• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.211-220
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• 1999

The corn is mostly planted in mid-April in single-cropping silage system if possible, however, in a double-cropping silage system, the corn planting date is delayed until after the mid-May. The objective of this study was to evaluate agronomic characteristics and forage performance of the eight government recommended corn hybrids for silage at two dates of planting. Split-plot design replicated three times was used, that is, main plots were planting dates, sub-plots were eight hybrids at Suweon in 1997. Days from planting to silking of optimum planting was 84 days and that of late was 69 days. The difference in silking day among the hybrids was 6 days at optimum planting and 2 days at late planting. Plant height of optimum planting corn was higher than that of late one, however, ear height and stem diameter of optimum planting were lower than those of late planting corn. Among the corn hybrids tested, plant heights of 'P3156' and 'P3163' were higher than those of the other hybrids. Ear height of 'DK713' was the lowest among the corn hybrids and stem diameter of 'P3394' was thicker than that of the other hybrids. European corn borer(ECB) damage(16.6%) at optimum planting was lower than that(49.9%) of late, however, there were no significant ECB damage differences among the corn hybrids tested. Whole plant dry matter(DM) contents of 'P3525', 'P3394' and 'P3352' hybrids were higher than those of the other corn hybrids at harvest. Ear percentages of the total dry matter(DM) of 'P3394' and 'P3156' were higher than those of the other corn hybrids. Dry matter(DM) and total digestible nutrients(TDN) yields(19,696 and 14,621kg/ha) at optimum planting were higher than those (17,163 and 12,570kg/ha) of late planting, while there were no significant differences in DM and TDN yields among the corn hybrids tested. And those hybrids with greater proportion of grain in the whole plant have higher DM and TDN yields. Correlation coefficients for days from planting to silking with DM and TDN yields were $0.84^{**}$ and $0.87^{**}$, and those for ear percent were $0.86^{**}$ and $0.87^{**}$. Results of this study indicate that optimum planting date(15 April) is better than late planting date(16 May) in agronomic characteristics and forage production of silage corn. Days from planting to silking and ear percent as welI as other characters are important factors screening the corn hybrid for silage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.79-88
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• 2022

This study was conducted to evaluate the productivity of whole crop silage wheat utilizing the paddy fields during a couple of years from 2019 to 2021 in Suwon, Korea. This investigation was used the two maturity types of wheat cultivar 'Cheongwoo' (early) and 'Taeu' (late). The heading date of 2^nd year (Oct. 2020 to May. 2021) cultivation was delayed about 11 to 13 days by more than 1^st year (Oct. 2019 to May. 2020). The growth characteristics were shown that the plant height was increased in 2^nd cultivation, while the number of culms and the panicle part ratio were decreased. Moreover, the nutritive value of 'Cheongwoo' and 'Taeu' were also decreased in 2^nd cultivation. These changes have thought to a difference of the precipitation by cultivation years. Because, the precipitation during the period from the end of winter dormancy to the harvesting stage in 2^nd (337 mm) cultivation was more about twice than 1st (169.3 mm) cultivation. However, the dry matter yield of 'Cheongwoo' was not shown a statistical difference by cultivation years, while 'Taeu' was shown to decrease tendency. The total dry matter yield regardless of the cultivation years were higher in 'Cheongwoo' than 'Taeu', and especially 'Cheongwoo' was more 3 tons per hectare (15.3 t/ha) than 'Taeu' (12.6 t/ha) at 2^nd cultivation (p<0.01). The trend of dry weight in 'Cheongwoo', early mature type, showed a relatively high ratio of dry matter (p<0.05) was considered that due to a high panicle ratio by a fast heading and an adequate weight of panicles by a sufficient maturing. In conclusion, selecting the early maturity cultivars could achieve a higher and more stable total dry matter yield considering the cropping system in the central region. Furthermore, it also has the advantage of being able to double-cropping system with forage rice, which has considered the maximum whole-crop forage production year-round. These results suggest that the 'Cheongwoo' be optimum cultivar to produce the year-round forage on paddy fields in the central region.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.1
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• pp.54-60
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• 2022

