• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.55-58
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• 2000

Germination of sweet and super sweet corn is lower than normal corn due to the higher sugar and lower starch contents of kernels. Sweet corn seeds are easily deteriorated in the field under the unfavorable condition, therefore it is important to identify the optimal harvesting time for seed production. This trial was conducted to investigate the responses of germination percentage of shrunken-2(sh2), brittle(bt), sugary(su), and sugary enhancer(se) hybrids in relation to harvesting dates. Eight hybrids of four different gene sweet corns were harvested at 15, 20, 25, 30, 35, 40, 45, and 50 days after silking(DAS). Germination test was performed using paper towel method. Mean germination percentages across eight hybrids showed the highest value at 45 DAS. There were significant differences among genes and within gene for germination. Shrunken-2 hybrid Mecca was higher than su hybrids for germination, indicating that sh2 would not be poorer than su Late harvesting beyond the optimal harvesting date might not be desirable because of more lodging and ear rots. Theoretical optimal harvesting date estimated from the regression equation was 40.9 DAS, however, practical date for harvesting would be a few days later than the estimated date if seedling vigor might be considered. Kernel dry weight per ear showed similar response to germination. Regression equation showed the highest kernel dry weight at 40.7 DAS. Significant correlations between kernel dry weight and germination were observed, impling that kernel dry matter accumulation would be an important factor for germination.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.125-132
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• 1993

This study was carried out to understand the relationship between sources and sinks in tillering maize hybrid. A non-tillering hybrid was included as check hybrid, The following treatments were imposed on the two hybrids at tasseling stages: 1) no leaves removed, 2) all leaves removed, 3) leaves above 1st ear node removed, 4) leaves below 1st ear node removed and 5) only 1st ear removed. The experiment was arranged in a split plot with hybrids as main plots and treatments as sub plots. Results obtained were summarized as follows: Plant heights in control were significantly higher in both hybrids than other treatments, No significant differences of plant height were observed among treatments of leaf removal in both hybrids. No significant differences of kernel weights of plant were found between locations of leaf removal, But seed weight of tillering hybrids was about 10 to 15% heavier than that of non-tillering hybrid. Stem weight showed the same tendency as the kernel weights. Leaf removal above the ear node lowered kernel weight significantly up to 60% compared with no leaf removal. The leaf removal below the ear node lowered the kernel weight about 40%. The effects of leaf removal on kernel weight was more serious in the non-tillering hybrid than in the tillering hybrid. Contribution of each part to the total dry matter varied with position of leaf removal. When no leaves were removed, contribution of each part to the total dry matter was great in the order of kernel weight, leaf weight and culm weight. When leaves above the ear node were removed, the contribution of each part to the total dry matter was in the order of culm weight, leaf weight and kernel weight. When leaves below the ear node were removed, the contribution of kernel weight was greater than the contribution of leaf and culm weights.

• Plant Resources
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• v.4 no.1
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• pp.31-35
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• 2001

Major characteristics of new Waesungri maize inbred line has multi-tiller and ears: five to six tillers and seven to eight ears per plant and flowering date of Waesungri was delayed about 18 and 24 days compared to Mo17 U.S line and IK$_4$ Korean local lines, respectively. Number of ears, fresh and dry weight per plant were significantly different among all tested hybrids including Waesungri/Sinkihong hybrid under different planting times and densities. Especially, both fresh and dry weight of IK$_1$/FR140//Waesungri F$_1$hybrid were significantly higher at high planting density. In kernel weight per unit area, Wnesungri/Sinkihong hybrid was high at high density and IK$_1$/FR140//Waesungri hybrid was high at low planting density. As results of analysis of variance, flowering date was shown a significantly different both planting times and varieties, while other characters including stem height were shown very variable in interactions with enviromental factors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.70-73
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• 1988

