• Korean Journal of Weed Science
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• v.12 no.3
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• pp.200-222
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• 1992

The results of recent researches for improvement of seedling stand in direct seeded rice on the dry paddy in Korea were summarized as the following ; a variety to be cultivated should be chosen the characteristics of high percentage germination under low temperature, shorter period of shoot emergence, and better growth of the mesocotyl and shoots. Meanwhile, there was 40% increase in seedling stand at the treatment of removal of the seed awn under using the drill seeder. After seeding the rice seed covered with soil of 3cm depth was better seedling emergence and also there was the hightest seedling emergence at the 70% of moisture content of the soil. In addition, the application of the Release containing GA 10% enabled to increase the seedling stand and furthermore it was effective under deep seeding depth. The optimum seeding date should be seeded around May 10 when mean air temperature is above 12-13$^{\circ}C$ so that may establish more less 70% in seedling stand. Based on an appropriate seedling stand of 150/$m^2$, the optimum seeding rate was 5kg/10a. It was the best in seeding method using drill seeder and the most desirable recommended seeding method was the drill seeder in terms of seedling stand. In order to improve seedling stand water management was more effective in canal irrigation and in drainage at 6hr after irrigation following by the seeding process. On the other hand, for the increase of seedling stand under flooded condition a variety might have characters being better germination at low concentration of dissolved oxygen and vertically deeper growing of the crown root. Also, seedling stand was able to increase with the seed coating of $CaO_2$in the flooded soil. It was possible to be seeded on the early part of May being mean air temperature of avove 10$^{\circ}C$ and the optimum seeding rate was 5kg/10a. For an effective water management water would be flooded up to 3cm depth for 2-3 weeks after seeding. The rice plant grown under the direct seeded cultivation might be not so much strong in lodging resistance compared to that grown under the transplanting and moreover direct seeded rice cultivation under flooded condition would be more weak growth of the rice plant than that on dry paddy. Meanwhile, the lodging would be affected by the seeding rate, the soil depth after seeding. and seeding method even in the same variety. In particular, roots in the lodging pattern of direct seeded rice cultivation under flooded condition were largely distributed on the soil surface so that resulted easily in the lodging. In general, the lodging resistance would be greater as seeding rate and amount of N fertilizer application are lower and soil depth after seeding is higher. Among the introduction of different seeding method the high ridged drill seeding method on dry paddy soil resulted in the lowest in the lodging index and also it was lower in the drill seeding method than in the scattering seeding method under flooded condition. In case of more than 150 seedlings per $m^2$ there was a severe lodging due to high lodging index at the 3rd and 4th internodes. The effective lodging prevention was able to at the treatment of the Inabenfide at 45 days before heading and the Uniconazol at 15 days before heading which caused the shortage by 10-15cm in culm length. Also, fertilizer management using split application of nitrogen would be contributed the reduction of lodging at the rate of 20-30-20-20-10%(basal-5th leaf stage-7th leaf stage-panicle initiation stage-heading stage) on the dry paddy soil.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.207-216
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• 2004

This study was carried out to select the promising forage crops for forage production in paddy field of NLRI, RDA, Suwon from 1999 to 2001. The species of forage crop used in this experiment were barley(3 varieties), wheat(2), rye(3) and Italian ryegrass(IRG, 3). Stages of heading, milk and yellow ripe of barley were 1 May, middle May and late May, respectively. In milk to yellow ripe stage, dry matter(DM) and total digestible nutrient(TDN) yield of barley were $7.30{\sim}9.58$ MT and $4.75{\sim}6.24$ MT per ha, and Albori was the most promising variety among the barley. The growth of wheat was a little late compared to that of barley. but it seemed to be crop having higher forage yield and nutritive value. In milk to yellow stage, DM and TDN yield of wheat were $8.17{\sim}10.82$ MT and $5.33{\sim}7.31$ MT per ha. Heading stage of rye was 27 to 29 April, and it seemed to be suitable for harvest at heading to flowering stage because of heavy lodging after flowering. In flowering stage, DM and TDN yield of rye were 10.18 and 6.03 MT per ha. Heading stage of early maturing IRG was 7 May and it seemed to be good for harvest at flowering stage of middle May in cropping system. In flowering stage, DM and TDN yield of early type IRG were 4.48 and 2.96 MT per ha. The results demonstrated that the promising forage crops for forage production in paddy. field were rye and barley(Albori) in Middle region, and rye harvesting at early May was recommended when considered middle May of rice transplanting period, and rye and barley considered late May of rice planting period. Also early maturing and high yielding IRG variety was strongly needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.79-86
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• 1973

