• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.585-593
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• 1994

This study was conducted to know optimum ground water level for maize(Suwon 19) and sorghum-sudangrass hybrid(Pioneer855F) and investigated effect of different soil types and ground water levels on growth of above two crops at containers were controlled so as to be 25, 35, 50, 70 and 100cm from the soil surface. Both crops showed better growth in sandy loam soil. Optimum ground water level for maize was l00cm and for sorghum-sudangrass hybrid was 70cm in sandy loam soil. Clay loam was unfavorable for both crops even though low ground water level maintained. Sorghum-sudangrass hybrid was adapted better to clay loam soil and high ground water levels. In microscopic study on root anatomy of both crops, destructed cortical tissues were observed. Frequency of the tissues was higher in maize than in sorghum-sudangrass hybrid and higher at mid or tip parts than basal parts of roots in both crops. Arrangement of cortical cells of roots in sorghum-sudangrass hybrid were more regular than those of maize. In root anatomy, no consistent trend with soil types or ground water levels was detcted.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.51-58
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• 2012

Salinity is one of the most relevant abiotic factor limiting crop yield and its net primary productivity. In addition, salinity induces an increased stress ethylene synthesis in plants which, in turn, exacerbate the responses to the stressor. Bacterial single or co-inoculation effect was tested using previously characterized plant growth promoting (PGP) bacteria Brevibacterium iodinum RS16 and Methylobacterium oryzae CBMB20 on maize and sorghum-sudan grass hybrid under different concentrations of NaCl. Non-inoculated maize and sorghum-sudangrass hybrid showed 33.4% and 20.0% reduction in seed germination under highest NaCl (150 mM) level tested. However, under the same NaCl concentration, co-inoculation with B. iodinum RS16 and M. oryzae CBMB20 PGP strains increased the seed germination in maize (16.7%) and sorghum-sudangrass hybrid (4.4%). In Gnotobiotic growth pouch experiments conducted for maize and sorghum-sudangrass hybrid, co-inoculation of PGP B. iodinum RS16 and M. oryzae CBMB20 mitigated the salinity stress and promoted root length by 22.9% and 29.7%, respectively. Thus the results of this study could help in development of potential bioinoculants that may be suitable for crop production under saline conditions.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.6-8
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• 2011

In order to produce the organic foods in accord with international standard, organic seeds should be used in organic farming. This study was conducted to establish the stable production of organic seed of waxy com by examining the growing characteristics, seed yield, and the economy for seed production by organic farming. The optimal sowing timing for organic seed production of waxy com hybrid was within 10 days of the $1^{st}$ of May with yield of 88~90% of conventional seed production. The optimal planting density was 41,600 plants/ha ($80{\times}30$ cm) for organic seed production of waxy com. The weight of 100 seeds and seed productivity increased at the planting ratio of 2:1 mother plant:male plant. Growth and seed production were improved by removing male plant at 7~10 days after silking. Organic fertilizer (mixed oil cake) was applied at a rate of 4~6 Mg/ha before sowing. Black plastic mulching was used for weed control. In addition, sex pheromone trap and bio-control agents were used for safe pest control and low labour cost.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.1-7
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• 2014

The objective of this study was to determine the effect of single and co-inoculation of plant growth promoting bacteria (PGPB) on early plant growth in Saemangeum reclaimed soil. Plant growth promoting Brevibacterium iodinum RS16 and Methylobacterium oryzae CBMB20 were inoculated on maize (Zea mays L.) and sorghum-sudangrass hybrid (Sorghum bicolor L.) grown in Saemangeum reclaimed soil. Single and co-inoculation of B. iodinum RS16 and M. oryzae CBMB20 increased plant height, dry biomass accumulation and macro-nutrient accumulation of maize and sorghum-sudangrass hybrid. M. oryzae CBMB20 treatment increased plant height in maize by 41.2% at 30 days after sowing (DAS), shoot dry weight and total dry weight compared to non-inoculated treatment. Macro-nutrient accumulation (N and P) in maize roots was significantly increased with co-inoculation treatment, K and Ca content was significantly increased at B. iodinum RS16 treatment compared to non-inoculated treatment. Macro-nutrient accumulation (P, K, Ca and Mg) in shoot was higher with M. oryzae CBMB20 treatment compared to non-inoculated treatment. In case of sorghum-sudangrass hybrid, co-inoculation treatment showed 33.7% increase in plant height compared to non-inoculated treatment at 30 DAS. M. oryzae CBMB20 treatment increased root dry weight and total dry weight, macro-nutrient accumulation in roots and N, Ca and Mg accumulation in shoot compared to non-inoculated treatment. P and K accumulation in shoot was significantly increased at co-inoculation treatment compared to non-inoculated treatment. This pot culture experiment demonstrated that single and co-inoculation of B. iodinum RS16 and M. oryzae CBMB20 increased the early growth and nutrient accumulation of maize and sorghum-sudangrass hybrid.

