosphate by 22%, and gypsum by 15%. The protein content of grain was higher at lime application than those of non lime application and was increased by the application of sulfur containing fertilizer. But lipid content was not affected by lime or sulfur application. From the above results obtained it was concluded that sulfur fertilizer effect under lime application was significant when combined with super phosphate or ammonium sulfate application. Magnesium carbonate or super phosphate application was the best combination with sulfur-containing fertilizer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.311-322
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• 2019

In order to establish an optimal double cropping system to obtain the maximum annual quantity, we investigated the annual productivity of whole-crop silage (WCS) rice, Jowoo (Jw), Yeongwoo (Yw), and Mogwoo (Mw), and winter feed crops (WFC), Italian ryegrass (IRG), Greenfarm (GF), rye Gogu (GU), and triticale Joseong (JS), in paddy fields of the central plains of Korea. From 2016 to 2019, each crop was subjected to two standard cultivation methods: WCS rice and WFC optimal. Using the WCS optimal mode, the average dry matter yield (DMY) of WCS rice, early flowering Jw, was 15.8 tons/ha and 21.0 for the mid-late heading Yw; there was no significant difference compared to the 19.2 tons/ha late-flowering Mw (p<0.01). The WFC were not significantly different between GF (3.2 tons/ha) and GU (4.5) sown on September 23rd, while JS was the highest at 12.6 tons/ha (p<0.001). There was a significant difference in the order of JS (16.6 tons/ha) > GF (10.5) > GU (4.7)(p<0.001) sown on October 11th. For JS sown on October 31st, the DMY was 11.8 tons/ha, which was significantly higher than that of the other two crops (p<0.05). Except for rye GU, DMY was the highest when sown on October 11th. For WFC optimal mode, the average DMY of JS was the highest at 18.3 tons/ha, which was significantly different from that of GF (10.9) and GU (9.6) (p<0.001). The DMY of WCS rice transplanted on May 10th was the highest at 23.0 tons/ha in Mw, which was not significantly different from that of Yw (21.4) but significantly different from that of Jw (15.9) (p<0.05). On transplanting on May 25th, the DMY of Mw was the highest at 24.2 tons/ha; this was not significantly different from that of Yw (20.7), but it was significantly different from that of Jw (18.6) (p<0.05). When transplanted on June 11th, the DMY was 21.3 tons/ha in Yw, which was significantly higher than the DMY of other two cultivars, Jw and Mw (p<0.05). For the WCS rice-WFC double cropping, the total annual DMY was 33.6 tons/ha with the combination of the WCS rice, Yw, and the triticale JS for WCS optimal mode. Meanwhile, the total annual DMY was 39.6 tons/ha with the combination of the triticale JS and the WCS rice, Yw, for WFC optimal mode. In conclusion, the strategies for obtaining the maximum yield of high-quality forage for WCS rice-WFC, WFC-WCS rice double cropping are as follows: 1) cultivation centered on the optimal mode of WFC, and 2) sowing the WFC, triticale JS in mid-October, harvesting the crops around the end of May and transplanting the WCS rice, Yw, in early June to obtain the maximum DMY of 39.6 tons/ha.

• Korean Journal of Remote Sensing
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• v.35 no.6_3
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• pp.1273-1283
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• 2019

This paper proposes an advanced crop classification model that combines a procedure for weighted combination of spatial features extracted from multi-scale input images with a conventional convolutional neural network (CNN) structure. The proposed model first extracts spatial features from patches with different sizes in convolution layers, and then assigns different weights to the extracted spatial features by considering feature-specific importance using squeeze-and-excitation block sets. The novelty of the model lies in its ability to extract spatial features useful for classification and account for their relative importance. A case study of crop classification with multi-temporal Landsat-8 OLI images in Illinois, USA was carried out to evaluate the classification performance of the proposed model. The impact of patch sizes on crop classification was first assessed in a single-patch model to find useful patch sizes. The classification performance of the proposed model was then compared with those of conventional two CNN models including the single-patch model and a multi-patch model without considering feature-specific weights. From the results of comparison experiments, the proposed model could alleviate misclassification patterns by considering the spatial characteristics of different crops in the study area, achieving the best classification accuracy compared to the other models. Based on the case study results, the proposed model, which can account for the relative importance of spatial features, would be effectively applied to classification of objects with different spatial characteristics, as well as crops.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.182-187
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• 2012