In order to investigate the heading responses of naked barleys and their grain yields under the different sowing times in spring sowing at 9 levels and to select the promising variety, present work was carried out with 11 recommended naked barley varieties and 2 newly developed lines for the period of 3 years from 1971 to 1973 at Iri, these results being summarized as follows: 1. Under spring sowing cultures, 'Wanju naked barley' being spring habit showed the highest yields among them. However, Sedohadaka and Bangju being winter habit were also considered as the promising varieties. 2. In the case of sowing the spring type naked barleys in spring the optimum sowing time of barleys at Iri was estimated in the late of February or the early of March. 3. The number of main culm leaves and tillering per hill of 'Wanju naked barley' were not influenced at sowing times. But winter type barleys being sown in spring, they were outstandingly increased in accordance with the sowing time being late, especially after the critical sowing time. 4. In comparison with average days from germinating to heading date under different seasonal sowing at the same variety, 'Wanju naked barley' took 64.4 days to get heading and Kikaihadaka and Hyangchoen gwa, the low spring growing habit varieties, 72-73 days. 5. Young spikelet differentiation stage (length of young spikelet: 0.3-0.5mm) arrived at about 30 days before heading date in comfortable sowing time without regarding spring or winter type. But number of main culms disclosed great differences among them; barleys being high spring type were 4 leaves and low about 6. 6. In the view of morphology, culm length under the different seasonal sowing could not be found out differences in the high spring type barleys, but in the low, it was grately shortened by postponing the sowing time. The barley height of rosette form had no difference at any sowing time.difference at any sowing time.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.264-270
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• 2017

This study was carried out to investigate the optimal harvesting time, feed value and fermentation quality of barley and wheat for the making of chopped whole crop silage substitute for formula feed. As a result, the moisture content of barley and wheat decreased with a late harvest, and barley progressed faster than wheat. The plant height was similar with harvesting time, and the number of spikes decreased with prolonged period after heading. The dry matter yield and TDN yield of barley harvested at 35 and 40 days after heading were significantly higher than those at 30 days after heading and wheat was significantly higher at 40 and 45 days than at 35 day after heading(p<0.05). Crude protein content of barley and wheat were increased with later harvesting time, and crude fiber, crude fat and crude ash were slightly decreased, but not statistically significant. NDF and ADF content of barley decreased with later harvesting time, and those showed similar level in wheat. TDN content of barely was slightly increased but there was no difference in wheat. Comparing the effects of fermentation on feed value of chopped whole crop silage, the approximate compositions were slightly increased after fermentation, but the difference was not significant. Fermentations resulted in increasing the pH value of barley silage with late harvesting time, but decreasing the lactic acid content(p<0.05). A pH value of wheat silage showed similar level in different harvest time, and lactic acid content was decreased. Considering the quantity and quality of fermentation, barley and wheat can be used for making chopped silage of whole crop silage when they were harvested at 35 days and 40~45 days after heading, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.195-202
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• 1995

