• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.183-189
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• 2023

It is widely known that forage corn is one of the most important crops in the production of silage and green chops during the summer months. In this study, the characteristics and the productivity of Kwangpyeongok, AGR 41, and Nero IT corn cultivars were evaluated in the regions of Jeju and Cheonan, Korea between 2021 and 2022. In each year, different corn cultivars were sown in different parts of the country on April 7 in Jeju and May 3 in Cheonan. The yield of three cultivars, Kwangpyeongok, AGR 41, and Nero IT were measured at the yellow-ripening stage, including the leaves and stems (Stover) and corn grain. Kwangpyeongok stover and total dry matter (DM) yields were slightly higher in Cheonan than in Jeju over the past two years. The quantity of corn cultivated in all cultivated areas was similar. The average yield of AGR 41, corn quantity and total DM were slightly higher in Jeju than in Cheonan. In terms of stover yield, and total dry matter content of the Nero IT cultivar cultivated in Jeju had a slightly higher yield than the cultivar cultivated in Cheonan. Based on this study, all cultivars can show some variations but not too much in terms of growth productivity and distinct characteristics depending on their location. Overall, AGR 41, and Nero IT cultivars in Jeju exhibit slightly higher levels of productivity than the same cultivars in Cheonan.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.3
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• pp.179-184
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• 2024

Corn is essential for both humans and animals. The crop is the third most important food crop after rice and wheat. A rise in farming is resulting in a lack of self-sufficiency of high quality forages. Therefore, corn cultivars in Korea must be optimized to increase productivity and yield. A study was conducted in Pyeongchang, South Korea between 2021-2022 to evaluate the characteristics and productivity of three corn cultivars: Kwangpyeongok, AGR 41, and Nero IT. Different varieties of corn were sown in Pyeongchang on April 29 and April 27 of 2021 and 2022, respectively. The productivity and characteristics of the cultivars Kwangpyeongok, AGR 41, and Nero IT were evaluated during the yellowing ripening stage. The characteristics included the leaves, stems, grain, and stover content. Across different corn cultivars, there was no significant difference in stem height, diameter, forage or grain quantity based on an average of two years. Yet, significant differences were noted in the stem heights of all cultivars between 2021 and 2022 (p<0.05). There was a significant difference in the diameters of Kwangpyeongok and Nero IT between 2021 and 2022. A significant difference in forage yield was observed for Nero IT between 2021 and 2022. The yield of grains and forages was higher in 2021 than in 2022, which could be attributed to temperature and precipitation variations. We can conclude from these data that all cultivars in Pyeongchang showed significant productivity and yield, which could be useful to produce nutrient rich silage for livestock.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.418-424
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• 1998

The production of 8-ketotrichothecenes, deoxynivalenol (DON), nivalenol (NIV), and their monoacetyl derivatives was studied in rice and corn cultures using 8 isolates of Fusarium graminearum which were obtained from corn and barley samples. Higher concentrations of trichothecenes were produced on rice than corn, and production of the toxins on rice was enhanced by growing the fungi at $25^{\circ}C$. The isolates were used for evaluation of toxin production and pathogenicity after artificial inoculation to 5 corn and 3 barley cultivars. The kinds and the relative amounts of trichothecenes produced in cultures were consistent with those in infected kernels of corn and barley with some exceptions. As for DON chemotypes, the ratios of 15-acetyl-DON to 3-acetyl-DON were varied among the pathogen-cultivar interactions. The corn and barley cultivars showed the significant differences of resistance to the Fusarium isolates in disease severity and seedling blight, and resistance ranking to the different isolates was varied. However, significant correlations were observed between the total concentrations of trichothecenes in infected kernels of corn and barley and pathogenicities of the Fusarium isolates to the hosts.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.3
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• pp.265-276
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• 1997

