• Title/Summary/Keyword: Sowing rates

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Effect of Sink and Source Related Characteristics on Grain Weight and Grain Nitrogen Content in Rice (Sink와 Source 관련형질 변이가 벼 종실중 및 종실질소함량 변이에 미치는 영향)

  • Lee, Chung-Kuen;Kwon, Young-Up;Lee, Jae-Eun;Seo, Jong-Ho;Shin, Jin-Chul;Lee, Byun-Woo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.1
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    • pp.45-54
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    • 2009
  • This experiment was conducted to clarify the effects of source and sink related characteristics on grain weight increase and grain nitrogen accumulation in rice. Source was modified by leaf removing treatment with no sink modification in 2002 and sink and source were modified at the same time by different sowing dates, N fertilization rates, row spacings, and thinning treatments at heading in 2007. Grain weight (GW) and grain assimilates produced by photosynthesis during grain-filling ($GW_P$) increased with the increase of source, while the grain assimilates retranslocated from leaf and stem ($GW_T$) decreased. Among the source-related characters, shoot dry weight were most closely related with GW. GW was dependant on $GW_P$ rather than on $GW_T$. Grain nitrogen content (GN) and grain nitrogen absorbed from soil during grain-filling ($GN_S$) increased with the increase of source, while the grain nitrogen retranslocated from leaf and stem ($GN_T$) decreased. Shoot nitrogen content among the source-related characters was related most closely with GN. The contribution of $GN_T$ to GN was relatively large although GN depended more largely on $GN_S$ than $GN_T$. In addition, GN was supplied firstly from $GN_S$ or from $GN_S$ and $GN_T$ at the same time.

Effects of Specific Gravity on Germination and Emergence of Foxtail Millet (Setaria italica Beauvois) (염수선 종자 정선법에 따른 조의 발아 및 출현율)

  • Jung, Ki-Youl;Choi, Young-Dae;Chun, Hyen-Chung;Lee, Sang-Hun;Jeon, Seung-Ho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.64 no.2
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    • pp.144-151
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    • 2019
  • The establishment rate of foxtail millet seeds is greatly affected by soil environment conditions. To enhance germination viability and stable production of foxtail millet seeds, it is important to select seeds with a high density. Therefore, this study tested the selection of high-quality seeds using salt solution (specific gravity: 1.000, 1.005, 1.010, 1.015, 1.020, 1.025, 1.030, 1.035, and $1.040g\;L^{-1}$) and investigated their germination rates, percentages of emergence, and seeding quality. In this study, three varieties were tested: 'Hwanggeum', 'Samdachal', and 'Kyeongkwan1'. The thousand seed weight of all three varieties increased proportionally with specific gravity. The highest thousand seed weight was observed at the selection with $1.040g\;L^{-1}$ specific gravity, which also had the highest germination rate of 88.3%, 86.7%, and 90.6%, for 'Hwanggeum'; 'Samdachal'; and 'Kyeongkwan1', respectively. The results of seeding quality indicated that higher the specific gravity during selection, the higher were the values of plant growth (plant height, leaf length, stem diameter, root length, root weight, and stem weight). All the three varieties were found to be longer or heavier for seeds selected at the specific gravity of $1.040g\;L^{-1}$. The packing germination viability investigation found that higher the specific gravity for selection of seeds, the higher was the percentage of emergence (PE) and the emergence rate index (ERI). The PE was the highest for seeds selected at $1.040g\;L^{-1}$ specific gravity (85.3, 83.0, and 87.0%), and ERI was also as high as $2.82d^{-1}\;m^{-1}$ or more at $1.040g\;L^{-1}$. Selection of seeds with salt solution resulted in high germination viability of foxtail millet. Therefore, sowing seeds selected at $1.040g\;L^{-1}$ specific gravity is expected to help substantially in increased productivity.

Seed Productivity of Spring Sown Italian Ryegrass(Lolium multiflorum Lam.) Depending on Seeding Rate in Gangwon Province (강원 산간 지역에서 봄철 파종량에 따른 이탈리안 라이그라스(Lolium multiflorum Lam.)의 종자 생산성)

  • Jeong, Eun Chan;Kim, Hak Jin;Li, Yan Fen;Kim, Meing Joong;Ji, Hee Chung;Kim, Jong Geun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.41 no.1
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    • pp.23-28
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    • 2021
  • This experiment was conducted to compare the seed productivity of Spring sown Italian ryegrass(Lolium multiflorum Lam.) depending on the seeding rates(20kg/ha, 30kg/ha, 40kg/ha) in Gangwon region. The experiment was a randomized block design with three replications. The test plots were located in alpine areas of about 600 m above sea level in Gangwon province. The tested Italian ryegrass variety was 'Greencall' developed by the National Institute of Animal Science, RDA. Italian Ryegrass was sown on March 26, 2020, and the seed harvesting was on the 60th day(2 July) from heading date. The heading date was May 8 with no difference, There were no significant differences in the agronomic characteristics including plant height. 30kg/ha seed rate was the highest at 146.8 seed/spike and 40kg/ha seed rate was the lowest at 114.7 seed/spike for the number of seeds per spike. The number of spikes per unit area was the highest in 40kg/ha at 886/㎡ and the lowest in 20kg/ha at 750/㎡. The yield of seed and straw was the highest in 40kg/ha at 1,288kg/ha and 2,970kg/ha respectively, but there was no difference. From the above results, the production of Italian ryegrass seeds through spring sowing in the Gangwon region is not much than autumn seeding, requiring the input of various technologies to increase productivity in the future, and it is desirable to determine the production cost through economic analysis was evaluated.