• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.104-104
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• 2003

In this study, seven grain seeds(sorghum maize, buckwheat, soy bean, mung bean, red bean, and barngrass) and germinated seven grain seeds were examined the fibrinolytic activity through fibrin plate assay and SDS-PAGE. The results obtained were as follows : 1. In the fibrin plate assay, the extracts of maize, barngrass, sorghum and buckwheat showed fibrinolytic activity. Especially, Maize of them showed fibrinolytic activity that was almost similar to plasmin, fibrinolytic enzyme used as a positive control. 2. In the SDS-PAGE of seven grain seeds, fibrinolytic activity was remarkably shown in mung bean and red bean. 3. In the fibrin plate assay of germinated grain seeds, buckwheat(5 mm), buckwheat(10 mm) and soy bean(10 mm) showed a level of fibrinolytic activity that was about 0.3 fold than 1.0 unit of plasmin, Also maize(10 mm) of them showed a level of fibrinolytic activity that was about 0.5 fold than 1.0 unit of plasmin. As a result, maize of grain seeds was found that it has a strong fibrinolytic activity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.232-238
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• 2010

Maize double cropping with winter cereals is important for round-year production of forage or grain, and increase of self-sufficiency of upland grain crops such as maize and wheat. Changes of maize growth and yield for forage or grain according to late planting in June for double cropping with winter barely were investigated compared to proper planting in April for three years from 2007 to 2009. Forage and grain yields of maize planted in mid or late June decreased by 20~30% compared to proper planting in April, but total grain yields per year of double cropping increased by 30~40% compared to single cropped maize. Reduction of ear dry matter was less than that of stalk in late planting within maize plant part. Yield reduction by late planting was the least at Kwangpyeongok, which showed the highest grain yield, 850 kg $10a^{-1}$ in even though late planting in June. Meteorological condition during harvesting time of double cropped maize, which in late September (forage) and mid October (grain), were better than that of conventional maize harvesting time which in late August and mid September. It is thought that more researches for double cropped maize for higher grain production is needed in the future.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.345-345
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• 2017

In order to reduce rice cultivation area in paddy fields and to increase domestic self-sufficiency of imported upland grain, it is necessary to increase double cropping area of upland crops in paddy field in accordance with decrease of rice consumption in Korea. The double cropping of spring potato-summer grain maize can be combined because of enough growing season in the southern plain of Korea. Spring potato, which is profitable, can be planted in the late February and harvested in the late May as the main crop. Subsequent grain maize can be planted in early June and harvested in November (maturity in the early October). Spring potato (variety Soomi) yielded $2,544kg\;10a^{-1}$ (tuber) when planted in late February, 2016. When maize was planted in June as the second cropping crop, though growth of plant decreased much, grain yield decreased slightly compared to normal planting in April or May. There was enough time to dry maize ear in the field after maturity before harvesting, which saved labor and time for grain drying, since there is no autumn planting at the double cropping of spring potato-summer grain maize. When grain maize (variety Gwangpyeongok) was planted in the early June (June $10^{th}$), average grain yield of above $860kg\;10a^{-1}$ over 2 years of 2015 and 2016 was obtained, and the annual total yield (potato tuber + maize grain) of 3,400 kg $10a^{-1}$ was obtained. The result indicates that the double cropping of spring potato-summer maize using paddy fields in southern plain of Korea, could contribute to the self-sufficiency of upland crops through the maximum production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.1-5
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• 2001