This study was investigated the herbage productivity and nutrient contents of corn (Suweon 19 and Kwanganok) and sweet sorghum (Ramiki sorgo and Silage sorgo) at the stage of maturity (10-DBS, silking, milky and dough stages) to identify the utility value of sweet sorghum as a substituting crop for corn. The silage materials (dough stage) were chopped and were storaged for 90 days in polyethlene bag with O.lmm thickness. Chemical composition, nitrogen content and in vitm dry matter digestibility were evaluated. Also, daily intake and palatability were checked in the feeding trial with four male sheep in average weight about 57kg. Both fresh and dry matter yield of corn and sweet sorghum were increased as the maturity processed (P< 0.05), and sweet sorghum showed higher total yield potential than corn. Crude protein content of the cultivars was decreased as the maturity was processed (P< 0.05). Neutral detergent fiber (NDF) content of the cultivars, in general, showed highest at silking stage, followed by 10 days before silking (10-DBS), and milky and dough stages (Pi0.05) in order. Acid detergent fiber (ADF) content was increased as the maturity processed, and it showed the highest value at milk stage. However, the contents of ADF in sorghum plant was decreased during the late maturity. Crude protein content of the silage was not significantly different among cultivars used, while NDF content was highest in Ramiki sorgo, followed by Silage sorgo, Kwanganok and Suweon 19. In v i m DM digestibility of the silage was highest in Kwanganok, followed by Suweon 19, Silage sorgo and Ramiki sorgo. Total N content of the silage was highest in Ramiki sorgo, followed by Suweon 19, Silage sorgo and Kwanganok. DM intake of the silage was highest in Ramiki sorgo, followed by Suweon 19, Silage sorgo and Kwanganok and it was closely related to the palatability value.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.288-293
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• 2000

Two rice cultivars (Oryza sativa L.), Hwa-seongbyeo of Japonica type and Taebackbyeo of Indica/Japonica type, were cultivated with hydroponic culture to examine nitrogen effects on the growth responses, contents and utilizations of carbohydrates, and the ripening velocity of grains with three different N levels. Plant height and tiller number were clearly increased to 80 ppm N level compared to 40 ppm N level and then they were slightly decreased in N level of 120 ppm. Higher dry weights were appeared with 80 ppm N level than did with other N levels, showing statistically differences in both cultivars and N levels, while dry weight of roots was heavier with decreasing the N levels. Therefore, T/R ratios were not significantly different among N levels, although there was statistically differences between rice cultivars. After the flowering stage, higher water-soluble carbohydrate (WSC) and water-insoluble carbohydrate (WISC) were contained in stem compared with other parts, showing that WISC of sheath and stem, unlike WSC, was significantly different among N levels. Starch of grain, WISC, was remarkedly increased from 3.0% at just after the flowering to 52.0% and 75.0% at 15 and 30 day after the flowering, respectively, showing that lower N application had faster accumulation of starch in rice grains. N would affect the contents of carbohydrates of each tissue, and starch accumulation in rice grains.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1326-1333
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• 2002

Studies were conducted with nine barrows, average initial body weight $44.5{\pm}2.1kg$, fitted with a T-cannula at the distal ileum, to determine the apparent ileal (and true) digestibility (AID and TID) of CP and AA in different cultivars of rapeseed meals and soybean meal. The barrows were fed either a casein diet or one of eight corn starch-based semipurified diets, formulated to contain 17.0% CP (DM basis) with one of seven different cultivars of rapeseed meal or soybean meal as the sole source of dietary protein, according to a six-period, nine-treatment, incomplete Latin Square. Chromic oxide (0.5%) was used as a digestibility marker. The pigs were fed of 4% of body weight twice daily, at 08:00 and 20:00 h. Ileal digesta were collected at 2 h intervals daily from 5 d to 7 d. The AID or TID values of CP and most AA (Cysteine excluded) were significantly lower in the rapeseed meals than in soybean meal (p<0.05). There were significant differences in the AID or TID values of CP and AA among the seven different cultivars rapeseed meals (p<0.05); the seven rapeseed meals were arranged according to the size of the AA digestibility values of the rapeseed meals from the greatest to the least, as Zayou 59, Youyan 7, Ganyou 16, Qingyou 2, Huaza 3, Ningza 1 and Lianglou 586; differences in CP, AA, NDF and ADF contents in the rapeseed meals were mainly responsible for the variation in the AID or TID values of AA among rapeseed meals. The AID value of CP can be used as an index of the AID or TID values of most AA in rapeseed meals. However, the AID value of CP was less appropriate as a direct indicator of the AID or TID values for cysteine, methionine, tryptophan, phenylalanine and proline.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.2
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• pp.115-120
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• 1990

