• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.63-68
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• 1975

Several high protein mutant lines(M4 plant generation, 1974) obtained from X-ray irradiated Jinheung variety were examined at three different locations for their agronomic characters, protein and grain yields. On the other hand, high protein-short culmed-early maturity mutant line No. 398 (M$_{10}$ plant generation, 1974) induced from Hokwang was crossed back to its mother to investigate the gene(s) controlling protein and its pleiotropic relation to other mutated characters. Although variation of protein percent of mutant lines from Jinheung was comparatively large depending on year and location, most of the high protein mutant lines had higher protein yield per unit area than the mother variety and their grain yields were equal to or better than the mother, being resistant to both leaf and neck blast. They were several days earlier-maturing and had shorter-culm except one mutant line. The culm length and heading date of F$_1$ between high protein mutant 398 and its mother Hokwang were intermediate. Accurate assessment of segregation of culm length and heading date in F$_2$ generation and protein percent in F$_3$ seeds will be conducted in 1975.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.4
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• pp.333-339
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• 2015

A thermal time-based phenology model of Kimchi cabbage was developed by using the field observed growth and temperature data for the purpose of accurately predicting heading and harvest dates among diverse cropping systems. In this model the lifecycle of Kimchi cabbage was separated into the growth stage and the heading stage, while the growth amount of each stage was calculated by optimal mathematical functions describing the response curves for different temperature regimes. The parameter for individual functions were derived from the 2012-2014 crop status report collected from seven farms with different cropping systems located in major Kimchi cabbage production area of South Korea (i.e., alpine Gangwon Province for the summer cultivation and coastal plains in Jeonnam Province for the autumn cultivation). For the model validation, we used an independent data set consisting of local temperature data restored by a geospatial correction scheme and observed harvest dates from 17 farms. The results showed that the root mean square error averaged across the location and time period (2012-2014) was 5.3 days for the harvest date. This model is expected to enhance the utilization of the Korea Meteorological Administration's daily temperature data in issuing agrometeorological forecasts for developmental stages of Kimchi cabbage grown widely in South Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.3
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• pp.318-325
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• 1986

The studies were performed to obtain the basic informations on the influence of weather condition for grain yield and yield components in barley. The data of Olbori tested in 9 sites for 12 years were used in the studies. Milled grain yield was decreased in paddy field after rice harvested comparing to the upland condition, and yield potential was differed by test sites with the most stable yield in Gyeongnam. The coefficients of variation analyzed for milled grain yield by years were 12.2-42.6% with the differences between high-yield and low-yield year. Heading date was earlier in high-yield year and southern part compared to the low-yield year and middle part of the Korean peninsular showing the negative correlation between grain yield and heading date. High-yield year showed longer in culm length, shorter in spike length, almost same in number of grains per spike, and lower in 1,000grain weight compared to the low-yield year. Correlation analyzed between number of spikes and grain yield showed positive relationship. Temperatures affected to the grain yield analyzed by high in vegitative growth stage, low in alternative growth stage, and almost same in reproductive growth stage in high-yield year comparing to the low-yield year, however no remarkable differences of temperatures affected were detected in over wintering stage between high-yield and low-yield year. Precipitation amount in high-yield year was lesser in sowing time, more in seedling time, and lesser in over wintering time than those of the low-yield year. Correlation between rainfall amount in the early of April and grain yield showed significant negative correlation with the remarkable affects to the grain yield. Sunshine hours in high-yield year were longer in sowing time, shorter in over wintering time, and after the over wintering time to harvesting time was longer than those of the low-yie-ld year.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.123-129
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• 1982

To determine the optimum harvesting date with good grain yield and quality, six different harvesting dates were tested from 25 to 50 days heading with five days intervals, using two varieties of Baekdong, naked barley and Olmil, wheat. The dates when grain yield, 1,000 grain weight and grain/whole spike weight ratio were reached to the highest were 35 and 40 days after heading for Baekdong and Olmil, respectively. Various grain qualities such as unhulled grain, plumpness, protein content and whiteness of grain were also very good at that times. One day earlier harvesting before the optimum dates resulted in yield decreases by 3.9% for Baekdong and 4.4% for Olmil. And it might be delayed for each 5 days with Combine harvesting.

• Korean Journal of Weed Science
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• v.10 no.4
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• pp.248-254
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• 1990

Initial crop injury, plant growth and yield of machine-transplanted rice of seedlings different in plant age (8-, 20-, and 35-day-old seedlings) after application of herbicides were investigated in field. The herbicides employed were butachlor, dithiopyr, pyrazolate(applied only for 8-day-old seedling), dithiopyr+pyrazolate, dithiopyr+ bensulfuron methyl), and butachlor+bensulfuron methyl(applied only for 20-and 35-day-old seedlings). There was no significant difference in plant growth, yield components and yield between the different-aged seedlings of the untreated check, except for the heading date, The heading date of 8-day-old seedling was delayed for 2 and 6 days as compared with those of 20-and 35-day-old seedlings, respectively. A very slight initial crop injury was found with the tested herbicides for all the different-aged seedlings. No significant differences in plant height and tiller number occurred between different-aged seedlings and the respective untreated check. All the herbicides used gave a good weeding effect. Yield components and yields were not affected by different-aged seedlings after application of the herbicides.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.307-314
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• 1984