Objective of this research was to evaluate the effects of different organic matter on growth and yield in rice plants and suppression of weed occurrence in paddy soil. The treatments consisted of rice bran, expeller cake, or combination of rye green manure and rice bran without any agrochemical or fertilizer. At 50 days after transplanting (DAT), plant height of rice between conventional practice and expeller cake treatments were similar, while rice bran treatment was inhibited growth of rice during growing period. Also, heading date of rice among the all treatments was not significantly different. Rice yield in expeller cake or rye green manure and rice bran treatments was attained to 91% and 98% of the conventional practice, respectively, while the value in rice bran treatments was just 82%. On the other hand, at 40 DAT of rice plants, occurred major weed species in organic matter treatments were four species, while those in conventional practice were two species. Additionally, the dry weight of weeds in rice bran treatment was significantly inhibited compared to it of expeller cake or combination of rye green manure and rice bran treatments, while the value in rice bran treatment was higher than the conventional practice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.80-84
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• 2002

In spite of simple and cheap cultivation method, water broadcast-seeded rice demonstrates uneven and unstable seedling establishment per unit land area and requires more herbicide and labor-input for weed control. Three experiments were conducted in a phytotron at 18$^{\circ}C$ to evaluate the adaptability of seed-mat mulching cultivation technologies in water seeded rice for the uniform seedling establishment and the inhibition of weed occurrence without herbicide application. Five different kinds of mat with different mesh sizes and fabric properties were tested. The emergence of rice was the highest in Lawn-mat treatment, being comparable with the control, in which seeds were sown without mat. The Lawn-mat also exhibited the lowest mat tension. Mat tension may influence the emergence of rice. And once it was soaked in water, it didn't maintain its original shape any more. The emergence rate of rice was the lowest in Safer-mat treatment. In Lawn-mat treatment, which was the most effective for rice emergence in the first study, the differences of emergence and seedling establishment of rice depending on the seeding position (upper, beneath, and between mats) treatments were negligible, while they were higher in dry seeds than in pre-germinated seeds treatment. The emergence as affected by the kinds of mat also showed the same trend when tested using barnyard grass. Depending on the kinds of mat, the inhibition effect of weeds was the greatest in Safer-mat and the poorest in Lawn-mat. These results strongly suggest the possibility that the uniform seedling establishment and weed management without chemical could be achieved simultaneously by seed-mat mulching through the combination of effective mat for the emergence of rice and another efficient mat for the inhibition of weed occurrence. This possibility was also tested in the field.

• Journal of Korean Society of Rural Planning
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• v.28 no.1
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• pp.57-69
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• 2022

Crop classification is very important for estimating crop yield and figuring out accurate cultivation area. The purpose of this study is to classify crops harvested in fall in Idam-ri, Goesan-gun, Chungcheongbuk-do by using unmanned aerial vehicle (UAV) images and support vector machine (SVM) model. The study proceeded in the order of image acquisition, variable extraction, model building, and evaluation. First, RGB and multispectral image were acquired on September 13, 2021. Independent variables which were applied to Farm-Map, consisted gray level co-occurrence matrix (GLCM)-based texture characteristics by using RGB images, and multispectral reflectance data. The crop classification model was built using texture characteristics and reflectance data, and finally, accuracy evaluation was performed using the error matrix. As a result of the study, the classification model consisted of four types to compare the classification accuracy according to the combination of independent variables. The result of four types of model analysis, recursive feature elimination (RFE) model showed the highest accuracy with an overall accuracy (OA) of 88.64%, Kappa coefficient of 0.84. UAV-based RGB and multispectral images effectively classified cabbage, rice and soybean when the SVM model was applied. The results of this study provided capacity usefully in classifying crops using single-period images. These technologies are expected to improve the accuracy and efficiency of crop cultivation area surveys by supplementing additional data learning, and to provide basic data for estimating crop yields.