A series of experiments were carried out for two successive years to investigate the productivity of forage turnip in mid-northern area of Korea. Fresh matter and dry matter yields of 6 foreign cultivars (Purple Top Strap Leaved, Purple Top White Globed, Seven Top, Shogoin, White Egg and Amber Globe) seeded either in early spring or in autumn after harvesting forage corn were evaluated with different seeding date and harvesting date as well as with different level of fertilization. The results obtained are summarized as follows: 1. The earlier the seeding date in spring (Mar. 29, Apr. 12, Apr. 16) was, the higher was the yield of fresh matter and dry matter as the plant growth ceased after mid June, when the temperature began to rise. 2. In spite of its high DM yield, the Japanese cultivar, Shogoin, showed poor forage quality for summer feeding due to its earlier bolting in harvesting season. 3. Of the 6 cultivars Purple Top White Globed showed highest DM yield (800 kg/ 10a) in mid area including SEOUL irrespective of planting season. 4. Although the turnips showed mostly positive yield responses to fertization, the differences were not great especially above the level of$N-P_2O_5-K_2O$: 5-3-4 kg/lOa. 5. IN TAEGWALLYONG, a northern area of Korea, the average fresh matter yield of the six cultivars tested amounted to 3,500 kg/lOa when drilled on June 30 and harvested on Aug. 30, although bulb formation during the summer was relatively poor. 6. Concluded, forage turnip is regarded to be a suitable catch-crop which has the potential to maintain and increase the total forage production in mid-northern area of Korea. The intercropping is recommendable especially for autumn planting well past the time forage corn has been harvested.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.102-108
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• 2019

Pericarp thickness of vegetable corns such as sweet and waxy corn is one of the crucial traits, contributing to their edible quality. This study was carried out to compare the pericarp thickness of super sweet and waxy corn hybrids measured with kernel samples prepared using different methods at different grain filling periods. The samples comprised excised pericarp from dried, frozen (at $-4^{\circ}C$), and fresh kernels. Analysis of variance performed separately on super sweet and waxy corn hybrids indicated a significant three-way interaction among cultivars, kernel sample preparation methods, and days after pollination (DAP). Dried samples of super sweet corn hybrids presented reasonably stable pericarp thickness measurements during grain filling, while all the sample preparation methods fluctuated less as grains of waxy corn hybrids matured. Waxy corn is best consumed at around 24 days after pollination. Pericarp thickness of waxy kernel samples regardless of preparation methods investigated was the same at 24 DAP with a few exceptions. Overall, the common method of drying kernel samples before pericarp excision can provide reliable data for estimating the tenderness of vegetable corn hybrids.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.107-107
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• 2017

