• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.4
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• pp.339-349
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• 2010

The uses of the polypropylene bulk bags having the loading capacities more than 500 kg are increasing in Korea recently as a storage container for rough rice. This study was performed to obtain the basic information on the changes of temperature and relative humidity in the bulk-bag-stored high moisture rough rice during waiting for drying. At the moisture content more than 22% on wet weight basis of paddy, the bulk-bag inside temperature rose up to more than $40^{\circ}C$ and then slid down during storage. For example, in case of Hwaseongbyeo, 26.5% moisture content of rough rice (MCRR) harvested at 46 days after heading (DAH) showed $54.5^{\circ}C$ of peak temperature at 66.8 hours after bulk-bag loading, 22.5% MCRR harvested at 52 DAH exhibited $42.0^{\circ}C$ at 81.1 hours, and 19.7% MCRR harvested at 55 DAH displayed $38.9^{\circ}C$ at 119.0 hours. There were a good linear relationship between peak temperatures of bulk-bag inside and moisture contents of paddy ($r^2$=0.89 in 2005, and 0.87 in 2006), while the slope and intercept of the linear regression equation was affected by the environmental conditions such as ambient temperatures and microbial flora. The peak temperatures increased with the rate of about $2.74-3.33^{\circ}C$ per every 1% increase of moisture content at higher moisture contents of paddy than 19%. The relative humidity varied depending on bulk-bag inside temperature and rough rice moisture content, and showed the range of 94.2% to 99.9% in the central point of the bulk-bag. The results suggested that a rapid drying treatment as soon as possible was needed to produce a good quality of rice when the paddy of high moisture more than 22% on wet basis was harvested in a bulk-bag especially at high ambient temperature.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.50-56
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• 2015

Italian ryegrass is generally cultivated by a winter forage in a paddy field, the harvest season overlaps with rice transplantion in some cases. In addition, farmers can miss the optimal seedtime for Italian ryegrass because of the rainy season. Therefore, this research was conducted between October 2012 and June 2013 in Kwangjin, Korea to examine the effect of spring-seeding on the yields and quality of Italian ryegrass for the determination of an alternative if the optimal seedtime is missed. This trial consists of four different seeding dates (15 February, 25 February, 5 March, and 15 March) and three varieties (Kowinmaster, Kowinearly, and Green farm). The Italian ryegrass varieties "Kowinmaster," "Kowinearly," and "Green farm" were sown on February 15. The heading date of each variety showed from May 12 to May 9 and interval time of five days but the Treatment of March 15 planting date showed three days interval. The Kowinmaster variety, planted on February 15, was 93.0 cm taller on March 15 with a height of 105.7 cm. The Kowinearly and Green farm varieties planted on February 15 were of a similar height on February 25 and received a poor lodging score when planted quickly. The dry matter (DM) yield of the Kowinearly planted on February 15 was high but that of Green farm was low at 6,609 kg/ha and a difference was not shown between the varieties. The DM yield was different for those varieties planted on February 15 and March 15 (P<0.05). The crude protein content (CPC) of those varieties planted on February 15 showed an average of 8.8%, while those that were planted on March 15 showed an average that was about 2.3% higher at 11.1%; furthermore, the latter also showed lower acid detergent fiber (ADF) and total digestible nutrient (TDN) contents, by 2.1% and 1.5%, respectively. The relative feed value was about 5.9% higher, depending on the seeding date, as well as being slower and showing less difference between the varieties. According to this study, Italian ryegrass planted in a paddy field of the southern region of Korea on February 25 will produce a high-quantity yield with nutritive value.

• Research in Plant Disease
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• v.14 no.3
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• pp.143-152
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• 2008

