• Title/Summary/Keyword: Seeding date

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Improvement of Seedling Stand and Lodging Prevention in Direct Seeded Rice (벼 직파재배(直播栽培) 입묘율향상(立苗率向上)과 도복경감(倒伏輕減))

  • Oh, Yun-Jin;Kim, Chung-Kon
    • 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.

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Dry Matter Weight and Physicochemical Property of Job’s Tears Grain of Different Sowing Dates and Days after Flowering (율무 파종기 및 개화후 일수에 따른 종실중과 종실의 이화학적 특성 변이)

  • 최창균;윤기호;김광호
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.2
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    • pp.236-244
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    • 1995
  • This study was carried out to clarify the changes in dry matter weight and physicochemical property of job's tears grain during ripening period. Four varieties of job's tears were seeded at April 20, May 10, and May 30, andgrains were harvested at every 7 days from heading to maturity, The whole seed weight of thick hull varieties, Kimje and Aewon, was higher than that of improved thin hull varieties, Suwon 3 and Suwon 6, from heading to maturity, However, the dehulled grain weight of thin hull variety were higher than that of thick hullvariety from 35 days after heading. The first heading spikelet showed lower 100-grain weight com-pared with the spikelets headed at full blooming stage among the same plant. The increased rate of de hulled grain weight during maturing period was higher in thin hull variety than thick hull one, later seeding date than early seeding, and intermediate headed spikelet than early head-ed one, respectively. As maturing proceeds the protein content of de hulled grain was decreased, alkali digestibility value(ADV) showed a rising trend, and little change was found in gel consistency of milled grain flour. And same trends were found in protein content, ADV and gel consistency as the seeding date was delayed. Among amylogram properties of job's tears flour the maximum, minimum, and final viscosity as well as breakdown were decreased, and set back was increased in later seeding plots

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Yield and Nutritive Value of Spring-seeded Early and Late Maturity Italian Ryegrass (Lolium multiflorum Lam.) (이탈리안 라이그라스 춘파재배에서 조·만성 품종간 생산성 비교)

  • Kim, Ki-Yong;Ji, Hee-Chung;Lee, Sang-Hoon;Lee, Ki-Won;Kim, Won-Ho;Jung, Min-Woong;Seo, Sung;Choi, Gi-Jun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.30 no.2
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    • pp.97-102
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    • 2010
  • This experiment was carried out to know the possibility for cultivation of Italian ryegrass (Lolium multiflorum Lam.) by spring seeding in Grassland and Forages Division, National Institute of Animal Science, RDA, Cheonan from 2007 to 2008. In spring seeding cultivation, heading date of early maturity variety, 'Kospeed', was on 14 May, but late maturity variety, 'Hwasan 101', was not heading up to harvesting date. Dry matter yield of 'Kospeed' (6,819 kg/ha) was higher than that of 'Hwasan 101' (4,409 kg/ha) by 55%. Crude protein (CP) and total digestible nutrients(TDN) of 'Kospeed' were 15.6% and 62.1%, respectively and that of 'Hwasan 101' were 20.3%, and 67.5%. In these result, when cultivation of Italian ryegrass by spring seeding, selection of early maturity variety have a decided advantage for high productivity.

Optimum Sowing Date for Seed Production in Hemp (대마의 채종재배를 위한 파종적기)

  • 박규철;박태동;박인진;권병선;김상철;정병준;김명석
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.4
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    • pp.424-428
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    • 1997
  • This study was carried out to investigate the effects of sowing dates, Apr. 25, May 15, June 5 and June 25, on sex ratio, growth and seed yield of "Chonnam species", local variety of hemp plant. The results were following as. : In sex ratio according to the different seeding dates, the revealating rate of female and male plants were highest on June 25, and Apr. 25, respectively. The length of stem, the number of branches, nodes, and seed yield were increased on May 15, but these charateristics were rapidly reduced on June 25 because of short growing period. Yield of seeds was increased by 24% on May 15 comparing with 1.30ton /ha on Apr. 25.

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