• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.25 no.4
• /
• pp.86-90
• /
• 1980

To define the effect of planting time on the flowering of the peanut varieties, Cheonyup banlip and 9 other varieties were planted seven times at 15 day interval from April 15. The days to flowering of all peanut varieties were shortened proportionately with delayed planting time. The significant negative correlation (r =-0.86**) was recognized between the shortening rate of the days to flowering by later planting time and the days to flowering of peanuts planted at standard seeding time. The short day treatment did not have any effect on the chance of the days to flowering of each variety. A significant negative correlation was recognized between the number of flowers and the days to flowering of the peanut varieties planted at standard seeding time.

• The Korean Journal of Pesticide Science
• /
• v.2 no.3
• /
• pp.85-89
• /
• 1998

Effect of soil residue paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) on growth of barley (Hordeum vulgare L. cv. Sacheon No.6 and cv. Tapgolbori) and soybean [Glycine max (L.) Merr. cv. Alcheon and Danyeop] was investigated. Changes in soil residue paraquat during the cultivation period and residue amount in the p1ants at harvest were also determined. Experiments were conducted at two paraquat residue conditions; the first was done in an apple orchard soil where paraquat residue recorded 30.2 ppm in 1996, but decreased to about 9 to 9.8 ppm at the time of crop seeding and the second was conducted in the soil fortified to about 27 to 32 ppm paraquat residue. In both conditions, no crop injury due to the residue paraquat was observed and number of emerged seedlings and plant height of the two crops were not affected by soil residue paraquat. Residue amount of paraquat in the plants occurred less than 0.5 ppm detection limit. At the first condition, soil residue paraquat was further slightly decreased for 90 days after seeding, while no great change in the residue level was found at the second condition for 30 days after seeding. The results suggest that no carry-over effect occurs at about 30 ppm of soil residue paraquat and at present crop cultivation in Korean orchard soils are safe with respect to crop growth and paraquat residue in the plants.

• Development and Reproduction
• /
• v.12 no.1
• /
• pp.51-56
• /
• 2008

To optimize the cell culture conditions of zebrafish embryonic cells, we compared the efficiency of three types of medium, DMEM, K-NAC and D-NAC. In this study, we showed that the cells grown in K-NAC have better plating efficiency than DMEM, especially in the case of low cell seeding density. However, cells grew slower in K-NAC than those in DMEM in confluent cultures. The effect of 0.1% zebrafish embryo extracts was minimal. The presence of 1% trout serum in culture medium significantly increased the growth rate of cells(p<0.05). No difference was found at $2{\sim}3{\times}10^5$ cell seeding density(p<0.05). At $4{\sim}5{\times}10^5$ cell seeding density, cells grew better in DMEM than K-NAC (p<0.1). The results suggest that supplementation of NAC and A2P in Keratinocyte SFM may improves plating efficiency when cells are plated at low population. No difference was found for cell growth in either medium with 5%, 10% or 15% FBS supplemented (p<0.05). Cells culture in D-NAC grew significantly better than those in DMEM(p<0.05). Our results clearly showed that the use of NAC and A2P in the culture medium has a positive effect on cell growth regardless of the amount of FBS added.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.1
• /
• pp.141-154
• /
• 2012

This study was launched to verify the effective composition of plant species and its management program most suited for the dredged soiled area near Nakdong River Site 14. The improvement methods of planting base and the composition of plants such as silver grass, reed, and some colonies in aesthetic effect were studied. To search the management methods to decrease the confining pressure risen from the burried seeds which would consequently harm the previously seeded plants, experimental construction process was measured on the site. The purpose of this experiment was to figure out which part of the improvement on the plant base has the most significant effect for the revegetation of infertile, dredged soil, to verify the easily seeded, developing plants among seeded plants, and finally, to find the restoration model using plants near the dredged soil around riverside. 8 seeded plants and 23 invaded species were appeared which among the emerged plants, development of Aster yomena MAKINO, Lotus corniculatus var. japonica Regel, Trifolium repens L, and Dianthus longicalyx Miq were proved to be brought up well. Difference risen from the seed composition were not noticeable until 150day since the germination was proceeded mainly by Aster yomena MAKINO. The experimental plot with dredging sand+organic fertilizer method of construction and dredging sand+soil conditioner method showed most development while the effect of the plot with only the soil base of dredging sand stayed low. Another important method for the management of infertile, dredged soil base would be the removal of disturbing species which the experiment showed the tied relationship between the removal of disturbing species and development of seeding plants. Although this study was carried out focused on the Nakdong River Project, the study suggests the general management program that the removal of disturbing species such as Humulus japonicus Sieboid & Zucc. and Pueraria lobata (Willd.) Ohwi in times around rainy season(60days after seedling) would be effective for the easy growth of revegetation plants.