Mixed-planting of two rice cultivars, HP ('Hopyeongbyeo') and NP ('Nampyeongbyeo'), having a dissimilar susceptibility to rice blast was practiced for chemical-free control of rice blast in the field. The HP/NP combination was selected for applying under mechanized agricultural conditions. Because they have similar genetic characteristics such as seed germination and heading time, culm length, rice quality and size of rice grains except susceptibility to blast. Incidence of panicle blast was reduced 50.4 % compare with supposed blast incidence by HP/NP mixed-planting when the seeds of two cultivars were combined 1 to 1 as weight. Supposed blast incidence was estimated from reduction of rice blast caused by addition of a resistant cultivar NP. Race diversity of Magnaporthe oryzae was examined for correlation with control effect of HP/NP mixed-planting on rice blast. The population of dominant race KJ-101 was diminished and replaced with various co-existing races and eleven new races were appeared in mixed-planting plot. Total number of race isolated from mixed-planting plot was not largely different from mono-culture. However, detection frequency of the new race was increased and variation of the population size of each race was decreased in mixed-planting plots. It was shown that a biased community with a dominant race (KJ-101 or KI-181) was altered to a balanced one of coexisting races. From these results, it was supposed that the balanced diversity among co-existing races within a community might be correlated to control effect by HP/NP mixed-planting on rice blast. Further more, it should be studied that genetic characteristics of the individual race including a virulence on cv. HP and NP was examined for verifying a correlation of mixed-planting effect and race diversity.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.143-150
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• 1983

Red rice (local name "Sore") as a weed has been a serious threat to rice production in direct-seeded rice culture in Ganghwagun, Gyeonggi province. In the Ganghwagun 508 ha out of 1,420 ha in the Samsanmyeon area is infested with red rice. The average lowland rice yield is about 4,300 kg/ha in the Ganghwagun, but the average upland rice yield is about 2,000 kg/ha in infested area. This study was carried out in order to clarify the ecological characteristics of red rice and factors affecting the competitive ability of five red rice varieties, collected from Samsanmyeon in 1981, with rice cultivar. Five varieties-Monggeunsare, Salsare, Ginkaragsare, Galsaegsalsare, Galsaegkaragsare-showed the same morphological characteristics of cultivated Japonica type, Chuncheongbyeo, but red rice tillers more profusely, is taller and lodges more easily than Chucheongbyeo. It shatters easily about 10-15 days after heading date, and at this time the hull is discolored in yellow or dark brown. There are many types of red rice with short or long owns on the spikelet, occasionally with or without own on the spikelet in the same hill, and the grains are short or long. In red reice leaf blast occurs more severely than in cultivated Indica/Japonica type, Teabaegbyeo, particulary serious in Monggeunsare. When red rice invaded in direct-seeded rice, number of panicles of rice became reduced more than other yield components.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.2
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• pp.87-93
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• 2014

Multiple cropping system is an important agricultural system in Korea, which is significant to increase forage yield and promote agricultural economic development. This experiment was carried out to develop triple cropping systems (winter cereals crop for forage - silage corn - summer oats) for maximum year-around forage production at paddy field in southern region. We also to select a winter forage crop to determine corn planting time, and to examine the forage productivity and feed value of summer cultivated oat, which was planted after corn cultivation. When winter cereal crops for forages are harvested in accordance with and corn planter, the fresh yield and dry matter yield of rye were 32.0 ton/ha and 5.8 ton/ha, respectively, showing higher yielding compared to other winter crops. Corn silage as summer crop was showed the fresh yield and dry matter yield of 72.1 ton/ha and 20.2 ton/ha, respectively. In the feed value, crude protein and TDN contents were 7.4% and 69.3%, respectively. They was showed higher productivity and feed value. The heading date of High-speed oat was October 10, and its fresh yield and dry matter yield were 37.6 ton/ha and 8.0 ton/ha, respectively. As a feed value, crude protein and TDN content was 11.4% and 59.1%, respectively. Therefore, triple cropping systems for the production of forage all throughout the year are possible with the introduction of summer oats in the southern region, and rye could be the most suitable winter forage crops for triple cropping systems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.344-352
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• 2019

Drought stress caused by global climate change is a serious problem for rice cultivation. Increasingly frequent abnormal weather occurrences could include severe drought, which could cause water stress to rice during the seedling stage. This experiment was conducted to clarify the effects of drought during the seedling period on yield and quality of rice. Drought conditions were created in a rain shelter house facility. The drought treatment was conducted at 3, 10, and 20 days after transplanting. Soil water content was measured by a soil moisture sensor during the whole growth stage. In this study, we have chosen 3 rice cultivars which are widely cultivated in Korea: 'Haedamssal' (Early maturing), 'Samkwang' (Medium maturing), and 'Saenuri' (Mid-late maturing). The decrease in yield due to drought treatment was most severe 3 days after transplanting because of the decrease in the number of effective tillers. The decrease in grain quality due to drought treatment was also most severe 3 days after transplanting because of the increased protein content and hardness of the grains. The cultivar 'Haedamssal' was the most severely damaged by water stress, resulting in about a 30% yield loss. Drought conditions diminished the early vigorous growth period and days to heading in early-maturing cultivars. The results show that drought stress affects yield components immediately after transplanting, which is a decisive factor in reducing yield and grain quality. This study can be used as basic data to calculate damage compensation for drought damage on actual rice farms.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.308-313
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• 2008