The planting date of corn for silage has been delayed because of spring drought and double cropping system in Korea. This experiment was conducted to evaluate agronomic characteristics, forage production and feed value of corn at April and May in 2019. Experimental design was a split-plot with three replications. Planting dates (12 April and 10 May) were designated to the main plot, and corn hybrids ('P0928', 'P1543' and 'P2088') to the subplot. The silking days of the early planting date (12 April) was 79 days and that of the late planting date (10 May) was 66 days (p<0.0001), however, there were no significant differences among the corn hybrids. Ear height of the late planting date was higher than that of the early planting (p<0.05), while there were no significant differences in plant height of corn. Insect resistance at the early planting was lower than that of late planting (p<0.05), however, lodging resistance was no significant difference at planting date. The rice black streaked virus (RBSDV) infection of early planting was 3.7% and that of late planting was 0.3% (p<0.001). Dry matter (DM) contents of stover, ear and whole plant had significant difference at planting date (p<0.05). And differences in ear percentages were observed among the corn hybrids (p<0.01). And ear percentages of early maturing corn ('P0928') was higher than for other hybrids. Ear percentage at the early planting date was higher than that at the late planting date (p<0.01). DM and total digestible nutrients (TDN) yields had significant difference at planting date, however, there were no significant differences among the corn hybrids. DM and TDN yields at the late planting (21,678 kg/ha and 14,878 kg/ha) were higher than those of the early planting (13,732 kg/ha and 9,830 kg/ha). Crude protein content at the early planting date was higher than that of the late planting. Acid detergent fiber content of the late planting was lower than that of the early planting date (p<0.01), while there were no significant neutral detergent fiber content difference among the corn tested. Calculated net energy for lactation (NE_L) and TDN at the early planting were higher than those of at the late planting (p<0.01). Results of this our study indicate that the late planting date (May) is better than early planting date (April) in forage yield and feed value of corn. Therefore, the delay of planting date by May was more suitable for use in cropping system.

• Korean journal of applied entomology
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• v.31 no.3
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• pp.205-240
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• 1992

In reality, it is a green revolution of the entire agricultural matrix in Korea that integrated pest control plays an important role in the possible breakthrough in rice self-sufficiency. In paddy agroecosystem as man-modified environment, rice is newly established every year by transplantation under diverse water regimes which affect a microclimate. Standing water benefits rice by regulating the microclimate, but it favors the multiplication of certain pets through the amelioration of the microclimate. Further, the introduction of high yielding varieties with the changing of cultural practices results in changing occurrence pattern of certain pests. In general, japonica type varieties lack genes resistant to most of the important pests and insect-borne virus diseases, whereas indica type possesses more genes conferring varietal resistance. Thus, this differences among indica type, form the background of different approaches to pest management. The changes in rice cultivation such as double cropping, growing high-yielding varieties requiring heavy fertilization, earlier transplanting, intensvie-spacing transplanting, and intensive pesticide use as a consequence of the adoption of improves rice production technology, have intensified the pest problems rather than reduced them. The cultivation of resistant varieties are highly effective to the pest, their long term stability is threathened because of the development of new biotypes which can detroy these varieties. So far, three biotypes of N. lugens are reported in Korea. Since each resistant variety is expected to maintain several years the sequential release of another new variety with a different gene at intervals is practised as a gene rotation program. Another approach, breeding multilines that have more than two genes for resistance in a variety are successfully demonstrated. The average annual rice losses during the last 15 years of 1977-’91 are 9.3% due to insect pests without chemical control undertaken, wehreas there is a average 2.4% despite farmers’insecticide application at the same period. In other words, the average annual losses are prvented by 6.9% when chemical control is properly employed. However, the continuous use of a same group of insecticides is followed by the development of pest resistance. Resistant development of C. suppressalis, L. striatellus and N. cincticeps is observed to organophosphorous insecticides by the mid-1960s, and to carbamates by the early 1970s in various parts of the country. Thus, it is apparent that a scheduled chemical control for rice production systems becomes uneconomical and that a reduction in energy input without impairing the rice yield, is necessarily improved through the implementation of integrated pest management systems. Nationwide pest forecasting system conducted by the government organization is a unique network of investigation for purpose of making pest control timely in terms of economic thresholds. A wise plant protection is expected to establish pest management systems in appropriate integration of resistant varieties, biological agents, cultural practices and other measures in harmony with minimizing use of chemical applications as a last weapon relying on economic thresholds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.325-330
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• 2004

