• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.84-90
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• 1986

An experiment was conducted to know the effects of planting dates (March 5, 15, and 25 and April 4) and transparent polyethylene (P.E.) film treatments(tunnel, tunnel slit, and mulch) on air and soil temperatures and growth and yield of a sweet corn variety, Great Bell. Maximum air and soil temperatures and minimum air and soil temperatures were greater at tunnel>tunnel slit>mulch in that order. Differences in maximum air and soil temperatures among the P.E. film treatments were much greater than those in minimum air and soil temperatures. However, when film was opened due to high air temperature over 40$^{\circ}C$ in the tunnel, air temperature was similar but soil temperature was lower com-pared to mulch. High temperature stress could be avoided in tunnel slit without opening film by increase in the number of slits. Cold damage of corn seedlings was avoided by tunnel and reduced by tunnel slit, and frost-damaged seedlings under the mulch were recovered in few days. The number of days from planting to silking was reduced as planting date delayed. At early plantings, tunnel enhanced early growth and silking, but it delayed at late plantings because tunnel was opened during the most of day time due to high temperature. Black streaked dwarf virus(BSDV) disease was more severe at early plantings and it was reduced in tunnel slit at late plantings because plants were grown under the film at the time of infection. The number of marketable ears was similar among all treatments except mulch at March 5 planting where BSDV was severely infected. Gross income was high in tunnel and tunnel slit at March 25 planting which had more larger marketbale ears and tunnel and tunnel slit at March 5 planting which had higher market price.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.211-216
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• 2003

The objective of this study was to determine the degradability of cassava chip (CC), cassava waste (CW), yellow sweet potato (YP), white sweet potato (WP), purple sweet potato (PP), corn meal (CM), and rice bran (RB) using in situ technique. Two ruminally fistulated steers with an average weight of $303{\pm}10kg$ were used to determine in situ degradabilities of DM and OM. Seven feed sources were weighted in nylon bags ($38{\mu}m$ pore size) and incubated ruminally for 1, 2, 4, 6, 8, 12, 24, and 48 h. The results showed that asymptote (a+b) and effective degradability (ED) of DM of energy sources ranked from the highest to the lowest; CC, YP, WP, PP, RB, CW, and CM (99.3, 92.5; 97.6, 87.9; 97.5, 87.9; 97.2, 87.8; 87.5, 63.6; 78.6, 63.0 and 81.7; 59.3, respectively) and for OM asymptote (a+b) and effective degradability (ED) were similar to those of degradation of DM (99.4, 93.4; 98.8, 89.8; 98.5, 89.4; 98.4, 88.1; 92.4, 65.8; 85.1, 66.9 and 83.6, 63.3, respectively). It was concluded that disappearance characteristic of CC was the highest and it may potentially facilitate the achievement of optimal ruminal availability of energy: protein especially with NPN for microbial protein synthesis.

• Korean Journal of Microbiology
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• v.49 no.2
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• pp.112-117
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• 2013

Wheat streak mosaic virus (WSMV), a member of the genus Tritimovirus in Potyviridae, severely impacts wheat and corn seed worldwide, but has yet to be detected in Korea, and hence, every effort should be made to prevent its introduction. To prevent WSMV from entering the country, it is necessary to prepare a specific, sensitive, simple, and fast detection method for routine application to plant quarantine procedures. For this reason, a two-step diagnosis system consisting of RT-PCR and nested PCR is being used for WSMV detection. In addition, a novel positive control was developed for use with the system. WSMV has been detected in seed sweet corn from Japan and seed wheat from USA by a two-step diagnosis system, the details of which are described in this study. After sequence analysis, similarities of 80.6 and 100.0% with other isolates were determined by BLAST. They showed the same topology, which was classified as 4 genotypes by various phylogenetic trees, using a poly protein encoding sequence amplification. In this analysis, WSMV-JSweet-corn2868 (JX845574) is classified as clade B, while WSMV-Uwheat1944-1 (KC754959) and WSMV-Uwheat1944-2 (KC754960) belong to clade D.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.4
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• pp.452-460
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• 1999

This study was conducted in order to investigate the quality characteristics of Salku Pyun which was made by using mungbean, potato, sweet potato and corn starches. The pH of salku juice was 3.45 to 3.50 and the brix of that was 7.0%. The water content and water activity of salku pyun with potato starch was highest. The result of sensory evaluation showed that appearance, flavor, overall quality were highest in the Salku Pyun made with potato starch while texture, taste were highest in the Salku Pyun made with mungbean starch. Mechanical properties of salku pyun with mungbean starch was significantly higher in adhesiveness, hardness, chewiness. Texture of sensory evaluation were positively correlated with springiness, hardness, and chewiness of mechanical measurement. The factors which affect the overall quality on sensory evaluation were texture quality, taste quality, hardness, color and springiness.

