• Journal of The Korean Society of Grassland and Forage Science
• /
• v.23 no.1
• /
• pp.13-22
• /
• 2003

This pot experiment was conducted to find out the forage productivity and mineral contents in an orchardgrass sward affected by the compost, lime, and phosphorus applications on the newly reclaimed and arable pasture soils. This 3rd part was concerned with the effect of phosphorus application($P_{0}$ : control, $P_1$=1.25ｇ, $P_2$=2.50g, $P_3$=3.75g $P_2$$O_{5}$ pot). The results obtained are summarized as fellows; There were considerable differences between the newly reclaimed and arable pasture soils in the soil chemical characteristics as follows in general; poor~common in the newly reclaimed soil and common~good in the arable pasture soil in terms of soil fertility standard. Comparing with the arable pasture soil, the contents of available$ P_2$$O_{5}$ / in the newly reclaimed soil at end of experiment were considerably increased by the $P_2$$O_{5}$ applications, These effects in the newly reclaimed soil were positively influenced by the additional application of compost, but were adversely influenced by the additional application of lime. The seedling vigour and yield of orchardgrass were far better in the arable pasture soil than in the newly reclaimed soil. At the $P_{0}$ treatment, those were very poor in 也e newly reclaimed soil, but were good in the arable pasture soil. Comparing with $P_1$ treatment, the above effects of heavy $P_2$$O_{5}$ / applications($P_2$and $P_3$) were not recognized. On the newly reclaimed soil, the above effects were markedly enhanced by the applications of $P_2$$O_{5}$ with compost. The Ca, Mg, and P contents of orchardgrass were relatively higher on the arable pasture soil than on the newly reclaimed soil, whereas ere were no differences in the K contents.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.23 no.1
• /
• pp.31-36
• /
• 2003

This pot experiment was conducted te find out the effects of kieserite application ($T_1$; control, $T_2$; standard amount of $N-P_2$$O_{5}$ $-K_2$0, $T_3$; $T_2$+ kieserite) on the seedling vigour and yield of pass/clover mixed swards on newly reclaimed hilly soil. The results obtained are summarized as follows: At the $T_1$ treatment the seedling vigour and yield of mixed forages were very poor, whereas they were remarkedly enhanced by the treatments of $T_2$ and $T_3$. Comparing with the $T_2$ treatment the forage yields were increased 3.1% in orchardgrass, 27.5% in ladino clover, and 12.8% in mixed forages by the application of kieserite($T_3$). In the grass-clover mixed swards, the application of kieserite more remarkedly influenced the seedling vigour, botanical composition, and yield of clover than those of grass.

• The Korean Journal of Ecology
• /
• v.17 no.1
• /
• pp.23-35
• /
• 1994

To investigate phytotoxic substances in Artemisia argyi, the donor plant, and their biological activities, seed germination and seedling growth of receptor plants such as Arundinella hirta, Echinochloa crus-galli, Rumex crispus and Lactuca sativa were examined at different concentrations of aqueous extracts of the donor plant. Germination of four receptor species was inhibited by the extracts, while seedling growth was decreased to a lesser degree than in the germintion test. Germination, seedling growth and dry weight growth of Achyranthes japonica grown in pot were proportionally inhibited by the extracts. Volatile substances emitted from A, argi plant caused slight inhibition in the germination and seedling growth of the receptor species. Essential oil of the plant extracted by Karlsruker's apparatus inhibited growth of microorganisms and callus growth of Pinellia ternata and Oryza sativa. The GC /MS method was employed for analysis and identification of allelochemicals from A. argyi leaves. Sixty-one chemical substances such as a-pinene, camphene, 1. 8-cineol, etc. were identified from essential oil of A. argyi. The results of this experiment on seed germination, seedling growth, microorganism culture and tissue culture indicated that naturally occurring chemical substances from A. argyi would be responsible for the growth inhibition of plants studied.

• Journal of Plant Biology
• /
• v.30 no.1
• /
• pp.59-67
• /
• 1987

To verify allelopathic effect of tomato plants a number of labovatory experiments, seed germination and seedling growth with aqueous extracts and leachates form the tomato plants, have performed. Germination percentage of the tested species was decreased by treatment with leaf, stem and root extracts as extracting time elapses. The leaf extract more inhibits the germination of the seeds than both stem and root extracts. Leachate collected from the tomato plants decreases as much as 50% of the growths in elongation as well as dry weight of seedlings of lettuce and egg plant. It is observed that with a paired-plants grown in U tube pot the tomato roots have excreted allelochemicals to inhibit the growth of the tested species and volatile substances from the tomato plants have suppressed to dry weights of lettuce, to elongation and dry weights of grapevine planted near the tomato plants.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.1
• /
• pp.68-74
• /
• 1994

A bacterial strain YB-70 which has powerful biocontrol activity against Fusarium solani causing plant root-rot resulting in considerable losses of many economical crops was isolated and selected from over 500 isolates from a ginseng rhizosphere in suppressive soil, and identified as a strain of Bacillus subtilis. In several biochemical and in vitro antibiosis tests on F. solani with culture filterates from B. subtilis YB-70, our data strongly indicated metabolites which mediated inhibition of the fungal growth were presumed to be heat-stable, micromolecular, and ethyl alcohol solutable antifungal substances. Suppression of root-rot by B. subtilis YB-70 was demonstrated in pot trials with eggplant (Solanum melongena L) seedlings. Treatment of the seedling with the bacterial suspension (1.7~1.9$\times$$10^5$ CFU/g) in F. solani-infested soil significantly reduced disease incidences by 68 to 76% after 25 to 30 days. The results supported that B. subtilis YB-70 have excellent potentials as a biocontrol agent.

