• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.25-30
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• 2009

This experiment was conducted to evaluate the effect of direct seeding time on the yield and quality of whole crop rice at experimental field of Grassland and Forages Research Center, National Institute of Animal Science, RDA from 2005 to 2006. Whole crop rice variety, "Namil", was direct seeded at five different calender date (25 April, 10 May, 25 May, 4 June and transplanted at 25 May). The heading date was delayed at late seeding date. Crude protein (CP) was increased with delayed direct seeding date. The content of ADF (acid detergent fiber) and NDF(neutral detergent fiber) increased with delayed seeding date. The average TDN (total digestible nutrient) content was 61.5% and it also decreased with delayed direct seeding date. The highest DM (dry matter) yield was seeded at 25 April and transplanted at 25 May, 15,185 and 15,815 kg/ha, respectively. Although delayed direct seeding date decrease the DM yield, mid-May will be recommendable as proper direct seeding date.

• Korean Journal of Agricultural Science
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• v.9 no.1
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• pp.231-238
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• 1982

The study was done to determine the proper transplanting dates and seedling ages of rice when mechanical transplanting was attempted. Heading dates of the Milyang #23, developed from Tong-il rice was delayed by delayed transplanting and the percent of filling grain was also low. The proper heading dates for the variety should be the first part of August and the transplanting should be done by the end of May. The presumed last days for the transplantation was considered early part of June. 30 to 40 days old seedlings were very effective to have healthy rooting systems. However, the Milyang #15 had shown more tolerance to the late transplantation than Milyang #23 and the degree of delaying heading dates due to the delayed transplantation was rather smaller than that of the Milyang #23. Even when the Milyang #15 was transplanted on June 30, the heading dates were around the middle of August and the ripening percentage was comparatively high and yield was also high. Therefore, the proper heading dates of the Milyang #15 might be around the middle of August and transplanting dates should be the first part of June. The possible last dates of transplantation of the Milyang #15 was assumed to be the last days of June and the proper seedling ages would be 20 to 30 day after sowing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.386-393
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• 1984

This study was carried out to identify the ecological characters easily changeable with the conditions of temperature and day-length and to ascertain the managable means which can optimize the barley plants to secure the maximae yield and early heading under controlled condition. Yield and yield components were greatly varied with temperature. Especially, effective tiller formation and grain filling of sub-tillers were more favorably affected by thermal treatment than those of main tiller. In thermic response, 'Kangbori' was less susceptible than others, while 'Sacheon #6' showed particular susceptability. The varietal differences of photoperiodic response were recognized on all investigated traits and their degree of response were similar to those with temperature. Among varieties, 'Kangbori' was comparably sensitive on several characters while 'Sacheon #6' displaying low light-sensitivity. The turning point at which heading might be radically stimulated was estimated as about 10.5 hour day-length in 3 tested varieties and above 18 hours of irradiance was considered ineffective for more rapid heading. The condition under which barley varieties may obtain maximal yield and resonably early heading was 15$^{\circ}C$ in temperature and 12 to 15 hours of day-length, regardless of varieties. of day-length, regardless of varieties.

• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.386-391
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• 1997

A study was carried out to investigate the variation of heading date and related yield components at Honam Agricultural Experiment Station in Korea. The treatments were consisted of five transplanting time: from May 5 to July 5 at 15-day intervals, and six cultivars: two early-maturing, two mid-maturing and two late-maturing cultivars. The results showed that variation of heading at different transplanting time was not significant at transplanting after June 5 in early-maturing cultivars, and days of heading from seeding for all tested cultivars were shorter in later transplanting times. The yield components such as numher of spikelcts, percentage of ripened grain and 1.000 grain weight were found to he great on May 5 in early-maturing cultivars and on June 5 in mid-and late-maturing cultivars. Yield was maximized at transplanting of May 20 in early maturing and on June 5 in mid-and late-maturing cultivars. When transplanting time was late, the yield difference hetween early maturing cultivars and late nldtunng ones showed 44 to 77kg/10a in the transplanting of June 20, and 26~30kg/10a in the transplanting of July 5 indicating that the late-maturing cultivars take more advantage than early-maturing ones.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.2
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• pp.23-30
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• 1980

Experiments were conducted to know N, P, and K top dressing effects on yield and other agronomic characters of rice plants grown in 5-year differently fertilized soils. Four levels of nitrogen, 0, 1.2, 2.4, and 3.6kg/10a, were applied 32 days before heading in 5-year non-fertilized and PK applied plots. Four levels of P_2 $O_{5}$ and K_2 O of 0, 4, 8 and 12kg/l0a were applied 40 days before heading in 5-year NK and NP applied plots, respectively. 1. Heading was delayed by seven days in 5-year non-fertilized and PK applied plots compared to NK, NP, or NPK applied plots where nitrogen was applied as basal. However, in 5-year non-fertilized and PK applied plots heading was delayed from 1 to 4 days as amounts of nitrogen top dressing increased. Phosphorus and potassium did not affect heading date of rice plants. 2. In 5-year non-fertilized plot grain yield increased as amounts of nitrogen top dressing increased up to 2.4kg/l0a due to both increased number of panicles per hill and spikelets per panicle. However, in 5-year PK applied plot amounts of nitrogen top dressing did not affect grain yield; the number of panicle per hill increased, but the percentage of ripened grains and grain weight tended to decrease as nitrogen levels increase. 3. The number of panicle/maximum tillers ratio in percentage increased markedly as amounts of nitrogen top dressing increased in 5-year non-fertilized and PK applied plots with maximum value of 130% on the basis of maximum tillers at vegetative stage. 4. Top dressing of phosphorus and potassium did not affect yield and other agronomic characters in NK and NP applied plots.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.31-38
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• 1980