The changes of kernel size, contents of moisture and total sugar, and rates of flavor and stickiness of a waxy corn (cv. Hongcheon native) were observed from 15 days after silking (DAS) to 40 DAS at Suwon and Cheongju in 1984, nespectively. Fresh kernel length and width greatly increased from 15 DAS to 30 DAS and slightly increased thereafter. Fresh 100-kernel weight was markedly increased during 15 DAS to 30 DAS, and slightly and continuously increased thereafter while dry 100-kernel weight almost linearly increased with maturity. Total sugar content of fresh kernel was the highest at 20 DAS and then continuously decreased with maturity. Flavor and stickiness rates of boiled waxy corn were significantly increased during 15 DAS to 30 DAS and flavor rate decreased thereafter. However, stickiness rate maintained the level until 35 DAS and then decreased slightly. The optimum harvest date for fresh waxy corn seems to be about 30 DAS considering kernel size, and flavor and stickiness rates of boiled corn.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.277-286
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• 1985

From a series of studies conducted on the local maize lines at the Agr. College of the Chungnam National Univ., a few maize lines with many tillers and ears per plant were identified and tentatively named as MET. The purpose of the study was to evaluate the MET lines, which were selfed for five generations, for silage purpose under the different plant densities. A hybrid, Suwon #19 and a synthetic variety, Puyo #3${\times}$#2, were included for comparison. Plant height at harvesting times showed no significant varietal differences. However, the MET lines were very slow in early plant growth compared to the hybrid or synthetic variety, probably due to inbreeding depression of the MET lines. Total fresh weight at the harvesting times was highest in the MET 1 line. The MET 1 line was about 2,000 kgr. per 10a. higher than the hybrid at the harvesting time. The highest fresh weight was obtained when grown under the plant density of 60 ${\times}$ 20cm. Total dry weight per unit area showed the same tendency as the fresh weight. Total dry weight of MET 1 line was about 2.4 tons per 10a., which was about 10% higher than the hybrid, Suwon #19. As the fresh weight, the total dry weight was also highest in the plant density of 60 ${\times}$ 20cm. The grain yield per 10 are of MET 1 was comparable to the grain yield of the hybrid, especially in the low plant density, 60 ${\times}$ 40cm. The average number of effective tillers of MET lines were 4.5, while the mean tiller number of the hybrid or synthetic variety were none. However, the lodging was one of the problem for growing MET lines. The 100 kernel weight of MET lines was about 9 gr., while the 100 kernel weight of the hybrid or synthetic variety was about 30 grm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.181-184
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• 2000

This study was carried out to investigate the influence of barley yellow mosaic virus(BaYMV) on agronomic characters in naked barley. A naked barley cultivar, Beagdong was evaluated for disease systems at naturally infected field, National Honam Agricultural Experiment Station. SPAD value of the infected plants by BaYMV was low as compared to healthy plants. Heading time was delayed by 10-11 days. Dry matter weight per plant, culm length, and number of spike per plant were reduced in the infected plants by 75%, 68%, and 49%, respectively. Length of internode was reduced in the first to the sixth internode from the upper part, especially, that in the third to the fifth internode was mostly reduced by 75-80%. Also, length of awn, number of kernels, 1000-kernel weight, and kernel weight per plant of the infected plant were reduced by 17-19%, 47%, 60%, and 78%, respectively. Lightness and redness for kernel color value of Baegdong were low and high, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1399-1406
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• 2011

This study aimed to establish the optimum level of palm kernel meal in the diet of Santa Ines lambs based on the sensorial characteristics and fatty acid profile of the meat. We used 32 lambs with a starting age of 4 to 6 months and mean weight of $22{\pm}2.75kg$, kept in individual stalls. The animals were fed with Tifton-85 hay and a concentrate mixed with 0.0, 6.5, 13.0 or 19.5% of palm kernel meal based on the dry mass of the complete diet. These levels formed the treatments. Confinement lasted 80 days and on the last day the animals were fasted and slaughtered. After slaughter, carcasses were weighed and sectioned longitudinally, along the median line, into two antimeres. Half-carcasses were then sliced between the 12th and 13th ribs to collect the loin (longissimus dorsi), which was used to determine the sensorial characteristics and fatty acid profile of the meat. For sensorial evaluation, samples of meat were given to 54 judges who evaluated the tenderness, juiciness, appearance, aroma and flavor of the meat using a hedonic scale. Fatty acids were determined by gas chromatography. The addition of palm kernel meal to the diet had no effect on the sensorial characteristics of meat juiciness, appearance, aroma or flavor. However, tenderness showed a quadratic relationship with the addition of the meal to the diet. The concentration of fatty acids C12:0, C14:0 and C16:0 increased with the addition of palm kernel meal, as did the sum of medium-chain fatty acids and the atherogenicity index. Up to of 19.5% of the diet of Santa Ines lambs can be made up of palm kernel meal without causing significant changes in sensorial characteristics. However, the fatty acid profile of the meat was altered.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.196-207
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• 2016