This study was carried out to determine adequate planting date, to compare the growth characteristics between early and late maturing cultivars, and to provide the data for the cultivation techniques of soybean [Glycine max (L.) Merr.] in double cropping system with winter crops on paddy field in Korea. Cultivars were planted on 26 May, 16 June, and 7 July with a planting density of $70cm(row\;widtb)\;{\times}\;10cm$ (planting spacing). Seed yield of soybean planted on June 16 and July 7 was approximately $37\%\;and\;53\%$, respectively, less than that of conventional planting date of May 26 in Pungsan-namulkong, and planted on June 16 and July 7 was about $30\%\;and\;37\%$, respectively, less then that of conventional planting date of May 26 in Hanamkong. The number of pods and seeds per plant decreased as planting date delayed. Seed weight increased in Pungsan-namulkong but decreased in Hannamkong as planting date delayed. The flowering date was late in delayed planting plots, but it was shorted for days from emergence to flowering and from emergence to maturity. The plant height of Hannamkong was greater than Pungsan-namulkong from the emergence to flowering stages, but in contrast, it was greater in Pungsan-namulkong than Hannamkong after flowering stage (50d after emergence) when it planted on May 26. There were no significant differences between two soybean cultivars at planting dates of June 16 and July 7. Leaf number, leaf area, and dry matter were also reduced by late planting, and Both of them were shown in high reduction at the later planting. There was a high significant difference at the flowering $(r\;=\;0.87^{**})$ and pod formation $(r\;=\;0.91^{**})$ stages between leaf dry matter and seed yield. Crop growth rate (CGR) was greater at $R2\~R3$ growth stages compared to $R3\~R4\;or\;R4\~R5$ growth stages in two soybean cultivars and the greatest CGR was obtained at planting date of May 26 in two soybean cultivars except for R4-R5 growth stage in Pungsan-namulkong. There was a highly significant positive difference between the seed yield and the leaf area index (LAI) across R3 to R4 and R2 to R3 stages. The photosynthetic rate $(P_N)$ of the uppermost leaf position had no significant difference among planting dates and between two soybean cultivars. However, $P_N$ of the $7^{th}$ leaf position increased as the planting date delayed.

• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.381-391
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• 2009

Crop production can be secured by the cycle of green manure crops as an alternative of the chemical fertilizer. Recently, rapeseed (Brassica napus L.) has been cultivated in the south part of Korea for the production of biodiesel. In this research, we focused on recycling rapeseed residue, which is produced after harvesting the rapeseed for biodiesel, as a potential source of nitrogen to the succeeding crop. Pot experiment was conducted to evaluate the effects of winter rapeseed as green manure on mineralization and uptake of nitrogen to the succeeding corn (Zea mays L.). Result showed that total nitrogen and C/N ratio of rapeseed at the harvesting stage was 0.54% and 63, respectively. The incorporation of rapeseed without decomposition period slightly inhibited nitrogen uptake to the succeeding corn compared to those with 30 days decomposition period. The pH and EC values of soils increased by increasing the period of decomposition of rapeseed from 5.2 to 6.4 and from 0.05 dS/m to 0.21 dS/m, respectively. Significant amounts of $NH_4^+$ and $NO_3^-$ are released by incorporation of rapeseed. The succeeding corn took up 86% and 88% of inorganic nitrogen released from the rapeseed with and without decomposition period, respectively. The overall results suggested that the utilization of rapeseed residue as green manure can be an alternative source of nitrogen in corn-rapeseed double cropping system.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.1
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• pp.9-14
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• 2011

This experiment was carried out to breed a very early maturing variety of Italian ryegrass (Lolium multiflorum Lam.) in Grassland and Forage Crops Division, National Institute of Animal Science, RDA, Cheonan from 2009 to 2010. A new variety, 'Green farm' is a diploid variety with green in leaf color and has erect and semi-erect growth habit in late autumn and early spring, respectively. 'Green farm' was on 28 April in heading date as a early-maturing variety. 'Green farm' was also wider by 0.4 mm in flag leaf width, longer by 0.8 cm in flag leaf length and shorter by 5 cm in plant height than those of control variety, 'Florida 80', respectively. 'Green farm' was thicker in stem thickness and stronger in winter hardness than those of the 'Florida 80'. Dry matter (DM) yield (11,790 kg/ha) of 'Green farm' was similar to that of 'Florida 80'. In vitro dry matter digestibility (IVDMD), total digestible nutrient (TDN) and crude protein (CP) of 'Green farm' were 68.7, 63.3 and 10.3% which are 1.9, 1.7 and 0.6% higher than those of 'Florida 80', respectively. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) of 'Green farm' were 32.5 and 54.6% which are 2.2 and 4.3% lower than those of the 'Florida 80', respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.243-250
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• 2011

