• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.36 no.2
• /
• pp.127-133
• /
• 1991

Experiments were conducted to investigate the effect of light shading around the heading stage on grain yield and its components of rice. Early, medium, and late-maturing varieties were trected with the light shading of 50% and 75% from the reduction division stage to 20 days after heading date. Heading date were delayed 2-3 days, whereas the mid -late varieties, Sangpung- byeo, and Bongkwang- byeo were no significantly affected. Culm length was increased and panicle exsersion was reduced as the shading treatments become higher, and the degree of the shading effect was more intensive at 75% of shading. The rate of spikllet degeneration was higher at the secondary rachis branches than the primary rachis branch. The early maturing varieties showed the higher rate of spikelet degeneration. Spikelet number was reduced 12-15, spikelet sterility was increased and ripening rate was declined by the shading treatments. Grain yield was decreased by 30-40% at the shading treatment of 50%, and 50% at the shade treatment of 75%.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.3
• /
• pp.181-184
• /
• 2000

This study was carried out to investigate the influence of barley yellow mosaic virus(BaYMV) on agronomic characters in naked barley. A naked barley cultivar, Beagdong was evaluated for disease systems at naturally infected field, National Honam Agricultural Experiment Station. SPAD value of the infected plants by BaYMV was low as compared to healthy plants. Heading time was delayed by 10-11 days. Dry matter weight per plant, culm length, and number of spike per plant were reduced in the infected plants by 75%, 68%, and 49%, respectively. Length of internode was reduced in the first to the sixth internode from the upper part, especially, that in the third to the fifth internode was mostly reduced by 75-80%. Also, length of awn, number of kernels, 1000-kernel weight, and kernel weight per plant of the infected plant were reduced by 17-19%, 47%, 60%, and 78%, respectively. Lightness and redness for kernel color value of Baegdong were low and high, respectively.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.22 no.4
• /
• pp.247-252
• /
• 2002

“DK 537”has been selected by forage crop breeding team at the National Livestock Research Institute(NLRI), RDA and has been determined by the Deliberative Council of the National Agricultural Cooperative Federation(NACF) in 2002, as a new recommended hybrid which is early maturing, good quality and hi호 yield of corn for silage. The characteristics of this hybrid are as follows ; 1. The seed coat is yellow and the mean of tasseling date is 5th of July, included in early maturing hybrid which is one day delayed than check cultivar, DK 501. The culm length is 246cm. It is resistant to lodging because of its low height from surface to ear. 2. DK 537 shows resistance to H. maydis and Maize Black-Streaked Dwarf Virus(MBSDV). It also shows strength to corn borer as much as DK 501 does. 3. Fresh yield. dry matter yield. and TDN per a ha are 50 tons, 16.9 tons, and 11.4 tons respectively. which are almost same yielding level of DK 501. Its percent ear to total dry matter is 50.8% at the same time. Through all these tests, we could make sure at DK 537 hybrid will be recommended as good forage crop.

• Journal of the Korean Wood Science and Technology
• /
• v.15 no.4
• /
• pp.26-31
• /
• 1987

The ultraviolet and infrared spectra of dioxane lignin from bamboo were investigated. 1. Spectrum curve type considerably resembled that of wood lignin. There were 3 absorption peak positions at 210nm(max. peak), at 260-270nm(shallow mini. peak), at 280nm(lower max. peak) as in the wood lignin spectra. 2. The lower minimum peak near at 280 nm is the typical peak of lignin. This peak does not exist exactly at 280 nm but from 282nm to 285nm in this bamboo UV spectra. The absorption intensities are equal in this region and the peak is not sharp. 3. The absorption band of aromatic nucleus is near at wave number $1550cm^{-1}$ in the IR spectra of bamboo lignin. The intensity at about 1040-$1130cm^{-1}$ and at about 1230-$1275cm^{-1}$ were similar in the hardwood lignin but reverse to that of softwood lignin spectrum.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.5 no.3
• /
• pp.208-212
• /
• 2003

Extended light illumination by street lamp and automobile light has provoked problem in farmland. Night break was imposed by incandescent lamp (50∼60 lux) for 10 minutes every three hours during 12 hours dark period increased culm length compared to continuous dark of 12 hours, and decreased the number of grains per spike in rice. However, these characters were increased by 12 hours dark period with and without night break as compared to 9 hours continuous dark condition. Compared to 12 hours continuous dark condition, night break delayed heading by 9 and 26 days and 9 hours continuous dark condition delayed it by 47 and 41 days in Ilpumbyeo and Hwaseongbyeo, respectively. Night break increased stem length and node number, while decreased pods of soybean cultivar Hwanggeumkong. The stem length and node number were increased by 9 hours continuous dark condition compared to 12 hours dark condition with and without night break. Compared to 12 hours continuous dark rendition, night break delayed flowering by 4 days and to 9 hours continuous dark condition by 19 days.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.6
• /
• pp.554-559
• /
• 1993

This experiment was carried out at Chuncheon substation, Crop Experiment Station to investigate the effect of cold water irrigation on the growth and grain yield of rice in 1990. Irrigation of cold water (17$^{\circ}C$) delayed 10 to 19 days of heading, and reduced about 17 to 31% of plant height in terms of culm and panicle length. Number of panicle per plant was decreased and / or increased by cold water irrigation. Cold water irrigation reduced spikelet number per panicle and percent of filled grain. Grain yield was increased but, straw weight was decreased according to water temperature gradient from inlet to outlet. There was varietal differences in head rice recovery by cold water treatment. In general the dark brown and / or black colored kernel increased at cold water inlet but decreased percent of green kernel. Alkali digestible value increased and amylose content decreased at cold water inlet.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.44 no.3
• /
• pp.191-196
• /
• 1999