This experiment was performed to characterize the optimum water table level for the growth and yield of barley(var. Olbori) and wheat(var, Grumil), Olbori and Grumil were grown in the 550 liter plastic pot filled with silt loam or sandy loam, During the whole growth period, the water table adjusted to be 20, 30, 40, 50, and 70cm, Higher water table was resulted in the decrease in plant height and top dry weight, but in the increase of the ratio of top to root dry weight, especially in barley, This suggested that high water table level affected more the growth of top than that of root, The number and area of green leaves were decreased as the water table was higher than 30 to 40cm at the late growth period(May 18, 1993), The largest number and area of green leaves were shown at 50cm of water table in sandy loam and at 70cm in silt loam, As the water table was high, the leaf chlorophyll content was low, And barley was affected more significantly than wheat by soil texture, The photosynthetic activity was decreased remarkably at 20cm water table, Heading period was 2 to 3 and 4 days earlier at the 20cm water table of sandy loam in barley and wheat, respectively, However this earlier heading was not shown in silt loam, Grain filling was accelerated 5 to 7 days earlier in barley and 10 days in wheat grown at 20cm water table, The highest yield was present at 50 and 70cm water table, The yield was decreased remarkably at 20cm water table, resulting that yield reduction ratio of barley was 71.1% and 72, 2%, and that of wheat was 41.0% and 60, 0% in sandy loam and silt loam, respectively, High water table decreased the number of spike per unit area, but increased the seed weight per spike in barley, However, High water table reduced the seed weight per spike in wheat. There was significant correlation between yield and leaf chlorophyll content in wheat and barley, Yield was correlated significantly with green leaf area in barley, and with top dry weight, ratio of top to root dry weight chlorophyll content and photosynthetic activity in wheat. The optimum water table was 50 to 70cm in wheat and barley, They grew fairly well at 30cm water table of sandy loam, and at 40cm of silt loam.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.212-220
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• 1995

The optimum seeding date and the suitable seeding period for puddled drill seeding of rice at southern plain area were determined by using Sinunbongbyeo (early maturing variety), Hwaseongbyeo(medium maturing var.) and Dongjinbyeo (late medium maturing var.) at National Honam Agricultural Experiment Station from 1993 to 1994, Seedling stand was decreased significantly at seeding on April 25 in all varieties, Threshold seed-ing dates for stable ripening was estimated as June 10 in Sinunbongbyeo, May 31 in Hwaseongbyeo and May 25 in Dongjinbyeo, The 1,000 grain weight and the ripened grain rate were highest at seed-ing on May 10 or May 25 in all varieties, and decreased significantly at seeding on June 25 in Sinunbongbyeo and seeding after June 10 in Hwaseongbyeo and Dongjinbyeo, The optimum average air temperature for 40 days after heading was 22.6$^{\circ}C$ for highest ripening rate and 22.0$^{\circ}C$ for heaviest 1,000 grain weight. The optimum seeding date for highest yield was May 9 in Dongjinbyeo, May 13 in Hwaseongbyo and May 15 in Sinunbongbyeo.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.208-214
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• 2016

This study was conducted to evaluate the effects of different sowing times (May 25, June 10, June 25, July 10, and July 25) on growth and yield of four proso millet (Panicum miliaceum L.) cultivars (Hwanggeumkijang, Manghongchal, Ibaekchal, and Hwangsilchal) at a cultivation area in Iksan, Jeonbuk Province. Heading and ripening times were delayed, with later sowing times in all cultivars, and the periods for heading and ripening were shortened. For sowing from May 25 to July 25, the growth stage was shorter by 40 days in Manghongchal, 38 days in Hwanggeumkijang, 36 days in Hwangsilchal, and 30 days in Ibaekchal. The culm length, ear length, ear width, and culm diameter differed significantly between the cultivars and sowing times. In particular, the culm and ear lengths were considerably reduced when the sowing time was delayed. The grain yield (kg/10a) of Hwanggeumkijang and Ibaekchal was 312 and 359 kg, respectively, for sowing on June 10; and that of Manhongchal and Hwangsilchal was 286 and 404 kg, respectively, for sowing on June 25. Thus, the optimum sowing time was June 25 for Hwanggeumkijang and Ibaekchal, and June 10 for Manhongchal and Hwangsilchal.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.4
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• pp.283-289
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• 2016

