• Title/Summary/Keyword: Direct water-seeded culture

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Optimum Number of Seedling Stands of Rice for High Yield in Direct Water-Seeded Culture (벼 담수직파재배에 있어서 적정립모수 설정)

  • 이철원;성기영;임준택
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.39 no.5
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    • pp.405-411
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    • 1994
  • This study was carried out to determined the optimum seeding rate and number of seedling stands per unit area for high yield with two varieties of rice, Nakdongbyeo (Japonica type) and Samgangbyeo (Indica x Japonica type), in direct water-seeded rice culture at Crop Experiment Station. Seeds coated with $CaO_2$ after germination were sowed at May 4 in 7 levels, such as 1.6, 1.8, 2.1, 2.7, 3.5, 4.0, 4.3kg /10a, and the number of seedling stands per square meter was adjusted to be 30, 40, 60, 80, 100, 120, 140 plants, respectively. The maximum number of tillers increased as the seeding rates increased, but the ratio of effective tillers decreased. The critical dates of effective tillering of tested varieties were delayed by the lower seeding rates, and the date was June 18 at the plot of seeding rate with 3.5kg /10a. The number of panicles per unit area increased in accordance with the increased seeding rates. The number of spikelets per panicle in Nakdongbyeo was not affected by the seeding rates, but in Samgangbyeo it decreased as the seeding rate increased. The optimum number of seedling stand per square meter appeared to be 78 in Nakdongbyeo and 120 in Samgangbyeo, respectively. It meant that the optimum seeding rates for Nakdongbyeo and Samgangbyeo were about 2.7 and 4.0kg /10a, respectively.

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Seedling Stand Influenced by Water Management after Seeding and Seed Soaking with Plant Growth Regulators in Direct Wet Seeding Rice

  • Back, Nam-Hyun;Kim, Sang-Su;Kang, Si-Yong;Choi, Min-Gyu;Shin, Hyun-Tak;Kwon, Tae-Oh
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.3
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    • pp.225-229
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    • 1999
  • Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA$_3$) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.

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Rapid Quantification of Salmonella in Seafood Using Real-Time PCR Assay

  • Kumar, Rakesh;Surendran, P.K.;Thampuran, Nirmala
    • Journal of Microbiology and Biotechnology
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    • v.20 no.3
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    • pp.569-573
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    • 2010
  • A quantitative detection method for Salmonella in seafood was developed using a SYBR Green-based real-time PCR assay. The assay was developed using pure Salmonella DNA at different dilution levels [i.e., 1,000 to 2 genome equivalents (GE)]. The sensitivity of the real-time assay for Salmonella in seeded seafood samples was determined, and the minimum detection level was 20 CFU/g, whereas a detection level of 2 CFU/ml was obtained for pure culture in water with an efficiency of ${\geq}85%$. The real-time assay was evaluated in repeated experiments with seeded seafood samples and the regression coefficient ($R^2$) values were calculated. The performance of the real-time assay was further assessed with naturally contaminated seafood samples, where 4 out of 9 seafood samples tested positive for Salmonella and harbored cells <100 GE/g, which were not detected by direct plating on Salmonella Chromagar media. Thus, the method developed here will be useful for the rapid quantification of Salmonella in seafood, as the assay can be completed within 2-3 h. In addition, with the ability to detect a low number of Salmonella cells in seafood, this proposed method can be used to generate quantitative data on Salmonella in seafood, facilitating the implementation of control measures for Salmonella contamination in seafood at harvest and post-harvest levels.

Reasonable Seeding Rate for Ridge Direct Seeding on Dry Paddy of Rice as an Irrigation Water-Saving Cultural System (벼 휴립건답직파 절수재배에 알맞은 파종량)