• Asian Journal of Turfgrass Science
• /
• v.18 no.4
• /
• pp.179-191
• /
• 2004

This study was conducted to find out the effect of sodding and seeding time and rate of seed mixtures on the establishment of cool-season turfgrasses by evaluating the turf coverage rates for two years. In fall planting, the required establishment period of full coverage($100\%$) was 1.5 months with a rolled turf sodding(Kentucky bluegrass $100\%$, Kentucky bluegrass $80\%$+perennial ryegrass $20\%$). The $100\%$ turf establishment was achieved in 7 months with Perennial ryegrass $100\%$, and 7.5 months by seeding with Kentucky bluegrass $100\%$(KB 100), Kentucky bluegrass $80\%$+perennial ryegrass $20\%$(KB80+PR20), Kentucky bluegrass $70\%$+perennial ryegrass $30\%$(KB70+PR30). In spring planting, the establishment periods far sod with KB 100 or KB80+PR20 were taken one month. However, in the case of seeding, the establishment periods were 3 months, 3.5 months, 3.5 months and 4 months with PR100, KB80+PR20, KB70+PR30, and KB 100, respectively Comparing the turf establishment vigor between fall and spring planting, the vigor was higher In spring planting than in fall planting in both sodding and . seeding. In the case of spring planting, the most proper time for turf establishment was tested on April, May, and June trials. The effect was significant in establishment vigor. The result showed highest on April planting. On May and June trials, establishment vigors were decreased gradually As the mixture rate of PR increased, ryegrass, establishment vigor was decreased with the rates. These results indicated that perennial ryegrass has relatively less tolerant to summer heat than Kentucky bluegrass. Number of shoots in 95 days after seeding was higher in KB100 by 16,600 per $m^2$ than in PR100 by 12,400 per $m^2$, while the lowest number showed in KB50+PR50 by 3,300 per $m^2$. Those in KB80:PR20, KB70:PR30 were 6,700 and 4,900 per $m^2$, respectively. The ratios of tillers according to mixture rates between Kentucky bluegrass and perennial ryegrass were KB80:PR20=87:13, KB70:PR30=78:22, and KB50:PR50=48:52. According to results in this study, Ideal seeding time might be spring (April) than in fall (September), and proper mixture rate was $80\%$ of Kentucky bluegrass with $20\%$ of perennial ryegrass.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.66 no.4
• /
• pp.419-427
• /
• 2021

In South Korea, direct seeding of rapeseed (Brassica napus L.) is difficult during spring cultivation in early March because of the low yield production associated with late flowering and poor seed quality. To compare the period of direct sowing, the present study investigated the growth characteristics of rapeseed according to planting dates. Specifically, 35 day-old seedlings were transplanted or directly sown on four different dates (late February, early March, late March, and early April) in 2020 and 2021. As the planting date was delayed, the days to flowering of rapeseed decreased. Similarly, the plant height, seed set percentage, and seed yield of rapeseed were reduced upon delay in planting. The seed yield of rapeseed through direct seeding in late February was the highest, 2.76 ton·ha^-1. On all seeding dates, except for late February, the transplanted rapeseed produced a higher yields than the directly seeded rapeseed. The crude oil and oleic acid content, which is related to the quality of rapeseed, decreased with the delay in planting dates, and this decrease was greater, with the direct seeding of rapeseed depending on the sowing time. In the correlation analysis, the planting date was significantly and negatively correlated with the yield, crude oil content, and oleic acid content of the transplanted rapeseed, while the sowing date was negatively correlated with the plant height, silique size, yield, and seed quality of the directly seeded rapeseed. Finally, the effect of planting date on rapeseed growth was stronger in direct seeding than in transplanting. Therefore, during spring cultivation after late February to early March, transplanting, rather than direct seeding, in more advantageous in terms of seed quality and yield.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.1
• /
• pp.68-76
• /
• 1996

To elucidate the optimum fertilizer level and application method for band application under puddled-soil drill seeding in Jeonbuk series of fluvio-marine alluvial soil at National Honam Agricultural Experiment Station in 1995, using Dongjinbyeo, slow releasing compound fertilizer of 100％ and 80％ to conventional application level was applied totally as basal fertilizer simultaneously with seeding under 3cm and 5cm depth from soil surface in a distance of 4cm from the seeded row. Plant height was taller and tiller number was higher in band application than conventional application but ratio of effective tiller was vice versa. Panicle number was more but ratio of effective tiller ratio was lower in 100％ than 80％ level of band application and they were higher in 3cm than 5cm depth from soil surface. Leaf area index and dry weight was higher in conventional application at early growth stage but was vice versa after maximum tillering stage, and they were higher in 3cm depth at early growth stage but 5cm depth after maximum tillering stage. NH$_4$-N in soil was higher in conventional application at 25 days after seeding but, thereafter was lower than band application and it was higher in 3cm than 5cm depth till 40 days after seeding but was versa, thereafter. Lodging degree was slightly higher in band application, 100％ level and 5cm depth than in their counterparts. Panicle number and grain number per $m^2$ was lower in conventional application than 80％ or 100％ level of band application without significant difference between band application levels or application methods. Yield was higher at 80％ level of band application under 3cm depth than conventional application, but no significantly different among other application methods. Therefore, 80％ level of band application under 3cm depth of soil surface was more effective for puddled-soil drill seeding on the basis of the reduction of application efforts, better plant growth and higher yield in rice.