"Jeokjoong", a white winter wheat (Triticum aestivum L.) variety was developed from the cross "Keumkang"/"Tapdong". "Jeokjoong" is an awned, semi-dwarf and soft white winter wheat, similar to "Keumkang" (check variety). The heading and maturing date of "Jeokjoong" were similar to "Keumkang". Culm and spike length of "Jeokjoong" were 78 cm and 7.5 cm, similar to "Keumkang". "Jeokjoong" had lower test weight (800 g) and lower 1,000-grain weight (40.1 g) than "Keumkang" (811 g and 44.0 g, respectively). It had resistance to winter hardiness, wet-soil tolerance and lodging tolerance. "Jeokjoong" showed moderate to scab in test of specific character although "Keumkang" is susceptible to scab. "Jeokjoong" had lower flour yield (69.2%) and ash content (0.36%) than "Keumkang" (72.0% and 0.41%, respectively) and similar flour color to "Keumkang". It showed lower protein content (8.9%) and SDS-sedimentation volume (36.8 ml) and shorter mixograph mixing time (3.5 min) than "Keumkang" (11.0%, 59.7 ml and 4.5 min, respectively). Amylose content and pasting properties of "Jeokjoong" were similar to "Keumkang". "Jeokjoong" had softer and more elastic texture of cooked noodles than "Keumkang". Average yield of "Jeokjoong" in the regional adaptation yield trial was 6.19 MT ha-1 in upland and 5.33 MT/ha in paddy field, which was 19% and 16% higher than those of "Keumkang" (5.21 MT/ha and 4.58 MT/ha, respectively). "Jeokjoong" would be suitable for the area above the daily minimum temperature of $-10^{\circ}C$ in January in Korean peninsula.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.44-50
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• 2009

"Sukang", a winter wheat (Triticum aestivum L.) cultivar was developed by the National Institute of Crop Science, RDA. It was derived from the cross "Suwon266" / "Asakaze" during 1994. "Sukang" was evaluated as "Iksan312" in Advanced Yield Trial Test in 2005. It was tested in the regional yield trial test between 2006 and 2008. "Sukang" is an awned, semi-dwarf and hard winter wheat, similar to "Keumkang" (check cultivar). The heading and maturing date of "Sukang" were similar to "Keumkang". Culm and spike length of "Sukang" were 90 cm and 8.1 cm, longer culm length and similar spike length compared to "Keumkang" (80 cm and 7.9 cm, respectively). "Sukang" had similar test weight (819 g/L) and lower 1,000-grain weight (40.2 g) than "Keumkang" (813 g/L and 44.9 g, respectively). "Sukang" showed resistance to winter hardiness and pre-harvest sprouting, which lower withering rate on the high ridge (4.5%) and rate of pre-harvest sprouting (0.2%) than "Keumkang" (21.9% and 30.4%, respectively). "Sukang" had lower flour yield (71.1%) and higher ash content (0.45%) than "Keumkang" (74.1% and 0.42%, respectively). "Sukang" showed lower lightness (89.13) and higher yellowness (10.93) in flour color than "Keumkang" (90.02 and 9.28, respectively). It showed higher protein content (12.8%) and gluten content (11.1%) and lower SDS-sedimentation volume (56.8 ml) and mixing time of mixograph (2.6 min) than "Keumkang" (11.9%, 10.2%, 62.3 ml and 4.7 min, respectively). Fermentation properties, amylose content and pasting properties of "Sukang" were similar to "Keumkang". "Sukang" showed different compositions in high molecular weight glutenin subunits (HMW-GS, $2^{\ast}$, 13+16, 2+12) and puroindolines (pina-1b/pinb-1a) compared to "Keumkang" ($2^{\ast}$, 7+8, 5+10 in HMW-GS and Pina-1a/Pinb-1b in puroindolines, respectively). "Sukang" showed lower hardness (4.53 N) and similar springiness and cohesiveness of cooked noodles (0.94 and 0.63) compared to "Keumkang" (4.65 N, 0.93 and 0.64, respectively). Average yield of "Sukang" in the regional adaptation yield trial was 5.34 MT/ha in upland and 4.72 MT/ha in paddy field, which was 4% and 1% lower than those of "Keumkang" (5.55 MT/ha and 4.77 MT/ha, respectively). "Sukang" would be suitable for the area above $-10^{\circ}C$ of daily minimum temperature in January in Korean peninsula.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.225-233
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• 2019