• Journal of Environmental Science International
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• v.32 no.5
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• pp.365-374
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• 2023

Eight years (2014-2021) of climate data were collected from an automatic weather observation system installed at the foot of Mt. Geumo in Chilgok, Gyeongbuk. Using these data, we investigated local bio-climatological indices (warmth index, WI; coldness index, CI; and effective accumulated temperature, EAT) of the mountain region adjacent to the Keimyung Dongyeong forest. The study area's WI and CI were 109.3℃ and -11.3℃ per month, respectively, averaged across 8 years. These values are indicative of an evergreen broad-leaved forest in the warm temperate climate zone, suitable for cultivating sweet persimmons and figs. Additionally, EAT in Dongyeong was 2,113.7℃, averaged across 8 years, suitable for growing crops such as corn, soybean, and potato.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.334-339
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• 1985

A sweet corn hybrid, Honey Bantam, was planted on 24 May, 1984 in a silty clay loam soil to investigate the effects of polyethylene(P.E.) mulch and different levels and placements of Nitrogen(N) on soil properties and sweet corn growth. A split-split plot design with three replications was employed; P.E. mulch and bare soil were main plot, N levele of 8, 12, 16, and 20 kg/10a were subplot, and band and broadcast of fertilizers were sub-subplots. At early growth stage soil temperature under P.E. mulch was higher than that in bare soil by 5-10$^{\circ}C$, but the differences decreased as plant growth advanced. Soil hardness increased with soil depth while P.E. mulch reduced soil hardness probably by holding high soil moisture. Soil pH decreased up to the 6th week after planting and then increased in bare soil, but it contineously decreased up to the 8th weeks under P.E. mulch regardless N levels and placements. Electrical conductivity(EC) of soil increased up to the 6th weeks after planting and then decreased in all treatments except broadcast of fertilizers under P.E. mulch where EC increased contineously. Generally, soil EC under P.E. mulch was higher than that in broadcast. Broadcast of fertilizers did not affect emergence of seedlings in all N levels under P.E. mulch and bare soil, but band of fertilizers at all N levels under P.E. mulch and higher levels of N in bare soil reduced emergence rate significantly. Percent stand was possitively correlated with soil EC and it strongly influenced the number of marketable ears. Plant growth was enhanced and silking date was earlier by 14-19 days under P.E. mulch compared to bare soil probably due to increased soil moisture, reduced soil hardness and higher soil temperature.

• Korean Journal of Food Science and Technology
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• v.9 no.2
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• pp.106-115
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• 1977

In order to study the baking properties of various composite flours, naked barley flour, corn flour, potato flour, and sweet potato flour were added to the hard wheat flour respectively in a ratio of 3 : 7. Using above composite flours, effects of glyceryl monosterate (GMS), sodium stearyl lactylate (SSL), calcium stearyl lactylate (CSL), xanthan gum (XG) and polysaccharide (PS) were also examined in terms of sedimentation test, viscosity by amylograph and baking test. The results are as follows: 1) Sedimentation value decreased in the order of hard wheat flour (58), corn flour (47), potato flour (46), sweet potato flour (33). and barley flour (23). Significant effects of additives were observed for all of flours as well as for the composite flours. The most prominant result of additives was obtained with the composite flour of barley and wheat. Among the additives, mixtures of GMS and SSL at 1% final concentration and that of GMS and SSL at the same concentration increased the sedimentation value considerably. No sedimentation measurement, however, was possible for XG since the compound was precipitated by acid during experiment of sedimentation. 2) Effects of additives on the viscosity were determined by amylograph. The mixtures of GMS 1%+SSL 1% and GMS 1%+CSL 1% increased gelatinization point,maximum viscosity and cooling viscosity. GMS 1%+XG 1% or GMS 1%+PS 1% showed less effects. 3) GMS 1%+CSL 0.5% increased the specific loaf volume of bread produced from the composite flour of naked barley and wheat, and appearance, taste and texture of the product were very similar to those of the standard bread produced from wheat flour. GMS 1%+SSL 0.5%, however, increased the loaf volume of bread produced from the composite flours of corn, potato and sweet potato, and wheat. No effects were obtained with XG and PS, except slight improvement of the texture of bread. 4) No specific loaf volume of bread produced from the composite flour of barley and wheat was increased when 1% of SSL, CSL, XG or PS was used separately.

• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.39-44
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• 1969

Discussions on the adequacy of present level of supply of fertilizers on the basis of the results obtained from experiments conducted on farmers' fields. 1. No differences have been found between present supply and optimum doses of nitrogen and phosphorus for rice except potash of which present amount of supply is 2.26kg/10a which is lower than the optimum dose by 1.90kg/10a. About 1.2% increase in the yield of paddy may be expected by increasing the level of potash to 4.2kg/10a. 2. Increasing the present supply of nitrogen, phosphorus and potash by 3.4, 4.7 and 3.3kg/10a, respectively for barley is required in order to increase its yield by 8.6%. 3. About 17% increase in the yield of wheat may be expected by increasing the supply of nitrogen, phosphorus and potash by 3.4, 3.9 and 6.4kg/10a. 4. An additional quantity of 7.5kg/10a of nitrogen, 6.4kg/10a of phosphorus and 7.5kg of potash on corn may incrase its yield by 45% 5. 8% increase in the yield of sweet-potato is expected when 3.8, 1.8 and 15.1kg/10a of additional nitrogen, phosphorus and potash, respecitvely is applied to the crop. 6. 21% increase in the yield of potato may arise with 0.6, 3.3 and 3.6kg/10a additional nitrogen, phosphorus and potash, respectively. 7. 15% increase in the yield of soybean may result with the application of 2.8, 1.9 and 2.9kg/10a additional nitrogen, phosphorus and potash, respectively. 8. The present quantity of fertilizer supply, it is necessary hereafter to supply fertilizer with attentions on such crops as corn, sweet-potato and white-potato etc. Needs to be revised in view of such crops as corn, sweet-potato and white-potato.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.192-197
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• 1989

Two sweet corn hybrids, 'Tanok l' and 'Golden Cross Bantam 70 (GCB 70)' were grown at five plant densities, of 4, 167. 5,556, 6,667. 8, 333, and 11, 111 plants per 10 ares, with or without tiller removal, to determine effects of tiller removal on growth and yield of sweet corn hybrids at various plant densities. Tillers were pulled when less than 15 cm tall. The number of tillers per plant linearly decreased as plant density increased. The two hybrids had similar plant height, ear length and diameter, ear weight and the number of ears per plant and 10 ares. Tanok 1 lodged approximately 20％ at above 8,333 plants per 10 ares, while GCB 70 did not lodge at all, at any plant density. Tanok 1 had higher leaf area index (LAI), ear and stover yields than GCB 70. Except for root lodging and LAI, hybrid x plant density interaction was not significant at 5％ probability level. Plant density did not affect silking data. Increasing plant density linearly increased plant height, LAI, and stover yield, but linearly decreased ear length, ear weight, and the number of ears per plant. Increase in LAI was greater in Tanok 1 than in GCB 70, with increasing plant density. The relationships between the number of ears and ear yield per 10 ares and plant density were Quadratic. The optimum plant density was estimated to be approximately 6500 plants per 10 ares, using the equation based on ear yield. Except for ear height and LA I, hybrid x tiller removal and plant density x tiller removal interactions were not significant. Hybrid x plant density x tiller removal interaction was not significant for any characters. When averaged over hybrids and plant densities, tiller removal reduced plant height and ear and stover yields by about 3, 10, and 16％, respectively, but did not significantly affect silking date, root lodging, ear length and diameter and the number of ears per plant and per 10 ares. The results indicate that the optimum plant density is approximately 6500 plants per 10 ares, regardless of tiller removal and tillers are not to be removed at any plant density.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.2
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• pp.140-145
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• 1985

Field experiments were conducted in Suwon in 1982 and 1983 to evaluate the effects of compost application, nitrogen (N) rate and split application of N on growth, yield and N uptake of sweet corn (Zea mays L.) grown under clear polyethylene mulching condition. Urea was banded at N rates of 0 (only in 1983), 5, 10, 15 and 20 kg per 10a with or without compost application of 1500 kg per 10a at planting. In 1982, half of N was sidedressed at the 5-6 leaf stage in case of 15, and 20 kg N per 10a. Compost application increased ear size and ear weight per 10a (10%). The number of ears per 10a markedly increased with an increase in N rates up to 10 kg per 10a but was not significantly affected by further increased N rates. Ear weight per 10a increased linearly as N rate increased from 0 to 20 kg per 10a without compost but increased greatly up to 10 kg N per 10a with compost application. Dry matter yield increased greatly up to 15, 10 kg N per 10a with and without compost application, respectively. Nitrogen uptake increased linearly from 8.1 to 18.8 kg per 10a with an increase in N rates from 0 to 20 kg per 10a. The optimum N rate appeared to be 10 to 15 kg per 10a based on ear number, ear weight and dry weight per 10a. There was no significant difference between basal and split applications of N in terms of ear size, and number and weight of ears per 10a.