Field experiment was conducted during 1993-94 season to determine the pattern of nutrient uptake and productivity of maize/sweet potato intercropping system. Four levels of nitrogen (0, 50, 100 and 150kg N ${ha}_{-1}$) and four levels of potassium (0, 40, 80 and 120kg $K_2$O ${ha}_{-1}$) formed treatment variables. Plants were sampled periodically to determine dry matter and tissue concentrations of N and K in the individual plant components of intercropped maize and sweet potato. Nitrogen and potassium fertilizer did not interact significantly to nutrient uptake by any plant parts of intercropped maize and sweet potato. But application of N fertilizer independently enhanced N uptake in all the plant parts of maize and sweet potato. The uptake of N in leaf, leaf sheath, stem, husk, and cob of maize increased upto 90 days after planting (DAP) but grain continued to accumulate N till its maturity. Sweet potato exhibited a wide variation in N uptake pattern. Sweet potato leaf shared the maximum uptake of N at 50 DAP which rapidly increased at 70 DAP and then declined. Declination of N uptake by petiole and stem were observed after 120 DAP whereas N uptake by tuber increased slowly upto 90 DAP and then rapidly till harvest. Rate of applied K had very little effect on the uptake patterns in different components of intercropped maize. Pattern of K uptake by leaf, petiole and stem of sweet potato showed almost similar trend to N uptake. But uptake of K by tuber increased almost linearly with the K application. Pattern of N and K uptake by grain and tuber paralleled the grain yield of maize and sweet potato respectively. Intercropped productivity of maize and sweet potato found to be better by the application of 100kg N and 120 kg $K_2$O ${ha}_{-1}$

• Research in Plant Disease
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• v.29 no.2
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• pp.137-144
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• 2023

Exserohilum turcicum is a fungus that causes northern corn leaf blight (NCLB) and has deleterious effects on maize production globally. Therefore, it is prudent to mitigate the effects of NCLB using genetic diversity. The objective of this research was to assess the severity of NCLB disease on the growth and yield of various maize genotypes. A randomized complete block design field experiment, replicated three times, was conducted to evaluate the effect of E. turcicum on 10 maize hybrids. Percent disease index, plant height, and leaf area were recorded at the silk stage. Cob weight, grain fresh weight, and grain yields were determined at harvest maturity. All measured parameters were significantly different (P<0.05) between the maize hybrids. Of the 10 genotypes, four (PAN 4R-528R, PAN 4R-728BR, PAN 3R-724BR, and P1788BR) were susceptible, five (DKC74-74BR, PAN 5R-582R, PAN 5R-890R, PAN 5R-854R, and PAN 5R-590R) were moderately susceptible, and one (DKC80-40BR) was moderately resistant. DKC80-40BR exhibited greater cob weight, while DKC74-74BR was superior in all other plant growth and yield components. Interestingly, although not significant (P>0.05) and high, maize growth and yield parameters had negative correlations with disease incidence, except for grain fresh weight. Therefore, DKC80-40BR may be selected for cultivation in areas prone to NCLB to reduce maize susceptibility to the disease, while DKC74-74BR may improve crop performance. These hybrids could be considered as potential sources of resistance or tolerance to NCLB for further validation by plant breeders.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.158-173
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• 1993

The formulated mechanization packages for grain maize production have performed to the expected limit generating encouraging information. Besides physical feasibility , management factors viz ; production operation sequence, operations scheduling and machinery matching with respect to environment can still limit system suitability. A new production operation sequence was introduced to overcome weed problems and limitations of available working days. Proper operations scheduling will improve the initial soil-crop environment for better seedling establishment, and reduce the (). been identified as key factors to reduce capital investment and cost of proudction .

• Korean Journal of Agricultural Science
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• v.44 no.2
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• pp.196-210
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• 2017

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia cepacia (C1) and Alcaligenes aquatilis (H6), was assessed in liquid medium and maize plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus (309.66 ?g/mL) into the medium, followed by single inoculation of B. cepacia (305.49 ?g/mL) and A. aquatilis strain (282.38 ?g/mL). Based on a plant growth promotion bioassay, co-inoculated maize seedlings showed significant increases in shoot height (75%), shoot fresh weight (93.10%), shoot dry weight (84.99%), root maximum length (55.95%), root fresh weight (66.66%), root dry weight (275%), and maximum leaf length (81.53%), compared to the uninoculated control. In a field experiment, co-inoculated maize seedlings showed significant increases in cob length (136.92%), number of grain/cob (46.68%), and grain weight (67.46%) over control. In addition, single inoculation of maize seedlings also showed improved result over control. However, there was no significant difference between single inoculation of either bacterial strains and co-inoculation of these two bacterial strains in terms of phosphate solubilization index, phosphorous release, pH of the media, and plant growth parameters. Thus, single inoculation and co-inoculation of these bacteria could be used as biofertilizer for improving maize growth and yield.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.346-346
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• 2017