This study was conduct to investigate the effect of mixed seed sowing and flour blending on the uniformity of flour quality of Korean domestic wheat. Two wheat varieties (Keumkang and Baegjoong) were selected for sowing mixed seeds, and their growth characteristics and flour quality were analyzed. Quality of flour blending with the same varieties was also evaluated. The ratios for mixed seed sowing and flour blending were from 0 to 100% with a 10% increase of interval for each treatment. On increasing the portion of Baegjoong in mixed seed sowing, the heading time was a little delayed, however, yield increased. The results of the flour quality showed lower damaged starch content and sodium carbonate SRC (solvent retention capacity) value for Keumkang than for Baegjoong. Protein quantity by protein content and quality by SDSS (Sodium Dodecyle Sulfate-Sedimentation) volume, lactic acid SRC, and mixograph pattern of Keumkang were superior to those of Baegjoong. Compared with mixed seed sowing, overall quality characteristics of flours with different ratios showed predictable and proportional change by flour blending. This demonstrated the successful application of flour blending, compared with mixed seed sowing, for improving the uniformity of flour quality.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.130-136
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• 2009

"Hanbaek", a white winter wheat (Triticum aestivum L.) cultivar was developed by the National Institute of Crop Science, RDA. It was derived from the cross "Shan7859/Keumkang"//"Guamuehill" during 1996. "Hanbaek" was evaluated as "Iksan314" in Advanced Yield Trial Test in 2005. It was tested in the regional yield trial between 2006 and 2008. "Hanbaek" is an awned, semi-dwarf and hard winter wheat, similar to "Keumkang" (check cultivar). The heading and maturing date of "Hanbaek" were similar to that of "Keumkang". Culm and spike length of "Hanbaek" were 89 cm and 9.0 cm, which longer culm length and spike length than "Keumkang" (80 cm and 7.9 cm, respectively). "Hanbaek" had lower test weight (797 g) and higher 1,000-grain weight (47.7 g) than "Keumkang" (813 g and 44.9 g, respectively). "Hanbaek" showed resistance to winter hardiness and susceptible to pre-harvest sprouting, which lower withering rate on the high ridge (4.4%) and higher rate of pre-harvest sprouting (47.9%) than "Keumkang" (21.9% and 30.4%, respectively). "Hanbaek" had similar flour yield (74.4%) to "Keumkang" (74.1%) and higher ash content (0.45%) than "Keumkang" (0.42%). "Hanbaek" showed lower lightness (89.13) and similar redness and yellowness (-0.87 and 10.93) in flour color than "Keumkang" (90.02, -1.23 and 9.28, respectively). It showed similar protein content (12.8%) SDS-sedimentation volume (63.0 ml) and gluten content (10.8%) to those of "Keumkang" (11.9%, 62.3 ml and 10.2%, respectively). It showed lower water absorption (59.6%) and mixing time (3.8 min) in mixograph and higher fermentation volume (1,350 ml) than those of "Keumkang" (60.6%, 4.7 min and 1,290 ml, respectively). Amylose content and pasting properties of "Hanbaek " were similar to those of "Keumkang". "Hanbaek" showed same compositions in high molecular weight glutenin subunits (HMW-GS, 2*, 13+16, 2+12), granule bound starch synthase (Wx-A1a, Wx-B1a, and Wx-D1a) and puroindolines (Pina-D1a/Pinb-D1b) compared to "Keumkang". "Hanbaek" showed lower hardness (4.22N) and similar springiness and cohesiveness of cooked noodles (0.94 and 0.63) to those of "Keumkang" (4.65N, 0.93 and 0.64, respectively). Average yield of "Hanbaek" in the regional adaptation yield trial was 5.98 MT/ha in upland and 5.05 MT/ha in paddy field, which was 8% and 6% higher than those of "Keumkang" (5.55 MT/ha and 4.77 MT/ha, respectively). "Hanbaek" would be suitable for the area above the daily minimum temperature of $-10^{\circ}C$ in January in Korean peninsula.