Sweet corns are enjoyed worldwide as processed products and fresh ears. Types of sweet corn are based on the gene(s) involved. The oldest sweet corn type has a gene called "sugary (su)". Sugary-based sweet corn was typically named "sweet corn". With its relatively short shelf life and the discovery of a complementary gene, "sugary enhanced (se)", the sweet corn (su only) was rapidly replaced with another type of sweet corns, sugary enhanced sweet corn, which has recessive homozygous su/su, se/se genotype. With the incorporation of se/se genotype into existing su/su genotype, sugary enhanced sweet corn has better shelf life and increased sweetness while maintaining its creamy texture due to high level of water soluble polysaccharide, phytoglycogen. Super sweet corn as the name implies has higher level of sweetness and better shelf life than sugary enhanced sweet corn due to "shrunken2 (sh2)" gene although there's no creamy texture of su-based sweet corns. Distinction between sh2/sh2 and su/su genotypes in seeds is phenotypically possible. The Involvement of se/se genotype under su/su genotype, however, is visually impossible. The genotype sh2/sh2 is also phenotypically epistatic to su/su genotype when both genotypes are present in an individual, meaning the seed shape for double recessive sh2/sh2 su/su genotype is much the same as sh2/sh2 +/+ genotype. Hence, identifying the double and triple recessive homozygous genotypes from su, se and sh2 genes involves a testcross to single recessive genotype, chemical analysis or DNA-based marker development. For these reasons, sweetcorn breeders were hastened to put them together into one cultivar. This, however, appears to be no longer the case. Sweet corn companies began to sell their sweet corn hybrids with different combinations of abovementioned three genes under a few different trademarks or genetic codes, i.g. Sweet $Breed^{TM}$, Sweet $Gene^{TM}$, Synergistic corn, Augmented Supersweet corn. A total of 49 commercial sweet corn F1 hybrids with B73 as a check were genotyped using DNA-based markers. The genotype of field corn inbred B73 was +/+ +/+ +/+ for su, se and sh2 as expected. All twelve sugary enhanced sweet corn hybrids had the genotype of su/su se/se +/+. Of sixteen synergistic hybrids, thirteen cultivars had su/su se/se sh2/+ genotype while the genotype of two hybrids and the remaining one hybrid was su/su se/+ sh2/+, and su/su +/+ sh2/+, respectively. The synergistic hybrids all were recessive homozygous for su gene and heterozygous for sh2 gene. Among the fifteen augmented supersweet hybrids, only one hybrid was triple recessive homozygous (su/su se/se sh2/sh2). All the other hybrids had su/su se/+ sh2/sh2 for one hybrid, su/su +/+ sh2/sh2 for three hybrids, su/+ se/se sh2/sh2 for three hybrids, su/+ se/+ sh2/sh2 for four hybrids, and su/+ +/+ sh2/sh2 for three hybrids, respectively. What was believed to be a classic super sweet corn hybrids also had various genotypic combination. There were only two hybrids that turned out to be single recessive sh2 homozygous (+/+ +/+ sh2/sh2) while all the other five hybrids could be classified as one of augmented supersweet genotypes. Implication of the results for extension service and sweet corn breeding will be discussed.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.26-33
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• 1996

A nutrient solution culture experiment was conducted in the greenhouse at Suwon Campus. Kyung-Hee University from May 23 to July 11. 1995, to determine the effects of potassium application on seedling growth of Kwanganok and Hwengsungok cultivars of corn. Potassium was treated with four different levels, which are 0.248.496 and 744ppm for treatments without potassium (-k), standard potassium concentration (K), double(2k) and triple (3k) of standard potassium concentration, respectively. Plants were harvested at weekly interval for seven weeks. at which time plant height, leaf area and dry matter yield of corn seedling were measured, only chlorophyll content was taken for five weeks from three week after planting. Seedlings growth of Kwanganok and Hwengsungok cultivars was greatly retarded from planting to harvesting time in 3k treatment. The plant height, leaf area and dry matter yield of both cultivars during the whole period were decreased in order of K>2F>-K>3K, but dry matter yield of Kwanganok cultivar was decreased in order of 2K>K>-K>3K. Chlorophyll content of Kwanganok and Hwengsungok cultivars was irregularly fluctuated during growing period. but generally highest in K treatment and lowest in 3k treatment. The crop growth rates of seedlings of both cultivars were slow until the 3rd week after planting. but very fast thereafter. In general, CGR of both cultivars was higher in K and 2k treatments than -k and 3k treatments.