• Journal of The Korean Society of Grassland and Forage Science
• /
• v.19 no.1
• /
• pp.31-40
• /
• 1999

This study was conducted to investigate the effects of rhizosphere bacterium and pathogenic fungi on the growth of corn(Zea may L.) in continuous corn cultivation soil(CCCS) and non-continuous cultivation soil(NCCS). Corn was established by seeding into pots of 30 cm in diameter and 50 cm in depth containing 1 : 1 mixture of soil and vermiculite. Rhizobacterium and pathogenic fungi were inoculated into the soils. The field experiment was carried out at the Animal Research Station, College of Agriculture, Chonnam National University. Sample of corn was taken from each pot at 50 days and 90 days after sowing. Corn was cultivated in a vinyl house with three replications under natural daylight conditions. The bacterium used in this study was Bacillus subtilis. B. subtilis was directly isolated and identified from forage rhizosphere soil. Dry matter(DM) of coron plant in treatment without B. subtilis was lower than that in treatment of B. subtilis. DM of corn plant inoculated with B. subtilis was higher than that of corn inoculated with pathogenic fungi in both CCCS and NCCS. DM of corn plant in NCCS was more increased than that in CCCS. The effect of B. subtilis inoculation on the growth of corn was better in NCCS than in CCCS. However, DM of corn plant was apparently decreased by the inoculation of the pathogenic fungi in both CCCS and NCCS.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.17 no.4
• /
• pp.315-322
• /
• 1997

Sixteen cultivars of corn(Zea mays L.) hybrids have been recommended as the government recommended corn hybrids since 1984, however, their forage performances have been mostly tested at two locations, such as Suweon and Sunghwan in the Middle parts of Korea. Therefore, the objective of this experiment was to retest the agronomic characteristics and yield of eleven of sixteen government recommended corn hybrids at five scattered locations, such as Icheon, Suweon, Sunghwan, Keonpan and Kwangju in 1993 and 1995 with the intention of improving recommendations to dairy farmers. Among the corn hybrids tested, 'Suweon 19' was susceptible to foliar diseases and poor stay green at all locations in 1993 and 1995. Generally, all hybrids have less lodging and infection rate of rice black streaked dwarf virus(RBSDV) varied by location but mostly not exceed 10%. Infection rate at Sunghwan and Kwangju among locations was the highest as 13.5 and 15.3% respectively. Among the corn hybrids tested, 'Suweon 19' was the highest RBSDV infection rate, but that of 'Kwanganok' and '3282' was lower than other hybrids. At all locations, '3352' and '3394' were the earliest in growth stage, but 'Kwanganok', '3282', 'DK729', 'G4624' and 'DK713' were the latest among the corn hybrids. Ear percentage in total DM of '3352', '3394' and 'G4624' was higher than other hybrids, but that of 'DK713' was the lowest among the corn hybrids. '3352' and '3394' showed the most suitable DM content for silage production at harvest. Among the corn hybrids tested, 'Suweon 19' and '3282' were the lowest DM yield at all locations in 1993 and 1995, but the highest DM yield varied by location. At Icheon, '3144W' and 'G4743', at Suweon, '3352' and '3144W, at Sunghwan, 'DK729' and '3144W', at Keongsan, '3352' and 'DK729', and at Kwangju, '3352' and 'DK689' were the highest DM yield in 1993 and 1995, respectively. Then, '3394' was higher than other hybrids at all locations in 1995. The government recommended corn hybrids tested were generally adapted across the country. However, in forage production situations where wrn should be harvested before the rainy season in late summer, earlymedium maturing corn hybrids, '3352' and '3394' might be preferred.

• Journal of the Korean Wood Science and Technology
• /
• v.32 no.5
• /
• pp.29-38
• /
• 2004