  • Choi Weon-Young;Park Hong-Kyu;Kim Sang-Su;Shin Hyun-Tak;Choi Sun-Young
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.2 no.4
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    • pp.143-147
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    • 2000
  • This study was conducted to investigate suitable seeding rate under irrigation water-saving rice culture in ridge direct seeding on dry paddy during 1997~1998. Dongjinbyeo was seeded from 60 kg/ha to 120 kg/ha on silty loam condition. The number of irrigation from 3-leaf stage to complete drainage were 7.5 times and total amount of irrigation was 258.75 mm. The number of seedling stand rose with the increase of seeding rate, whereas the rate of seedling stand was decreased with the increase of it. Soil moisture tension was -2kPa at one day after stopped irrigation and lowered to -30kPa at five days after stopped irrigation. Leaf area index and shoot dry weight were increased with rising of seeding rate. Lodging index was increased with the rising of seeding rate, but lodging was not showed in field. Heading date, percent ripened grain and 1,000 grain weight had no difference with seeding rate, and number of spikelets per m$^2$ were highest at the rate of 100 kg/ha. Rice yield was increased by 9% at the seeding rate of 100 kg/ha and 4% at the rate of 80 kg/ha and 120 kg/ha compared with 60 kg/ha. Therefore, it was considered that appropriate seeding rate was 100 kg/ha under water-saving culture in ridge direct seeding on dry paddy.

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Influence of Midsummer Drainage on Growth and Lodging of Rice in Direct Seeding on Dry Paddy (벼 건답직파 재배시 중간낙수가 생육 및 도복에 미치는 영향)

  • 최민규;김상수;이선용;최선영
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.5
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    • pp.574-579
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    • 1995
  • To investigate the effect of the midsummer drainage method on growth and lodging characters, Dongjinbyeo was direct seeded on dry paddy field under 4cm of soil depth at May 1 by seeding machine. Three kind of drainage methods were treated such as, once in 20day, towice in 20, 30 days and 3 times 20, 30, 40 days after flooding. As increase the drainage times, the culm and internode length were shorter, culm wall of 4th internode was thicker, breaking weight was heavier, height of center weight was lower, lodging index was reduced, and dry weight of root was increased. Field lodging occured seriously at none drainage but didn't, with two or three times of drainage. Grain yield was not shown significantly different compared with constant flooding irrespective of midsummer drainage times. Therefore two or three times of midsummer drainage could be recommended as the effective water management for the reduction of lodging occurance in direct seeding culture on dry paddy field.

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Effect of Rice-straw and Dead Waterfoxtail Mulch on Growth of Rice and Paddy Weeds in No-tillage Rice Cultivation (벼 무경운재배시 볏짚과 둑새풀 고사체 피복이 벼와 논잡초의 생육에 미치는 영향)

  • Chae, J.C.;Jun, D.K.;Kim, D.W.
    • Korean Journal of Weed Science
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    • v.18 no.3
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    • pp.191-196
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    • 1998
  • This experiment was conducted to investigate the mulch effect of rice straw and dead water foxtail treated with herbicides on weed germination, seedling establishment, and early growth of rice under the no-till culture condition. The percent seedling establishment of rice straw + dead water foxtail mulch was decreased significantly compared to rice straw mulch and non-mulch. Rice straw mulch and rice straw + dead water foxtail mulch inhibited the early growth of no-till direct seeded rice remarkably. However, they promoted rice growth after active tillering stage. Rice straw mulch and rice straw+dead water foxtail mulch in no-till direct seeding decreased weed occurrence significantly. The control value of barnyardgrass, compared with non-mulch, was 96.5% in the rice straw mulch and 75.6% in the rice straw + dead water foxtail mulch, respectively. The pH and concentration of dissolved oxygen in irrigated water were reduced significantly by both rice straw mulch and rice straw+dead water foxtail mulch during early rice growth stage.

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Influence of Midsummer Drainage Times on Lodging and Growth of Rice in Direct Drill Seeding Culture on Puddled Soil (벼 무논골뿌림 재배시 중간낙수 회수가 도복 및 생육에 미치는 영향)

  • Kim, Sang-Su;Choi, Weon-Young;Seok, Soon-Jong;Lee, Seon-Yong;Kim, Jong-Ho;Cho, Dong-Sam
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.1
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    • pp.33-38
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    • 1995
  • This experiment was conducted to elucidate the effect of the midsummer drainage times on lodging characters, field lodging and yield in direct seeding rice culture in puddled soil. Dongjinbyeo was seeded at May 11 by seeding machine with 4cm of furrow depth and drained, one(50days after seeding DAS)) two (30DAS and 50DAS), and three times (30DAS, and 50DAS and 60DAS). The results are as follows. Culm length was shorten and the wall of N3, N4 were thicken as the drain-age times were increased. As the drainage times were increased breaking weights were increased but the lodging index were decreased. Lodging was occurred seriousely at none drainage, but wasn't occurred two or three times drainage. Yield was higher at 1~2 times drainage compared with none and three times drainage. Therefore, two times midsummer drainage is recommend-able water management method for direct seeding rice culture in puddled soil.