In rice-barley cropping systems, efficient utilization of barley straw is essential, both to improve the soil fertility and to conserve the environment. In order to identify the effects of barley straw mulch rates in rice cultivation, a rice cultivar, 'Gancheogbyeo', was directly seeded on a no-tillage field synchronized with barley harvesting with five barley straw mulch rates, i.e., 0, 2.5, 5.0, 7.5 and 10.0 ton h $a^{-1}$ and agronomic characters of rice and soil nitrogen were determined. The increasing of barley straw mulch rates. Dominant weed species, chestnut, occurred in large amounts in no mulching or lower mulch rates than in higher mulch rates. The content of N $H_4$$_{＋}$-N in soil applied with high barley straw mulch rates was lower during the month after seeding, and then it was higher at heading date, compared with lower mulch rates or no mulch plot. As the barley straw rate increased, maximum tillering stage was delayed, and plant height was reduced. Although the lodging of rice plants was seldom observed in all plots, the breaking strength of the culm was significantly higher in the mulch rate of 10.0 ton h $a^{-1}$ . With an increase of barley straw mulch rate, the effective tillering rate and spikelet number $m^{-2}$ decreased while ripened grain ratio increased. The rice grain yield was slightly decreased with an increase of barley straw mulch rate, although significant differences were not found all barley straw mulch rates. These results suggest that there is no significant yield loss although the total barley straw production, approximately 5.0 ton h $a^{-l}$ in the present study, apply in the paddy for the following rice cultivation by no-tillage direct seeding.ect seeding.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.36 no.1
• /
• pp.52-56
• /
• 1991

In 1986, at Cheju and Seoguipo, a sweet com hybrid, Golden Cross Bantam 70, was grown at 5 phosphate rates (0, 8, 16, 24 and 32 kg/l0a) to determine effects of phosphate rate on growth and yield of sweet com and to recommend the optimum phosphate rate for sweet com production in volcanic ash soils of Cheju province. Days to silking were shortened 1 to 2 days by phosphate application of more than l6kg/10a. Culm length, ear height and fresh stover yield/l0a did not differ between two locations, but linearly increased as phosphate rate was increased from 0 to 32kg/10a. Average length and weight of marketable ears were greater at Cheju than at Seoguipo and linearly increased as phosphate rate increased. The number of marketable ears per plant and per l0a did not differ between two locations, but quadratically increased as phosphate rate increased. The economic optimum phosphate rate estimated on the basis of the quadratic model, ranged 25.6 to 27.4kg/10a at various fertilizer-to-ear price ratios.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.2
• /
• pp.130-136
• /
• 2006

Growth and quality of rice are affected by various factors including the location of cultivation. This study was conducted to investigate the effects of altitudinal locations on the growth and yield-related components of rice. Nineteen Japonica type varieties were grown at Iksan (altitude, 10 m), Imsil (altitude, 150 m), Jinan (altitude, 275 m) and Jangsu (altitude, 430 m) at a similar latitude in Jeonbuk province in the south western Korea. Minimum air temperature showed a strong negative correlation with altitude. The morphological traits and yield-and quality-related components were analyzed. Longer days to heading was required at higher altitudes. However, culm length, panicle length, panicle number, grain number and rice yield were reduced at higher altitudes. Protein content of brown rice increased but fatty acid content decreased at higher altitudes. Amylose content was affected by neither the altitude nor the ecotype. Palatability of polished rice tends to be improved at higher altitudes and in early-maturing ecotypes but its relationships with altitude and ecotype were not significant. Head rice ratio was lower at higher altitudes but broken rice ratio vise versa. These results indicate that growth and quality of rice are affected significantly by changes in temperatures at the locations of different altitude. Also, the characters related to yield and quality of rice often respond incompatibly to the changes in altitudes. These results could provide valuable information for the strategic planning of rice production in geographically diverse areas.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.11 no.2
• /
• pp.10-18
• /
• 2008

In this study, about 80 Kentucky bluegrass (Poa pratensis L.) ecotypes native to Korea were collected annually to analyze their morphology and growth characteristics from 1995 to 2007. Kentucky bluegrass ecotypes with superior characteristics of 'Pureundle' (Trial No. : P38), 'Sewon' (P77), 'Inje' (00034), 'Donggang' (00052), 'Hwasun' (01001), 'Pyengchang' (01071), 'Kongju' (02006), 'Chungsong' (02077), and 'Kumsan' (03005) and three foreign cultivars were transplanted to flowerpots in May 8, 2006 in order to analyze the blooming and morphological characteristics. Out of the selected superior ecotyes, six were collected on the roadsides, two were collected around paddy or dry fields, and one was collected at riverside. Length of 1st internode of 'Chungsong' was the longest (30.7cm), that of 'Pyengchang' was the shortest (12.8cm), and ecotypes showed variation in length. The 1st angle of branches of 'Donggang' was the narrowest ($141.7^{\circ}$), that of 'Hwasun' was the widest ($188.3^{\circ}$), and that of the introduced foreign cultivars were between $159.3^{\circ}$ and $166.7^{\circ}$. The number of nodes of the introduced cultivars were same (six), while that of Korean ecotypes were four to six. Length of flowering culm of 'Chungsong' was the longest (50.7cm) and while that of 'Pyengchang' was the shortest (19.2cm). 'Donggang' with the highest seed yield showed relatively high (36.8cm) inflorescence height when compared to other ecotypes. The five ecotypes of 'Sewon', 'Inje', 'Donggang', 'Pyengchang', and 'Kongju' were investigated to have relatively wide leaf width. Especially 'Sewon' and 'Inje' were investigated to have wide leaves of 4.5mm and over.