This study was carried out to identify the optimum seeding dates for selecting a double-cropping system and to assess the effect of polyethylene film mulching on the yield of Proso millet. Seeds of the varieties Hwanggeumgijang and Ibaegchal were sown in Miryang on five different dates: 1st (May 25), 2nd (June 15), 3rd (June 25), 4th (July 5), and 5th (July 15), with and without polyvinyl mulching. The varieties have different characteristics, for example, Hwanggeumgijang is an early-maturing type and more sensitive to temperature, whereas Ibaegchal is a medium-maturing type and more sensitive to the duration for which it is exposed to sunlight. Late-sown Hwanggeumgijang had a short heading date from seeding and required a low accumulated temperature. It also had a shorter period of heading, a shorter culm length and a shorter diameter of stem. In contrast, it had had a higher number of ears $per\;m^2$ although similar ear length and similar 1000-grain weight. The yield potential of Hwanggeumgijang was found to decrease at a late seeding date. In particular, it significantly decreased at the seeding date of July 15. In the case of cultivation with polyvinyl mulching, the period of heading was shorter by 2-4 days and the yield potential was increased by approximately 12-32%. The length and diameter of culm in Ibaegchal were slowly decreased, but the length of ear, the 1000-grain weight and the yield potential were similar for all seeding dates (except July 15) and cultivation with and without mulching. When sown late, the length and diameter of the culm of Ibaegchal very rapidly decreased by the July 15 seeding date. The protein content of Ibaegchal was higher but the amlyose content of Ibaechal was lower compared to Hwanggeumgijang. At late seeding dates, the protein contents of the two varieties increased but the amylose contents were similar.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.34-44
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• 1989

The stability of rice cultivation in Korea is largely depended on climatic conditions, especially, low temperature at the period of early growth stage and after heading. The improvement of cold tolerant varieties and appropriate cultural practices in rice are very effective to minimize the cold damage. This paper is summarized the mechanism and counterplans of cold injury of rice plants. The paddy area having commonly cold injury in Korea is approximately 15, 522ha in 1,709 sites on the national scale. The cold damage at seedling stage in nursery bed appeared to poor germination, leaf discoloration, dead seedlings and seedling rot ect.. At the vegetative stage, the decreased tiller number due to poor rooting and the delayed heading caused by slow growth and panicle differentiation are commonly showed. The cold injury at early reproductive stage appeared to the degeneration of spikelets and rachis - branches, while that at meiosis stage showed to increased sterility due to poor development of pollen and shortened panicle length with delaying heading, therefore the grain yield is largely decreased. The cold damage at heading and ripening stages showed to poor pollination and fertilization, low panicle exsertion, poor grain filling and finally grain quality became low. To minimize the cold injury to rice plants by low temperature, following counterplans would be recommonded ; Improvement of the cold toelrant rice varieties for the regions of midmountains and alpines. Raising healthy seedlings at upland nursery beds and by using of growth regulators such as ABA, Fuchiwang and Tachiace. Soil improvement and organic matter application to reduce cold damage by increasing water and fertilizer holding capacities in the paddy field having commonly cold water and in the place where cold damage is regularly occurred. Appropriate fertilization for raising healthy rice plants to tolerate under low temperature condition. Water management to increase water temperature in the paddy such as depth watering, round channels and polyethylene tubes around the field. Establishment of the optimum cultivation time of rice based on minimum, mean and maximum temperatures at different regions with appropriate rice varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.404-412
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• 2011

This experiment was conducted to clarify the effect of the temperature for grain filling duration on quality and taste of cooked rice cultivated in different region in Korea. In 2006 and 2007, 4 mid-late maturing group of rice varieties (Nampyeongbyeo, Ilpumbyeo, Junambyeo and Dongjin 1) were cultivated in 28 experimental plots of 27 different regions located in 8 provinces. The taste of cooked rice were positively correlated with 1,000 grain weight but negatively correlated with protein content of brown rice. Mean temperature for 30 days from heading was more closely correlated with grain filling and tastes of cooked rice than those for 40 days. Though, the optimum mean temperature for the best taste of cooked rice for 30 days after heading was 22.1 to $23.1^{\circ}C$ depending on varieties, in general, 1,000 grain weight and cooked rice taste were the highest in the mean temperature of $22.2^{\circ}C$ for 30 days from heading. But grains were poorly ripened in case of the mean temperature lower than $21.0^{\circ}C$ for 30 days after heading. Therefore, for the better taste of cooked rice in Korea, the developing new rice varieties and cultivation method should be focused to adjust the mean temperature within $22-23^{\circ}C$ during the period of 30 days after heading.