In this study, we investigated the thermal properties of corn-starch filled polybutylene succinate-adipate (PBS-AD) bio-composites. Thermal analysis (TA) is used to describe the analytical method for measuring the chemical property and weight loss of composite materials as a function of temperature. The thermal stability of corn-starch was lower than that of pure PBS-AD. As corn-starch loading increased, the thermal stability and degradation temperature of the bio-composites decreased and the ash content increased. It can be seen that the degree of compatibility and interfacial adhesion of the bio-composites decreased because of the increasing mixing ratio of the corn-starch. As the content of corn-starch increased, there was no significant change in the glass transition temperature (T_g) and the melting temperature (T_m) for the bio-composites. The storage modulus (E') and loss modulus (E") of the corn-starch flour filled PBS-AD bio-composites were higher than those of PBS-AD, because of the incorporation of corn-starch increased the stiffness of the bio-composites. At higher temperatures, the decreased storage modulus (E') of bio-composites was due to the increased polymer chain mobility of the matrix polymer. From these results, we can expect that corn-starch has potential as a reinforcing filler for bio-composites. Furthermore, we recommend using a coupling agent to improve the interfacial adhesion between corn-starch and biodegradable polymer.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.19 no.3
• /
• pp.211-220
• /
• 1999

The corn is mostly planted in mid-April in single-cropping silage system if possible, however, in a double-cropping silage system, the corn planting date is delayed until after the mid-May. The objective of this study was to evaluate agronomic characteristics and forage performance of the eight government recommended corn hybrids for silage at two dates of planting. Split-plot design replicated three times was used, that is, main plots were planting dates, sub-plots were eight hybrids at Suweon in 1997. Days from planting to silking of optimum planting was 84 days and that of late was 69 days. The difference in silking day among the hybrids was 6 days at optimum planting and 2 days at late planting. Plant height of optimum planting corn was higher than that of late one, however, ear height and stem diameter of optimum planting were lower than those of late planting corn. Among the corn hybrids tested, plant heights of 'P3156' and 'P3163' were higher than those of the other hybrids. Ear height of 'DK713' was the lowest among the corn hybrids and stem diameter of 'P3394' was thicker than that of the other hybrids. European corn borer(ECB) damage(16.6%) at optimum planting was lower than that(49.9%) of late, however, there were no significant ECB damage differences among the corn hybrids tested. Whole plant dry matter(DM) contents of 'P3525', 'P3394' and 'P3352' hybrids were higher than those of the other corn hybrids at harvest. Ear percentages of the total dry matter(DM) of 'P3394' and 'P3156' were higher than those of the other corn hybrids. Dry matter(DM) and total digestible nutrients(TDN) yields(19,696 and 14,621kg/ha) at optimum planting were higher than those (17,163 and 12,570kg/ha) of late planting, while there were no significant differences in DM and TDN yields among the corn hybrids tested. And those hybrids with greater proportion of grain in the whole plant have higher DM and TDN yields. Correlation coefficients for days from planting to silking with DM and TDN yields were $0.84^{**}$ and $0.87^{**}$, and those for ear percent were $0.86^{**}$ and $0.87^{**}$. Results of this study indicate that optimum planting date(15 April) is better than late planting date(16 May) in agronomic characteristics and forage production of silage corn. Days from planting to silking and ear percent as welI as other characters are important factors screening the corn hybrid for silage.

• Korean Journal of Agricultural Science
• /
• v.45 no.3
• /
• pp.419-427
• /
• 2018

The present study was conducted to investigate the effect of different levels of Korean corn grain on in vitro ruminal fermentation with total mixed ration (TMR) as a basal feed. Three ruminal cannulated Holstein steers (Body Weight $479{\pm}33.0kg$) were used as rumen fluid donors. Treatments for in vitro fermentation were TMR only (control, 3.0 g), TMR substituted partially with high level (HC, TMR 1.5 and corn 1.5 g), and with low level of Korean corn grain (LC, TMR 2.25 and corn 0.75 g), respectively. To measure in vitro ruminal pH, gas production, ammonia N and volatile fatty acids (VFA), the in vitro fermentation incubation was triplicated at $39^{\circ}C$, 120 rpm for 0, 1, 3, 6, 12, 24 and 48 h, respectively. Mean ruminal pH was significantly lower (p < 0.05) for HC than control. Changes in rumen pH was rather similar between the groups till 6 h after incubation, but the lowest pH for HC (pH 5.10) appeared at 48 h compared with control and LC. Total gas production was tended (p < 0.09) to be higher and ammonia N was significantly lower (p < 0.05) for HC than control and LC. Total VFA was higher (p < 0.05) for HC and LC than control but no differences appeared between HC and LC. Overall, the present data indicate that feeding different levels of Korean domestic corn grain may lead to high and sustainable starch degradation in the rumen.

