• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.5 no.4
• /
• pp.1-9
• /
• 2002

This study is carried out to make the environmentally affinitive porous planting block for revegetation and to make a effective program for greening plans. The summary is shown below. 1. In order to get stronger intensity and distribute proper porosity in the block for planting, the cements mixed with fine soil were used and the finer in soil grains gives the stronger in intensity of the cements. Use of the furnace slag cements instead of the portland cements showed relatively stronger in intensity of the block. The intensity of the block became stronger when the mixed ratio of the cements to soil is 5 : 1, but the pore space ratio was lower. The percolate pH of the portland cements after one month of treatment was 13.1 but the percolate pH of the furnace slag cements was shown lower. To mold proper porous planting blocks, the proper combination of additives such as the dehydrating agent, elastic agent and adhesives into the mixture of cements and soil gives better effectives. 2. After molding the porous planting blocks, it gave a better result when the grains of the filler made of peat moss, upland soil and compound fertilizer were smaller than 2 mm in size. Shaking of the filling materials also gave the better result, but it took more time and cost much more. Therefore, it was better when the filling materials were mixed with water first then flew down for stuffing. 3. It was necessary to cover with soil after seeding or planting on the porous planting blocks. The proper thickness of the soil to help root development and keep moisture is about 3~5 cm. 4. The plants for planting on the porous planting block were required stronger in the growth condition of their roots and their environmental adaptability. The average germination percentage and rate of Platycodon grandiflorum on the porous planting block were 88.8% and 85% accordingly and their rate is very uniform. The germination rates of Dianthus superbus var. longicalycinus and Taraxacum officinale were more than 50%. These grass species, Chelidonium majus var. asiaticum, Lysimachia mauritiana and Scabiosa mansenensis were the suggested biennial grasses in the planting area where exchanging of the seedling or nursery plants was not necessary because their germination rates were 59.3, 45.6 and 40.3% accordingly. Viola kapsanensis, Chrysanthemum sp., Taraxacum sp. and Iris ensata var. spontanea are the grass species that could be used by seeding for greening. However, the germination rate of Solidago virga-aurea var. asiatica, Aster scaber and Lythrum anceps were lower than 10%. The coverage ratio of Ixeris stolonifera is more than 80% after 60 days seeding and the root length of most of species are more than 10 cm except Iris ensata var. spontanea and Platycodon grandiflorum because their root developed thicker than other species.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.s02
• /
• pp.66-80
• /
• 1989

Salt injury in rice is caused mainly by the salinity in soil and in the irrigated water, and occasionaly by salinity delivered through typhoon from the sea. The salt concentration of rice plants increased with higher salinity in the soil of the rice growing. The climatic conditions, high temperature and solar radiation and dry conditions promote the salt absorption of rice plant in saline soil. The higher salt accumulation in the rice plant generally reduces the root activity and inhibits the absorption of minerals of rice plant, resulting the reduction of photosynthesis. The salt damages of rice plant, however, are different from different growth stage of rice plants as follows: 1. Germination of rice seed was slightly delayed up to 1.0％ of salt concentration and remarkably at 1. 5％, but none of rice seeds were germinated at 2.5％. This may be due to the delayed water uptake of rice seeds and the inhibition of enzyme activity, 2. It was enable to establish rice seedlings at seed bed by 0.2％ of salt concentration with some reduction of leaf elongation. The increasing of 0.3％ salt concentration caused to the seedling death with varietal differences, but most of seedlings were death at 0.4％ with no varietal differences. 3. Seedlings grown at the nursery over 0.1％ salt, gradually reduced in rooting activity after transplanting according to increasing the salt concentration from 0.1％ up to 0.3％ of paddy field. However, the seedlings grown in normal seed bed showed no difference in rooting between varieties up to 0.1％ but significantly different at 0.3％ between varieties, but greatly reduced at 0.5％ and died at last in paddy after transplanting. 4. At panicle initiation stage, rice plant delayed in heading by salt damage, at meiotic stage reduced in grains and its filling rate due to inhibition of glume and pollen developing, and salt damage at heading stage and till 3 weeks after heading caused to reduction of fertilization and ripening rate. In viewpoint of agricultural policy the overcoming strategy for salt injury is to secure sufficient water source. Irrigation and drainage systems as well as underground drainage is necessary to desalinize more effectively. This must be the most effective and positive way except cost. By cultural practice, growing the salt tolerant variety with high population could increase yield. The intermittent irrigation and fresh water flooding especially at transplanting and from panicle initiation to heading stage, the most sensitive to salt injury, is important to reduce the salt content in saline soil. During the off-cropping season, plough and rotavation with flooding followed by drainage, or submersion and drainage with groove could improve the desalinization. Increase of nitrogen fertilizer with more split application, and soil improvement by lime, organic matter and forign soil addition, could increase the rice yield. Shift of trans-planting is one of the way to escape from the salt injury.