In monsoon climates, persistent shade is a troublesome weather condition with an impact on the growth and yield of corn (Zea mays L.). We imposed 7, 14, 21, and 28 days of consecutive shade (CS) on Gwangpyeongok and P3394 corn hybrids at the beginning of the kernel filling stages. Shade had little impact on leaf area and dry matter accumulation in the stem and leaves. However, dry matter accumulation in the ear was severely reduced by approximately 28% and 53% after 14 and 28 days of CS, respectively. For the components of grain yield, 7 and 14 days of shade did irreparable damage to the number of filled kernels, the kernel number per ear row, and the percent of filled kernels, but did little damage or reversible damage after removal of the shade to the 100-grain weight and the row number per ear. Shade significantly reduced the relative growth rate (RGR) due to a decrease in the net assimilation rate (NAR). These results suggest that source activity limitation by shade during the kernel filling stages leads to the inhibition of sink activity and size. The yield of biomass, ear, and grain logistically declined as the length of CS increased. Probit analysis revealed that the number of days of CS needed to cause 25% and 50% reductions in grain yield were 3.7 and 23.1, respectively. These results suggest that the plant yield loss induced by shade at the beginning of the kernel filling stages is mainly achieved within the first 7 days of consecutive shade.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.64-69
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• 2003

Pseudomonas chlororaphis HS21 was isolated from a soil sample and found to produce medium-chain-length polyhydroxyalkanoates (MCL-PHAs) using palm kernel oil (PKO) as the sole carbon source. Up to 3.3 g/1 dry cell weight containing $45\%$ MCL-PHA was produced, when the strain was grown for 21 h in a jar fermentor culture containing 5 g/1 PKO. The polymer produced from PKO consisted of unsaturated monomers of $7.3\%$ 3-hydroxy-5-cis-tetradecenoate and $2.3\%$ 3-hydroxy-5,8,-cis, cis-tetradecadienoate as well as saturated even-carbon number monomers ranging from $C_6\;to\;C_14$, as determined by GC and El GC/MS The PHA was a transparent, sticky material at room temperature. A differential scanning calorimetric analysis revealed that the polymer was amorphous with a $-44^{\circ}C$ glass transition temperature. The number average molecular weight and polydispersity index of the PHA were 83,000 and 1.53, respectively. Although the PHA was practically biodegradable, its degradability was lower than that of poly(3-hydroxyoctanoate) based on a comp:trison of the clear zones formed by growing PHA depolymerase-producing bacteria on an agar plate containing the respective polymers.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.1
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• pp.99-105
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• 2004

The present agricultural water quality standards are set by a policy goal. This is intended for water quality management of public water resources, but not for the use of water resources. These standards were not determined by considering the influence of water quality on the safety of agricultural produce and the growth, yield and quality of agricultural crops. Thus, this study was carried out to investigate the influence of irrigation water quality on the growth, yield, and grain quality of rice and acquire fundamental knowledges to set up irrigation water quality standards. The pot experiment was conducted with 4 treatments using irrigation waters with various total nitrogen concentrations (control, 1, 5, 10, 20mg/L) and replicated four times with randomized block design. The results of this study showed that plant height, number of tiller, plant dry weight, the uptake of N, P, and K, and rice protein contents tended to increase as the T-N concentration in irrigation water was increased. In addition, grain yield at T-N 20 mg/L was significantly higher than in the control, but the percentage of head rice was slightly lower due to the increase of green kernel and white belly/core kernel.