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A Study on Transition of Rice Culture Practices During Chosun Dynasty Through Old References IX. Intergrated Discussion on Rice (주요(主要) 고농서(古農書)를 통(通)한 조선시대(朝鮮時代)의 도작기술(稻作技術) 전개(展開) 과정(過程) 연구(硏究) - IX. 도작기술(稻作技術)에 대(對)한 종합고찰(綜合考察))

  • Guh, J.O.;Lee, S.K.;Lee, E.W.;Lee, H.S.
    • Korean Journal of Weed Science
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    • v.12 no.1
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    • pp.70-79
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    • 1992
  • From the beginning of the chosun dynasty, an agriculture-first policy was imposed by being written farming books, for instance, Nongsajiksul, matched with real conditions of local agriculture, which provided the grounds of new, intensive farming technologies. This farming book was the collection of good fanning technologies that were experienced in rural farm areas at that time. According to Nongsajiksul, rice culture systems were divided into "Musarmi"(Water-Seeded rice), /"Kunsarmi"(dry-seeded rice), /transplanted rice and mountainous rice (upland rice) culture. The characteristics of these rice cultures with high technologies were based of scientific weeding methods, improved fertilization, and cultivation works using cattle power and manpower tools systematically. Reclamation of coastal swampy and barren land was possible in virtue of fire cultivation farming(火耕) and a weeding tool called "Yoonmok"(輪木). Also, there was an improved hoe to do weeding works as well as thinning and heaping-up of soil at seeding stages of rice. Direct-seeded rice culture in flat paddy fields were expanded by constructing the irrigation reservoirs and ponds, and the valley paddy fields was reclaimed by constructing "Boh(洑)". These were possible due to weed control by irrigation waters, keeping soil fertility by inorganic fertilization during irrigation, and increased productivity of rice fields by supplying good physiological conditions for rice. Also, labor-saving culture of rice was feasible by transplanting but in national-wide, rice should not basically be transplanted because of the restriction of water use. Thus, direct-seeded rice in dry soils was established, in which rice was direct-seeded and grown in dry soils by seedling stages and was grown in flooded fields when rained, as in the book "Nongsajiksul". During the middle of the dynasty(AD 1495-1725), the excellent labor-saving farmings include check-rowing transplanting because of weeding efficiency and availability in rice("Hanjongrok"), and, nurserybed techniques (early transplanting of rice) were emphasized on the basis of rice transplanting ["Nongajibsung"]. The techniques for deep plowing with cattle powers and for putting more fertilizers were to improve the productivity of labor and land, The matters advanced in "Sanlimkyungje" more than in "Nongajibsung" were, development of "drybed of rice nursery stock", like "upland rice nursery" today, transplanting, establishment of "winter barly on drained paddy field, and improvement of labor and land-productivity in rice". This resulted in the community of large-scale farming by changing the pattern of small-farming into the production system of rice management. Woo-hayoung(1741-1812) in his book "Chonilrok" tried to reform from large-scale farmings into intensive farmings, of which as eminent view was to divide the land use into transplanting (paddy) and groove-seeding methods(dry field). Especially as insisted by Seo-yugo ("Sanlimkyungjeji"), the advantages of transplanting were curtailment of weeding labors, good growth of rice because of soil fertility of both nurserybed and paddy field, and newly active growth because rice plants were pulled out and replanted. Of course, there were reestimation of transplanting, limitation of two croppings a year, restriction of "paddy-upland alternation", and a ban for large-scale farming. At that period, Lee-jiyum had written on rice farming technologies in dry upland with consider of the land, water physiology of rice, and convenience for weeding, and it was a creative cropping system to secure the farm income most safely. As a integrated considerations, the followings must be introduced to practice the improved farming methods ; namely, improvement of farming tools, putting more fertilizers, introduction of cultural technologies more rational and efficient, management of labor power, improvement of cropping system to enhance use of irrigation water and land, introduction of new crops and new varieties.