• Korean Journal of Agricultural Science
• /
• v.2 no.2
• /
• pp.331-339
• /
• 1975

This experiment was carried out to obtain some imformations about the ecological variations of the heading time of the newly breeded Indica x Japonica varieties/pedigrees according to the seasonal changes of the seeding date. day length and temperature. The results obtained are summarized as follows; 1) At all varieties. days to heading showed a straight reduction according as the seeding time was delayed. 2) At the group of Japonica varieties. the days to heading of early maturing varieties were much shortened and that of medium or late maturing varieties were little or not shortened under high temperature condition but at the group of Indica ${\times}$ Japonica va rieties/pedigrees. days to heading were significantly elongated under high temerature condition. 3) At the group of Japonica varieties. the effect of the short day condition on the days to heading was significantly high at the medium and the late maturing varieties than at the early maturing varieties. however. the short day effect on the reduction of days to heading was not related with the earlyness of each varieties at the group of Indica ${\times}$ Japonica varieties/pedigrees. 4) Days to heading of all varieties under the high temperature condition were longer than that under the ordinary culture. On the other hand, the days to heading of Japonica varieties under the short day treatment were shorter than the days to heading of ordinary culture but at the group of Indica x Japonica varieties/pedigrees. the days to heading under the short day treatment were longer than ordinary culture. 5) At both varieties groups. the days to heading at each seeding time were significantly correlated with days to heading at ordinary cultivation. fl) At the group of Japonica varieties. relatively high correlation(p=0.1) was recognized between the days to heading by delay of seeding time, but at the group of Indica ${\times}$ Japonicava rieties/pedigrees, correlation between the ordinary heading date and the shortening rate of days to heading was very low.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.35 no.1
• /
• pp.17-25
• /
• 2015

The following experiments were used to evaluate the effect of seeding method and pre-emergence herbicides on weed control and the production of the $sorghum{\times}sudangrass$ [sorghum bicolor (L.) Moench] hybrid under field and in vitro conditions. Under the in vitro condition, we evaluated how different kinds of herbicides affect the rate of seed germination and the growth of early seedlings in the $sorghum{\times}sudangrass$ hybrid treated with herbicides. Simazine, alachlor, and methabenzthiazuron were used, and their concentration levels were 0%, 40%, 70%, and 100%. The germination ratio of the seeds was reduced by the application of simazine, methabenzthiazuron, and alachlor compared with the control (distilled water). The alachlor application severely decreased the sorghum germination ratio. However, seed germination was not greatly influenced by the concentration level of the herbicides. Root and shoot length were increased in the following order: control > simazine > methabenzthiazuron > alachlor. Overall, alachlor significantly reduced root length more than shoot length. The differential tolerance of the $sorghum{\times}sudangrass$ hybrid to pre-emergence herbicides by seeding method was then tested under the field condition. The plants were severely injured by the alachlor application, leading to a great reduction in the number of stems. However, for the simazine and methabenzthiazuron applications the number of stems lost was slightly lower than it was for the alachlor and simazine + alachlor applications. In the seeding method, drilling was more effective in reducing herbicide injury than broadcasting. All of the herbicides effectively controlled weeds. The simazine and methabenzthiazuron applications showed a significantly higher dry matter (DM) yield. However, the alachlor and simazine + alachlor applications severely reduced the DM yield. This result suggests that the alachlor application has a significant effect on plant production. Similarly, the total digestible nutrient (TDN) yield was greatly reduced by the alachlor and simazine + alachlor applications. From the results presented above, we concluded that the yield of DM was the highest for broadcasting with no herbicide. and drilling was the most-effective way to reduce herbicide injury. The simazine application was the most-effective herbicide, showing the highest forage yield and TDN yield.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.9 no.2
• /
• pp.68-76
• /
• 1989

The effect of characteristic of mixture sowing combination on the development of botanical composition was conducted for 12 years on the meadow experiment. The results of this study were summarized as follows. 1. Festuca pratensis lost the expected position of a dominant species. Its vegetation ratio decreased gradually until the last survey year. 2. Arrhenatherum elatius, known as a typical 2-cutting grasss, developed to a dominant species only in the 3- cutting plot without limitation. 3. Alopecurus pratensis, whose feeding value diminishes rapidly, developed to a dominant species regardless of N-fertilization under the condition of 3-cutting, even though the same small amount of seeding was introduced as usual. 4. Trisetum flavescens which causes calcinose exceeded the 40% of vegetation ratio which was the approved rate for feeding at the high N-level (2OOKgIha). 5. Among the introduced, the species showed the significance in quantity were Lotus corniculafus solely in the 2-cutting plot, and Trifolium repens solely in the 3-cutting plot. In the 3-cutting plot legume yet remained under N-fertilization. 6. The appropriate ratio of vegetation for the subordinate species in the mixture sowing combination was easily attained from the least amount of seeding (Gramineae with max. 3Kg/ha, Leguminosae with max. 2kgIha). 7. Into the mixture sowing combination, infiltrated unintroduced species marked more noticeably in the 2- cutting plot than in the 3-cutting plot.