• The Korean Journal of Ecology
• /
• v.13 no.1
• /
• pp.1-8
• /
• 1990

Effects of mycorrhizal infection on the growth of bell pepper (Capsicum annuum) and corn (Zea mays) seedlings have been studied by comparing plants grown in sterilized soil/sand mixtures to plants grown in sterilized soil/sand mixtures with topping the original non-sterile field soil. The original nonsterile field soil, which were taken from the bell pepper field, contained a high level of endmycorrhizal spores. After seven weeks, the shoot height of inoculated plants was increased by 110% in bell pepper, and 90% in corn compared with the control plants. The average above-ground biomass of inoculated plant was increased by 88% in bell pepper and 71% in corn compared with the control plants. The shoot-root ratios in bell pepper and corn were 2.7 and 1.8 for the control plants, and 4.3 and 2.7 for the treatment plants, respectively. Phosphorus level in inoculated plant was higher than that of the control plant. However, nitrogen contents were similar between the control and the treatment plants. The control plants didi not form vesicular-arbuscular mycorrhizae during the experimental period.

• Food Science and Biotechnology
• /
• v.17 no.5
• /
• pp.1021-1024
• /
• 2008

Genistein, one of the isoflavones in doenjang, is generally known to prevent various cancers, osteoporosis, climacterium, and menopause symptoms, and has better bioavailability and healthful physiological effects than its glucoside, genistin. In both traditional and commercial doenjangs, genistein content ranged from 370 to 1,510 mg/kg, however, significant amounts of genistin also existed at the level of 190 to 350 mg/kg. After treating with corn $\beta$-glucosidase, over 84% of genistin in doenjang was converted to genistein. However, physiochemical characteristics such as pH, viscosity, 2-thiobarbituric acid (TBA) value, and color were not changed significantly after corn $\beta$-glucosidase treatments. Therefore, this study shows that the improved doenjang with the increased genistein content can be produced using corn $\beta$-glucosidase.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.9
• /
• pp.1348-1350
• /
• 2010

Conidia of Beauveria bassiana ARSEF-7060, produced in millet amended with plant oils such as sunflower, corn, or cotton seed oil, were exposed to $45^{\circ}C$ of wet heat for 90 min. Conidia from millet+corn oil medium had the highest thermotolerance [$LT_{50}$ (median survival time): 45.7 min]. The mycotized millet grains were coated with each of the same plant oils as a granular formulation and subjected to $50^{\circ}C$ of dry heat for 8 h. Corn oil coating ($LT_{50}$: 8.68 h) was superior to sunflower and cotton seed oil coatings, suggesting the feasibility of using corn oil to increase conidial thermotolerance.

• Toxicological Research
• /
• v.13 no.4
• /
• pp.367-370
• /
• 1997

Fumonisin $B_{1}$ ($FB_{1}$) is hepatotoxic in all species, and initiator and promotor for hepatocarcinogenesis produced mainly by Fusarium moniliforme. This fungus is commonly natural contaminant of corn and other grains worldwide, and has been associated with animal and human diseases. In these study, natural occurrence of $FB_{1}$ was surveyed in 30 healthy domestic corn kernels in Chonbuk and Kangwon province, harvested in 1994 and intended for human consumption, and 15 imported American and Chinese samples of each, collected from different ship-loading at Inchon harbor for animal foodstuffs. $FB_{1}$ contents were measured by high-performance liquid chromatography (HPLC) with a fiourescence detector. The data revealed that 2 out of 12 corn kernels from Kangwon province with 1.1 and 0.7 ppm, and 2 out of 18 corns from Chonbuk province with 0.5 and 1.3 ppm, respectively. However, there was no detection of $FB_{1}$ in imported corn samples, even though those were visibly moldy.

• Journal of Sericultural and Entomological Science
• /
• v.19 no.1
• /
• pp.15-18
• /
• 1977

This study carried out to know whether corn shank can be used as the crude fiber source for the larval growth or not, The results obtained from this study are summarized as follows: 1. It seems that there are no bad effects of the artificial diet containing corn shank on feeding of the newly hatched larva. 2. Author did not find any bad effects of the artificial diet containing corn shank on larval growth and cocoon qualifies. 3. In view of these results, it seems that the corn shank is suitable for use as the crude fiber source for the silkworm artificial diet.