• Toxicological Research
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• v.26 no.2
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• pp.109-115
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• 2010

The purpose of this study was to elucidate the mechanism underlying enhanced radiosensitivity to $^{60}Co\;{\gamma}$-irradiation in human prostate PC-3 cells pretreated with berberine. The cytotoxic effect of the combination of berberine and irradiation was superior to that of berberine or irradiation alone. Cell death and Apoptosis increased significantly with the combination of berberine and irradiation. Additionally, ROS generation was elevated by berberine with or without irradiation. The antioxidant NAC inhibited berberine and radiation-induced cell death. Bax, caspase-3, p53, p38, and JNK activation increased, but activation of Bcl-2, ERK, and HO-1 decreased with berberine treatment with or without irradiation. Berberine inhibited the anti-apoptotic signal pathway involving the activation of the HO-1/NF-${\kappa}B$-mediated survival pathway, which prevents radiation-induced cell death. Our data demonstrate that berberine inhibited the radioresistant effects and enhanced the radiosensitivity effects in human prostate cancer cells via the MAPK/caspase-3 and ROS pathways.

• Korean Journal of Remote Sensing
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• v.30 no.4
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• pp.493-503
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• 2014

A hierarchical classification scheme, which can reduce the spectral ambiguity and also reflect crop cultivation patterns from past land-cover maps, is presented for the purpose of the early production of crop classification maps in large-scale crop areas. Specifically, the effects of mixed pixels are minimized not only by applying a hierarchical classification approach based on different spectral characteristics from crop growth cycles, but also by considering temporal contextual information derived from past crop cultivation patterns. The applicability of the presented classification scheme was evaluated by a case study of Iowa State in USA with time-series MODIS 250 m Normalized Difference Vegetation Index(NDVI) data sets and past Cropland Data Layers(CDLs). Corn and soybean, which are major crop types in the study area and also display spectral similarity, could be properly classified by applying different classification stages and accounting for past crop cultivation patterns. The classification result by the presented scheme showed increases of minimum 7.68%p and maximum 20.96%p in overall accuracy, compared with one based on purely spectral information. In addition, the combination of temporal contextual information during classification was less affected by the number of NDVI data sets and the best overall accuracy of 86.63% was achieved. Thus, it is expected that this classification scheme can be effectively used for the early production of large-area crop classification maps in major feed-grain importing countries.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.1
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• pp.123-127
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• 2012

An experiment was carried out to boost the production of tasar crops through application of secondary nutrients. Different combinations of secondary nutrients were prepared and its effect was studied on the yield and quality of leaves of tasar food plant Terminalia tomentosa W & A with 2.4 m ${\times}$ 2.4 m spacing and cocoon characters of tasar silkworm Antheraea mylitta Drury reared on them. Among different combinations of secondary nutrients, foliar application of magnesium sulphate (2%, w/v) and basal application of 3 quintal/ha of calcium carbonate (secondary nutrient combination SM5) was found to be the best in crop improvement. It improves the quantity and quality of leaves as well as the commercial characters of cocoons. As a result, silk production improves. Under this combination, leaf yield increased by 26.55% in comparison to control. Average increase in moisture, total mineral, crude protein and total carbohydrate was 3.26%, 20.84%, 15.39% and 17.85% respectively as compared with control. Further, bio assay studies revealed that average larval weight, E.R.R., cocoon weight, shell weight and silk ratio percent increased by 11.25%, 25.71%, 20.05%, 35.14% and 12.17% respectively over control which indicates that secondary nutrient combination $SM_5$ has significant role in improving the production of tasar crops.