One hundred winter wheat cultivars obtained from the world collections in Korea were planted in 1982. Stomatal frequency of flag leaf of these cultivars were measured, and among these 21 cultivars which showed different stomatal frequency were selected to investigate the relationship of their stomatal frequencies and other characters such as culm length, heading date and characters related to leaf. Stomatal frequency of flag leaf of 100 cultivars different significantly, ranging from 51 to 90 stomata mm$^{-2}$ for the adaxial and 35 to 65 for the abaxial surfaces of leaf. Stomatal frequency was always greater on the adaxial than on the abaxial surface. Mean ratios (adaxial/abaxial) were 1.5 for the flag leaf and 1.3 for the from second to fouth leaves. Among 21 cultivars examined, stomatal size which measured guard cell length varied from 38.5 to 46.6$\mu$ for adaxial surface and from 39.4 to 49.4$\mu$ for abaxial. A negative correlation was obtained between stomatal frequency and its size. Stomatal frequency decreased from flag (L$_1$) to lower leaves, progresively. Stomatal frequency on L$_1$ sheath was compared to those on L$_3$ and L$_4$ abaxial surface of leaf. More stomatal frequency on top and center of adaxial surface showed than that on basal part of a leaf but the abaxial surface resulted in reverse of adaxial one. Cultivars with high stomatal frequency on flag leaf showed higher stomatal frequency on the other leaves and sheaths. Positive correlation between stomatal frequency and other characters such as, culm length, heading date and chlorophyll content showed statistical significance, whearas it revealed the negative correlation of stomatal frequency with leaf weight, leaf area and stomatal aperture. However, no relation appeared between stomatal frequency and leaf vein.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.163-172
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• 1987

Results obtained from this study conducted to find the effect of wind-break net on reducing cold wind damage in the eastern coastal cold wind damaged area are summarized as follows. The rice critical safe heading date was up to Aug. 10 in the eastern coastal area, which the frequency of gale Aug. 10 to Sep. 10 is high. The frequencies of westries and cold wind from sea were 25%, respectively, in this area. The effects of wind-break net on reducing wind verocity were 26.9, 34,6% with raising air temperature of 0.4-0.7$^{\circ}C$ and water temperature of 0.3-0.5$^{\circ}C$. The effect of wind-break net was up to 10 time's distance of wind-break net's height from wind-break net. The installation of wind-break inhanced to rice growth, so showed the heading date earlier by 2-5days and increased culm length, no.of panicles per hill and no. of spiklets per panicle. The yield decrease in this area was due to sterilization, poor ripening and light 1,000 grain weight. The yields showed 20-28% increase by installation of wind-break net. The effect of wind-break net was most in the installation plot with wind-break net against cold wind from sea and westries installed in the panicle formation stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.483-488
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• 1997

This experiment was conducted to determine cutting time on the yield and nutritive value of brittle culm rice. Plant height and number of tiller were significantly different between variety and cutting time, and regrowth plant height and rate of regrowth tiller were tall and high at the early cutting. Early cutting increased crude protein, fat and NFE(Nitrogen free extract) content in the harvested foliage but crude fiber and ash content were decreased in the first cutting. Those of second cutting also showed reverse tendency. Fresh and dry matter yield were highest on heading date cutting, and those of KL501 were higher than those of Seomjinbyeo. TDN(Total digestible nutrients) content was higher with earlier cutting for initiated cutting, but that of second cutting was reversed. KL501 showed higher TDN content than Seomjinbyeo did at the any cutting time. TDN yield of heading date cutting was higher than that of the other cutting time.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.1
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• pp.25-34
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• 2010

Although whole crop barley (Hordeum vulgare L.) is now widely grown as a silage crop in Korea, forage production and silage quality of that for organic farm have not been published. Therefore, this experiment was conducted to evaluate the effect of harvest stage on forage production and quality of organic barley, and effect of field wilting and crushed rice for shortening of harvest date and improvement of forage quality. The experiment was split-plot design with three replications. Main plots were heading, milking and yellow stages, and sub-plot were field wilting for I day, crushed rice 10% (CR10%) and 15% (CR15%) treatments. The dry matter (DM) contents of heading, milking and yellow stages were 12.8%, 21.9% and 29.8%, respectively. The DM yields of heading, milking and yellow stages were 10,346, 15,819 and 18,336 kg/ha, respectively, and the total digestible nutrients (TDN) of these were 6,288, 9,550 and 10,178 kg/ha, respectively. The pH of milking stage showed low 4.00 pH values. The crude protein, ether extract, crude ash, non-fiber carbohydrate (NFC) and TDN contents were decreased as harvest stage progressed, while neutral detergent fiber (NDF) and acid detergent fiber (ADF) were increased. The crude ash (CA) of milking stage showed the lowest among harvest stages. Field wilting and crushed rice treatments decreased CA, NDF and ADF contents, and increased NFC and TDN contents. In vitro dry matter digestibility (IVDMD) decreased with progressed harvest stage, while field wilting and crushed rice treatments increased that of barley silage. Lactic acid and total organic acid contents of milking stage were the highest, and butyric acid of milking stage was the lowest among harvest stage. The good effect of field wilting and crushed rice was observed in heading stage. The experiment results indicate that optimum harvest stage of barley silage for organic was milking stage. The field wilting and crushed rice additive could be recommended as effective method for shortening harvest date and increasing forage quality of organic barley silage