• Korean Journal of Agricultural Science
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• v.19 no.2
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• pp.269-272
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• 1992

A new single glutinous maize hybrid "Huin Chal 1" was developed at the Genetics and Breeding Lab., Dept. of Agron., College of Agriculture, Chungnam National University. Parents for the hybrid were all derived from Korean indigenous maize lines which were collected in 1980s. One of the parental inbred lines was originated from Bosung, Chonnam province and other inbred line was from Jewon, Chungbuk province. Both inbreds were developed by ear-to-row selection method through selling and named as Bosung and Jewon, respectively. Performace tests for the hybrid which was produced between Bosung and Jewon have been conducted five times including one test at Crop Experiment Station, Rural Development Administration. From the previous performance tests, the hybrid was recognized as high yielding hybrid with good agronomic characteristics and we named the hybrid as Huin Chal 1., and hereby we report the agronomic characters of the newly developed hybrid.

• Korean Journal of Agricultural Science
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• v.33 no.1
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• pp.67-72
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• 2006

This study was carried out to compare a yield performance about CNU maize hybrids developed at the Maize Genetics and Breeding Lab. in Chungnam National University. Among the hybrids incorporated in the test, CNU 3 and 1 showed higher dry matter per 10a and lower kernel yield per 10a than check hybrid, Kwanganok. Hongchon 5 and Suwon169 showed higher kernel yield than Kwanganok. The average yield of CNU 3 hybrid in dry matter and CNU 4 in kernel yield were 2,106kg/10a and 854kg/10a in regional adaptability test, which were increased 33% and 8% compared with a check hybrid, respectively. Also, these hybrids had better stay green characteristics than check hybrid and showed moderately resistance to corn borer and leaf spot.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1619-1624
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• 2003

The effect of maize hybrid (Suco and Dekalb 765, DK 765), maturity stage (milk, $R_3$ and 1/2 milk line, $R_5$) and animal diet (Diet 1: 70% lucerne hay+30% maize silage; Diet 2: 50% maize silage+20% sunflower meal+30% maize grain) on ruminal stover dry matter (DM) degradability was studied. Additionally, morphological and chemical plant composition was evaluated. Fodder samples ground at 2 mm were incubated in three Holstein steers (400 kg body weight) using the in situ technique. Ruminal degradation kinetics was studied and the effective degradability (ED) was estimated for an assumed kp of 5%/h. The in situ data was analyzed in a complete randomized block design with the animals as blocks. Significant interactions between hybrid${\times}$diet and maturity${\times}$diet on kinetic digestion parameters were detected. In Diet 1, hybrids did not differ in degradable fraction, kd or ED, although a minor difference (p<0.05) in the soluble fraction was found (25.5 and 23.2% for Suco and DK 765, respectively). In Diet 2, the DK 765 had greater degradable fraction (p<0.001) but smaller (p<0.01) kd than Suco, without differences in the soluble fraction or in ED. Anticipating the harvest increased ED of stover from 37.5% in $R_5$ to 44.6% in $R_3$ (average values across hybrids and diets) due to the increase (p<0.001) in the soluble fraction ($R_5$: 22.6%, $R_3$: 28.8%). It is concluded that hybrids had similar stover in situ DM degradability and that soluble fraction represent the main proportion of degradable substrates. Advancing the date of harvesting may not improve the in situ DM degradability of whole maize plant silage since the increase in stover quality is counteracted by the depression in the grain-to-stover ratio. The diet of the animal consuming silage might not improve stover utilization either.

• Korean Journal of Plant Resources
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• v.17 no.3
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• pp.304-313
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• 2004

This study was conducted to find out the scientific maize breeding protocol for developing high performing single cross hybrid using introduced U.S. elite inbred lines; the pattern of inheritance, heterosis and heritabilities of six agronomic traits were studied in the progenies derived from five crosses (Mo17/B14A, Va85/B73, C103/ND203, FR35/Oh43, Wf9/A632). Among the five cross combinations, the cross combination of Mo17/B14A showed the highest heterosis for the most agronomic traits. Among 6 agronomic traits, the grain yield showed the highest heterosis effect in most cross combinations. Most of the agronomic traits in this study showed more than 50% heritability for six cross combinations, with an exception of the ear length trait. In conclusion, since Mo17/B14A showed excellent performance for most of the agronomic traits, these inbred lines were desirable combination and regarded as superior germ plasm sources for F1 hybrid development. The results of current studies will be utilized for developing high performing single cross hybrid from maize inbred lines, and will be used for the further genetic analysis of agronomic traits and maize breeding programs.

• 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 Agricultural Science
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• v.34 no.2
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• pp.131-134
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• 2007

This study was carried out to identity the major characteristics of inbred lines and to develop early waxy colored hybrid at the Maize Genetics and Breeding Lab. in Chungnam National University. The eight colored waxy maize were planted on April 27, 2007 under Randomized Completely Block (RCB) Design with three replications. Stem height of IK1/H26-2 and Heunchal lines in this experiment were high as 196cm and 186cm compared to control as 156cm, respectively, while ear height of Local-2 and IK/LE were lower than that of check and ear diameter of IK/H26-1, IK/H26-2 and Local-2 were 10.3mm, 17.7mm and 18mm compared to control (21mm), respectively. Days to tasseling of Local-1, Local-2, and IK/LE lines were earlier than check. As a result of this experiment, the developed inbred lines were regard as useful germplasm for early hybrid development.