This experiment was carried out to study the heterosis and the GCA and SCA effects for days to heading of F 1 populations produced from eight wheat cultivar diallel. Greater heterosis for early heading was exhibited under the high temperature condition than under the low temperature conditions, and same results were also observed under short day condition rather than long day conditions. There are highly significant mean for GCA and SCA at all environmental conditions. Yecora F70 was showed the greatest effect, and Bezostaya and Blueboy were exhibited less effects of CCA for early heading. Significant GCA effect was expressed at high temperature and short day condition, indicating that this condition provides a better opportunity to select the materials for earliness. Selections of combination with greater effect of SCA for early heading such as Suweon 169 \times Yecora F70 were discussed for practical utilization.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.4
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• pp.268-274
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• 1990

In order to understand the effect of irrigation constraint on the growth and yield of the rice plant. two rice cultivars. Samnambyeo and Chucheongbyeo. were cultured in the pot controlled with different water levels: + 2 cm-submergence, and -17cm, -37cm, -57cm, -77cm, -97cm, -120cm, and -145cm depth from soil surface. 1. Among differently irrigated conditions, submerged condition was the best in growth and yield of both Samnambyeo and Chucheongbyeo. Yield and growth of rice decreased linearly with lowering the water level in sequence. 2. Samnambyeo appeared to be more drought resistant cultivar than Chucheongbyeo. It was regarded that physiologically critical water level on rice yield was about 70cm depth in Samnambyeo and 50cm depth in Chucheongbyeo. 3. The earliest heading date of the rice plant was from submergence condition and the head ing date was linearly delayed with lowering water level in sequence. The heading date of Samnambyeo was about 10days earlier than that of Chucheongbyeo at the same water level.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.154-159
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• 1991

A field experiment was conducted to know the feasibility of direct-seeded rice. Dry seeds of a Japonica type rice variety, Donghaebyeo, was sown from May 10 to June 20 at the 10-day intervals. The number of days from seeding to emergence decreased as planting date delayed; 13, 12, 10, 9, and 7 days at May 10, May 20. May 30. and June 10 seedings, respectively. The number of maximum tillers per ㎡ was about 700-800 at all the seeding dates and effective tiller ratio ranged 40-45%. The number of days from seeding to heading decreased as seeding date delayed; from 97 days at May 10 planting to 71 days at June 20 planting. The cumulative effective temperature (mean air temperature-15$^{\circ}C$) from seeding to heading was fairly constant having 870$^{\circ}C$ with 2.3% C.V. The number of panicles per unit area at June 10 planting was higher than that of other planting dates. Panicle length and the number of spikelets per panicle tended to decrease as seeding date delayed. The number of spikelets per unit area, 1000-grain weight, and grain yield were similar among the seeding dates except June 20 seeding. At the June 20 seeding the number of spikelets and grain yield were much lower, but 1000-grain weight was higher compared with other seeding dates. Grain fertility and percent ripened grains was similar among all seeding dates.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.3
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• pp.15-20
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• 1980

Heritability of heading date, maturing date and culm length were high and the year variation was relatively low. Yield components were considerably low in heritability due to large year variation. Direct effects of number of spikes/$m^2$ and 1, 000 grain weight to yield were high. For improved selection efficiency, at least three years continuous evaluation of experiments would be desired.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.321-328
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• 2009

This experiment was carried out to investigate the effect of cultivar and seeding date on the winter survival rate, quality and DM yield of Italian ryegrass on paddy field for three years in Suwon. Seeding started from 30th Sep. 2003. at intervals of five days and finished 20th Oct. New varieties of Italian ryegrass used in this experiment were "Kospeed", "Kowinmaster" and "Hwasan 101". The winter survival average rate of 5th Oct. seeding plot was 89.8% and it decreased with delayed seeding date. The heading date of "Kospeed" was 7th~13rd May, "Kowinmaster" was 16th May, but "Hwasan 101 ho" didn't show heading until 17th May. Dry matter (DM) yields of 30th Sep. seeding plot were Kospeed 7,909kg/ha, Kowinmaster 6,398 kg/ha and Hwasan 101 ho 5,204 kg/ha. DM yield was decreased with delayed seeding date. Total digestible nutrient (TDN) yield was also decreased with delayed seeding date. Crude protein (CP) content was the highest in Kospeed. seeding plot as 18.3% and in vitro dry matter digestibility (IVDMD) was not showed significant difference among seeding dates.