• Research in Plant Disease
• /
• v.13 no.2
• /
• pp.104-109
• /
• 2007

Pink root disease of onion, a known worldwide constraint upon onion production, significantly reduces crop levels in the main Korea cultivation area. In order to examine the effect of flooding on incidence of pink root disease caused by Pyrenochaeta terrestris and on onion growth and on populations of soil fungi, field experiments were conducted during two seasons, 2003/04 and 2004/05 at Onion Research Institute. Populations of soil fungi from fields were assayed on selective media. Flooding treatment was effective in reducing populations of P. terrestris, Pythium spp., and Rhizoctonia sp. in soil; fungal populations in soils flooded for 90 days were reduced to 1/2 to 1/3 of those in non-flooded soils. In nursery bed, protective activities of soils flooded for over 60 days were 93.5 to 99.2% and their pink root incidences were less than 5%, which were 1/11 to 1/18 of that in control. Increased yield of onion bulbs was associated with control of soil borne pathogenic fungi by flooding treatments. As flooding period was prolonged, bulb grade showed the tendency to increase. Soil flooding for over 60 days resulted in effective disease control, facilitated accurate planning of plant population in the field, extension of the growing-season and consequently higher yields of better quality.

• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.1
• /
• pp.50-55
• /
• 1986

To get the basic information about ginseng seedling production, yields of ginseng seedling and soil physico-chemical components in 32 fields of Yang-Jik and 19 fields of Ban-Yang-Jik nursery were investigated. Germination rate is $78.5{\pm}3.0%$, $77.8{\pm}2.8%$ in Yang-Jik and Ban-Yang-Jik. Rate of number of mature seedlings to number of seeds planted is $62{\pm}13.5%$, $53{\pm}12.6%$ in Yang-Jik and Ban-Yang-Jik. Rate of number of available seedlings to number of seeds planted (Rate of available seedling) is $42{\pm}12.5%$, $26{\pm}12.1%$ in Yang-Jik and Ban-Yang-Jik. The number of available seedlings per Kan (Kan means $180{\times}90cm$ area) is $627{\pm}187$, $368{\pm}182$ in Yang-Jik and Ban-Yang-Jik. Rate of number of unusable seedlings to number of mature seedlings is 34%, 51% in Yang-Jik and Ban-Yang-Jik. It showed the negative correlation between amount of coarse sand and stem height, and central leaf length, on the other hand, possitive correlation between amount of extremely fine sand, and stem height, and central leaf length respectively. Rate of available seedling was positively correlated with amount of medium, fine and extremely fine sand, whereas negatively correlated with amount of coarse sand in Yang-Jik. Root weight per seedling was positively correlated with amount of medium, fine and extremely fine sand. Contents of organic matter, available phosphate and potassium in Ban-Yang-Jik were higher than those of Yang-Jik, but content of lime was higher in Yang-Jik compared to that of Ban-Yang-Jik. Possitive correlations were showed between leaf area per seedling and content of organic matter, and between stem height and content of lime in Yang-Jik. Root weight per seedling was positively correlated with content of organic matter and magnesium in Ban-Yang-Jik, but there is no correlation between any of soil chemical components and root weight in Yang-Jik.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.4
• /
• pp.218-224
• /
• 2001

To find out the optimum level of slow release N fertilizers (MS 10, MS S10, LCU 80, and LCU 100), total amount of nitrogen required throughout the growing season were applied in the seedling box or incorporated into paddy soil. Four levels of the slow release N fertilizers (0, 6, 9 and 12 kg N/10 a) were mixed with commercial rice nursery bed soil. N release rate and electrical conductivity(EC) of the slow release fertilizers were greater in the order of MS 10 > LCU 80 ${\fallingdotseq}$ LCU 100 > MS S10 and higher as temperature increased. No seedlings were emerged in all MS 10 plots. The seedling emergence rate of LCU 80 and LCU 100 decreased as the N level increased and seedlings were wilted severely on the 13th day after sowing at 9 and 12 kg N/10 a. In MS S10 plots the emergence rate was higher than 80% at all N levels and seedling growth was normal until 30 days after sowing. Yield of rice was similar between seedling box application and soil incorporation in paddy of MS S10. Yield of rice among the 6, 9, 12 kg N/10 a of MS S10 and conventional 12 kg N/10 a of urea split application was similar, but it was significantly higher compared with no N plot. Fertilizer N recovery of MS S10 decreased as fertilizer level increased and it was significantly higher compared with conventional urea split application.