This experiment was conducted to evaluate agronomic characteristics, forage quality and dry matter (DM) yield of early-maturing hairy vetch 'Cold green', 'Haymaker plus', 'Cappello' and medium-late maturing cultivar 'Cheong pa', 'Challenger', 'Hungvillosa' and 'Latigo' at Seongju in the Kyeongbuk from 2009 to 2011. The experiment was arranged in randomized complete block design with three replications. Hairy vetchs were seeded on Sep. 26 and Oct. 11 in 2009 and 2010. Vetch plants were harvested on 30 Apr. in 2010 and 2011. Cold tolerance for Haymaker plus and Cappello were a little lower than other cultivars. Fifty percent-flowering dates of Cold green had earlier than others and Haymaker plus and Cappello were earlier than Cheong pa, Challenger, Hungvillosa and Latigo. Cheong pa and Challenger were ealirer than Hungvillosa and Latigo. The DM yield of Cold green was the highest (p<0.05) of the cultivar except Haymaker plus. Haymaker plus was higher (p<0.05) than others and Cappello, Cheong pa, Challenger were higher (p<0.05) than Hungvillosa and Latigo in 2010. In 2011, the DM yield of Cold green was the highest (p<0.05) of the cultivar and Haymaker plus was higher (p<0.05) than others. Cappello was higher (p<0.05) than Hungvillosa and Latigo. Cheong pa and Challenger were higher (p<0.05) than Latigo. Vetch cultivar was high in crude protein (CP) and low in Acid detergent fiber (ADF). According to the results obtained from this study, it is suggested that early-maturing cultivar would be recommendable for fall sown vetch for DM production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.9-15
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• 1986

To establish an efficient light control method using three covering materials on tunnel shaped rice seed-bed at greening stage after seedling emergence, four rice cultivars, Nampungbyeo, Taebaegbyeo, Seonambyeo, and Seomjinbyeo were sown on 15 April and 10 May in 1983 and 1984 respectively. After seedling emergence by a simplified emerging methods the seedling boxes were moved onto tunnel shaped seed-bed which was covered with combined matrials of PE film, silverpoly sheet, and spunbonded polyester fabric. For machine transplanting of rice seedlings in cases of early season and optimum season seeding in central part of Korea, PE film tunnel with silverpoly mulched, and PE film tunnel methods with spunbonded polyester fabric mulched reduced injuries of non-parasitic seedling damping-off and a albinism as affected by it, protected rice seedlings from injuries by extremely low temperature in the night, and reduced less differences in diurnal temperature than those in the other covering methods. At late season seeding for double cropping system of paddy field in southern part of Korea, a single silver-poly or a single spunbonded polyester fabric-covered tunnel method showed good green seedlings, and prevent-ed extreme rising of diurnal temperature by light interception in the tunnel.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.80-80
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• 2022

본 연구에서는 남부지역 논의 이모작 작부체계로부터 생산한 국산밀의 품질 특성을 살펴보았다. 벼 및 이의 대체작물(검정콩, 참깨, 들깨)과 연계한 작부체계별로 생산된 국산밀의 제분율은 모든 토양에서 70% 이상으로 높았으며, 밀가루의 색상은 전작 작물의 종류에 따라 색도(L^*, a^*, b^*) 값과 백색도 지수가 변화하였다. 특히, 흰색의 정도를 나타내는 L^*값과 백색도는 벼 전작 토양에서 수확한 밀에서 높았다. 그러나 다량 및 미량 영양소 함량은 벼 전작물 토양에서 수확된 밀에서 낮았고 대체 작물을 전작한 토양에서 생산한 밀에서 대체로 높았다. 다량 영양소 중 P와 Mg의 함량과 미량 영양소 중 Zn와 Cu의 함량은 검정콩을 전작한 토양에서 수확한 밀에서 특히 높았다. 국산밀의 회분, 단백질, 아밀로스와 손상전분 함량은 각각 0.45-0.59%, 7.7-9.5%, 22.3-24.0%와 5.0-5.9%이다. 국산밀 중에 조경밀은 단백질 함량이 다른 품종에 비해 높고 질이 우수하여 제빵용으로 이용되고 있는데, 본 연구에서는 작부체계에 관계없이 전체적으로 10% 이하로 낮은 특성을 보였다. 그나마 검정콩을 전작한 토양에서 수확한 밀에서 9.45%이며, 벼를 전작한 토양에서는 8.0% 이하로 극히 낮았다. 또한 SDS-침전가도 검정콩 전작 토양에서 수확한 밀에서 높았으며, 회분 함량은 0.6% 이하로 1등급에 해당되었다. 논토양에서 참깨나 콩, 들깨 등의 벼 대체 작물들의 전작은 토양의 물리화학적 특성을 개선하고 제빵공정에 좀 더 유리한 고품질의 밀을 생산하는 데 이바지할 수 있음을 보여준다. 그러나 검정콩-밀 작부체계의 생육일수(344일)가 벼-밀(331일), 들깨-밀(337일), 참깨-밀(310일) 보다 길어 앞뒤 작물의 작기 연결성에 있어서 여유가 없었으며, 기상환경의 변화에 따라 검정콩의 수확시기가 늦어지게 되면 밀 파종 시기와 겹칠 수 있는 우려가 있다. 차후에 시비 기준을 달리한 조건에서 밀의 생산성 증대와 더불어 최고 품질의 밀을 생산할 수 있는 체계를 확립하고자 한다.