In Northern Laos, maize is cultivated in continuous cropping without fertilizer, fallowing nor any other soil conservation practice. It is expected that this inadequate management in maize cultivation will degrade soil and decrease yield. However, there is limited information about the change of soil condition and yield under continuous maize cultivation. We tried to evaluate the change of soil condition and yield under continuous maize cultivation in Northern Laos. Our study was conducted in farmer's flat and slope fields in Sainyabuli province where maize cultivation had been introduced earlier than the other provinces of Northern Laos. Our study was conducted in 21 fields in 2014, and in 19 fields in 2015. We analyzed grain yield and soil characteristic (total carbon (TC), total nitrogen (TN), available phosphorus (Av-P), exchangeable cation, pH, soil texture) at 3 places in each field. The 3 places were set at different elevation level (lower position, middle position, upper position) in slope fields. Further, the period of continuous maize cultivation and crop management practice were investigated. Then, by evaluating the relation between the period of continuous maize cultivation and yield and the soil characteristics, the effect of maize cultivation was estimated. Crop management practices were similar among the investigated fields. Maize was cultivated in rain season. Grain seed and cob were harvested on September or October, but shoot was left on the fields. No crop was cultivated during dry season. Fertilization and fallowing has never been conducted under continuous maize cultivation. On the other hand, the period of maize cultivation was different among the fields, and ranged from 2 years to 30 years. In the slope fields, as the period of continuous maize cultivation was longer, the contents of TC and TN were lower at all 3 positions, Av-P content was lower at the upper position, exchangeable potassium (Ex-K) content was lower at the middle and the upper positions. The other soil characteristics weren't related with the period of maize cultivation in the slope fields. In contrast, soil characteristics weren't related with the period of maize cultivation in the flat fields. Yield was lower as the period of maize cultivation was longer at the upper position of the slope fields. At middle position of slope fields, yield tended to be low with increase of the period of maize cultivation. In contrast, yield wasn't related with the period of continuous maize cultivation in flat fields. From the results about crop management, it was presumed that the period of maize cultivation was one of the main factors causing the difference of yield and soil characteristics among the fields. Therefore, from the result of yield and soil condition, it was considered that the continuous maize cultivation decreased soil productivity in the slope fields with decline of TC, TN, Av-P, Ex-K and yield at upper position of slope fields, and decline of TC and TN in the other positions in Sainyabuli province.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1239-1244
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• 2000

In order to investigate the effect of incorporation of thermally processed cereal (maize) grain and differently degradable protein sources in the calf starter, twenty four newly born crossbred $(Bos\;taurus{\times}Bos\;indicus)$ calves were assigned at random to six diets in a $3{\times}2$ factorial design involving three protein sources viz. groundnut meal (GN), cottonseed meal (CS) and meat and bone meal (MB), each along with two differently processed grain, namely ground raw (R) and pressure cooked (P) maize. The corresponding calf starters with green oats (Avena sativa) were given free-choice from 14 d onwards till the end of the 90 d experimental feeding. A restricted milk diet was fed till the age of weaning at 60 d. Total DM intake was not affected by cereal or protein sources. However, daily intake of DM (59.23 vs 66.45 g) and CP (12.38 vs 14.10 g) per kg $W^{0.75}$ was reduced (p<0.05) due to cereal processing. Better (p<0.05) feed and protein efficiencies after weaning and during entire period in calves fed processed maize resulted in a trend of higher $(p{\leq}092)$ growth rate especially when GN was the source of protein. In comparison among protein sources, calves fed MB diets tended to grow faster $(p{\leq}098)$ concurrent with a higher CP intake before weaning. It is thus evident that thermal processing of maize in the calf starter seems to improve calf performance. Moreover, results indicated that feeding of protein and starch sources of matching ruminal degradability may prove beneficial for early growth of crossbred calves.

• 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.