• Research in Plant Disease
• /
• v.16 no.3
• /
• pp.279-284
• /
• 2010

Clubroot caused by Plasmodiophora brassicae is a widespread disease that causes serious problems in many brassica growing areas. To establish more simple and reliable clubroot screening method of Chinese cabbage to P. brassicae using soil-drenching inoculation, the development of clubroot on Chinese cabbage according to several conditions such as soil type, inoculum concentration of P. brassicae GN-1 (race 9), plant growth stage and incubation period was studied. In a commercial horticulture nursery media soil (CNS), disease severity of the seedling according to inoculum concentration increased in a dose-dependent manner, but did not in mixture of CNS and upland soil (1:1, v/v). To facilitate and acquire precise result of resistance screening of Chinese cabbage to clubroot, 10-day-old seedlings should be inoculated by drenching the spore suspension of P. brassicae to give inoculum density of $4.0{\times}10^8$ spores/pot. To develop the disease, the inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days, and then cultivated in a greenhouse ($25{\pm}5^{\circ}C$) for five weeks. Under the optimum conditions, 25 clubroot-resistant (CR) and 3 clubroot-susceptible (CS) cultivars were tested for resistance to P. brassicae. All CR cultivars showed very clear resistance response, on the other hand all CS cultivars severly infected with the pathogen. The results suggest that this method is efficient screening method of Chinese cabbage for resistance to clubroot disease.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.2 no.2
• /
• pp.43-52
• /
• 1999

This study was carried out to verify results of the nursery seedbeds. From November of 1997 to September of 1998, the artificial banking slopes in the greenhouse of the College of Agriculture and Life Sciences, Seoul National University were seeded with the mixtures of those species. Most of exotic species showed relatively poor development of root as short as 30cm. Also the green weight of root biomass of the native species was more than two times than that of the exotic species. On the other hand, it was found that the exotic species have relatively well-developed fine roots. Thus, it was concluded that the seed-mixture of the native species with long and thick roots and the exotic species with fine roots be the most effective method for topsoil erosion control on banking-slopes. The artificial rainfall system treatment(30mm/hr, 60mm/hr, 100mm/hr) on $30^{\circ}$ banking-slopes did not cause any significant change in the amount of soil loss by erosion. The root system was best developed in the plot of 1,000 seedlings per square meter and it performed well for soil erosion control. Consequently, in the case of seeding of single herbaceous species without mixing any woody seeds, the expected seedlings were 1,000 to 2,000 per square meter.

• Korean Journal of Plant Tissue Culture
• /
• v.28 no.5
• /
• pp.273-276
• /
• 2001

In order to develop effective acclimatization methods for Aralia elata plantlets regenerated from somatic embryos, various acclimatizing conditions were compared regarding both survival rate and growth of the plantlets. The plantlets were transplanted into plastic boxes containing artificial soil in the presence of either several levels of MS liquid media, distilled water, 2% sucrose or 0.1% hyponex solution. They were then cultured by spraying of distilled water twice a week and maintained in the normal tissue culture room. Perlite was proved to be better than vermiculite on survival rate and growth of the plantlets. As the size of perlite (larger than 0.2 cm in diameter) increased, both the survival rate and growth of the plantlets improved. Among the various MS liquid media and different aqueous solutions tested, distilled water appeared to result in the best survival rate and growth. MS media were also effective in increasing survival rate and supporting growth when diluted to 1/4 and/or 1/8. The acclimatized plantlets could be transplanted directly onto the nursery bed and grown normally. The above results suggest that plantlets regenerated from somatic embryos of Aralia elata be effectively acclimatized using a plastic box containing perlite with distilled water treatment.

• Korean Journal of Environment and Ecology
• /
• v.9 no.1
• /
• pp.56-61
• /
• 1995

To examine the effects of gibberelin treatment on seed germination of six wild herbaceous species -Dicentra spectabilis, Aster pekinensis, Agastache rugosa, Elsoholtzia ciliata, Boehmeria tricuspis and Pulsatillia cerrma var. chaerophyiloides - in Kangwon-do, pretreated seeds of five species were sowed on plastic pots with mixed soil(sand：peat moss：perlite： vermiculite, 1：1：1：1, v/v) in 23,April 1995. Seeds were soaked in 25,50 ppm gibberelin solution and ground water during 24 hours. Pretreated seeds of Pulsatiilia cerrma var. chaerophylloides were sowed on nursery soil in 1, June 1995. Seed pretreatments in 31, May 1995 were same method. Seed germination rate was measured and compared among species and treatments. Seed germination rate of Dicentra spectabilis, Agastache rugosa and Elsoholtzia ciliata was differed higly significant among pretreatments ,but those of that of Aster pekinensis, Boehmeria tricuspis and Pulsatillia cerrma var chaerophylloides did not significant at 5% level. Gibberelin pretreatment raised seed germination rate of Dicentra spectabilis and Agastaohe rugosa and proper concentration of GA$_3$ was 25ppm and seed germination rate of Elsoholtzia ciliata was highest at GA$_3$ 50ppm plot. The utilization of wild herbaceous species were discussed.

• The Korean Journal of Mycology
• /
• v.43 no.3
• /
• pp.180-184
• /
• 2015

For selection of effective antagonists for control Sclerotinia rot of lettuce, 29 bacteria were isolated from soil in Korea. The bacterial isolates M27 and RM43 identified as Bacillus sp, were selected as prospective agents for inhibiting mycelial growth of Sclerotinia sclerotiorum and Sclerotinia minor. Among the selected isolates, Bacillus amyloliquefaciens M27 effectively suppressed incidence of Sclerotinia rot by Sclerotinia sclerotiorum and Sclerotinia minor in the lettuce nursery.