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Phytotoxicity Inducing Factors and Its Safening Methods for Benzenesulfonylurea Compound KSC-13906 (Benzenesulfonylurea계 화합물(化合物) KSC-13906의 약해발생요인(藥害發生要因) 및 경감방법(輕減方法))

  • Hwang, I.T.;Choi, J.S.;Hong, K.S.;Yoo, J.H.;Kim, J.S.;Cho, K.Y.
    • Korean Journal of Weed Science
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    • v.18 no.3
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    • pp.225-236
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    • 1998
  • KSC-13906 [Erythro N-{(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl} -2-(2-fluoro-1-hydroxy-n-propyl) benzenesulfonamide, US Patent 5,461,025] was investigated how can control phytotoxicity fluctuation and what a good method apply to new rice herbicide. The growth inhibition was observed when the rice plants was transplanted at a shallow depth(0 - 1cm) and leaching was low(0 - 1cm/ day) from the paddy soil. KSC-13906 appeared to move readily down into the paddy soil with water by 3cm depth in the soil column(${\phi}$ 10cm) filled with loamy sand soil under 3cm/day of leaching condition. Artificial control releasing pattern, designed as treated with KSC-13906 of 9 or 18g ai/ha either at a once or daily treated dividing volume of 1/20, 1/25 and 1/30 of the total volume, increased the safety of KSC-13906 to direct seeded and transplanted rice. The safety of KSC-13906 was also enhanced when KSC-13906 was mixed with dymron. For example, the mixture of KSC-13906 and dymron effectively reduced injury of direct seeded rice plants at 18 and 500g ai/ha, respectively, treated 7 days after transplanting. However, combination of KSC-13906 and several herbicides didn't show any synergistic effetct on herbicidal activity and safening effect on rice. However, the combination of KSC-13906+dymron (9~12+250~500g ai/ha) or KSC-13906+mefenacet+dymron(9+250+250g ai/ha) controlled almost all weeds in paddy field without causing any injury to rice and thus the combination would successfully be used as an oneshot herbicide in rice culture.

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Studies on Selective Herbicides to Cucurbitaceae Crop (호려과작물(葫藘科作物)에 대한 선택성제초제선발(選擇性除草劑選拔)에 관한 연구(硏究))

  • Ryang, H.S.;Moon, Y.H.;Kim, N.E.;Lee, J.H.;Choi, Y.C.;Park, H.K.
    • Korean Journal of Weed Science
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    • v.8 no.2
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    • pp.208-216
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    • 1988
  • This study was conducted to select herbicides safe for cucurbitaceae crops under the polyethylene film mulching culture. No crop injury with ethalfluralin (N-ethyl-N-(2-methylally)-2, 6-dinitro-4-(trifluoromethyl) aniline) was found in gourd, water melon, cantaloup, cucumber and pumpkin of direct seeded culture. There was no significant reduction in fresh weight of gourd and pumpkin at the rate of 1080 g a.i./ha, that of water melon, cantaloup and cucumber at the rate of 720 g a.i./ha. Napropamide (N,N-diethyl-2-(${\alpha}$-naphthyloxy) propionamide) did not cause any crop injury at the rate of 1500 to 3000 g a.i./ha. There was no significant reduction in fresh weight of gourd, pumpkin and cucumber at the rate of 3000 g a.i./ha, and that of cantaloup and water melon at the rate of 1500 g a.i./ha. Trifluralin (${\alpha}$, ${\alpha}$, ${\alpha}$-trifluoro-2,6-dinitro-N, N-diprophlaniline) did not cause any crop injury in gourd. When ethalfluralin, napropamide and nitralin were applied to the transplanted seedlings of water melon and cantaloup, no significant reduction in the fresh weight were observed. The weeding effect greater than 90% was obtained with ethalfluralin at 720 to 1080 g a.i./ha and pendimethalin (N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine) at 1268 g a.i./ha. The rest treatment gave the weeding effect ranging from 81 to 90%.

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