• Korean Journal of Plant Resources
• /
• v.9 no.2
• /
• pp.157-163
• /
• 1996

This study was carried out to control the decrease of yield and the deterioration of quality of Angelica gigas roots by bolting. This phenomenon resulted from lignificartion and dwarfishness of roots because of bolting formed for inflorescence and fruition. Seedlings were grown for 60,90 and 120 days in nursery of the green house, and transplanted in main field to compare with traditional seedling that grew for 1 year. Growth of the petiole length compare with length and leaf width of aerial parts in nursery showed a remarkably progress, and root characters as root length, root diameter and root weight grew more vigorously in the order of nursery periods. Bolting was not entirely formed in plots transplanted the seedlings which grown for short-time; 60, 90 and 120days, but showed the high bolting rate, 64.3%,in traditional seedling plots. Yield was higher in plots that transplanted short-time growing seedlings than that transplanted traditional seedlings, and among 3 kinds of nursery periods yields were high in the order of nursery periods. For the increase of yield and decrease of bolting rate, it was needed to transplant small seedlings of 3-4g/plant which grew in nursery for 90-120 days.

• Journal of Bio-Environment Control
• /
• v.29 no.4
• /
• pp.365-372
• /
• 2020

This study was conducted to compare the effects of foliar spray and sub-irrigation of the triazole fungicide diniconazole on the regulation of stem elongation and to investigate the stimulation of root system development during the seedling stage. Comparing the two application approaches, there were significant differences in the leaf area, leaf area ratio (LAR), plant height, compactness, fresh shoot and root production, relative growth rate (RGR), and root to shoot ratio (R/S). At the same application concentration, the sub-irrigation showed a better retarding effect on growth than the foliar spray, because the PGR activity of diniconazole in root absorption was higher than that in shoot absorption. For reaching a target of 20% to 30% inhibition rate of stem length, foliar application concentration of diniconazole exceeded 10, however, only approximately 1 was required in the sub-irrigation application. The root system of tomato seedlings responded strongly to diniconazole application. Total root length, root volume, root average diameter, and the number of root tips increased when diniconazole was sub-irrigation application at 1. A reduction in fine roots (diameter range of 0 to 0.3 mm) and an increase in the roots with a diameter range of 0.3 to 0.6 mm was observed, and this may contribute to the increase in average diameter. The increase in root average diameter may be positive because root penetration increases with root diameter. Our results suggested that sub-irrigation maximized the PGR activity of diniconazole to enhance the retarding effect. And it also possible to enhance the tomato seedling root system by diniconazole stimulating with a lower concentration.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.2
• /
• pp.189-195
• /
• 1997

To cope with increasing importance of water stress in food crop production, characteristics and cultivar differences in physiological responses of winter barley plants to water stress during seedling stage were studied employing three covered-barley, Milyang 12, Durubori, and Olbori, one naked-barley, Baekdong, and one two-row beer-barley, Hyangmaeg. Water stress was given to barley plants by withholding watering in soil-culture pots or by adding P.E.G. (polyethylene glycol, M. W. 4,000) to the nutrient culture solution. When water stress was imposed by withholding watering for 10 days to the seedlings grown in pot-soil for 10 days after emergence, leaf water potential of 5 cultivars was decreased almost to the same degree, from control -3.5 bar to the water stressed -26.6 bar. However, growth and some physiological responses were differently affected by cultivars: The plant height was decreased by 16-26％ : seedling dry weight by 25∼42％ ; chlorophyll content by 21∼39％ ; second leaf survival rate by 8∼18％ ; and free proline content per gram of leaf dry weight was increased from control 0.2∼0.5mg to the water stressed 5.8∼13.2mg. Drought resistances of 5 barley cultivars, based on the leaf survival rate and the decreased rate in seedling dry weight at the end of stress treatment, were high in the order of 3 covered-barley＞naked-barley＞two-row barley.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.6
• /
• pp.483-488
• /
• 1993

This study was conducted to obtain the basic information for easily judgement to level of salinity stress of the reclaimed land. Rice varieties used were Nakdongbyeo and Chilsungbyeo. In seedling stage, 13 day-old seedlings were subjected to salt solution (0, 30, 60, 90mM) for 8 days. In reproductive stage, 30 day-old seedlings were transplanted 3 hills(3 seedlings /hill) per plastic pot (diameter 28${\times}$depth 30cm). Salinity stress was given by immersing pot in the salt solution(sea water) with 4 concentrations(0, 30, 60, 90mM)for 8 days at booting stage. The stomatal resistance was increased with salinity concentrations. Salinity stress appeared to be more sensitive in seedling stage than in reproductive stage in each concentrations. The photosynthesis was decreased in salinity treatment. Salt-treated periods influenced unfavorably stomatal resistance in each stages. The leaf chlorophyll content was remarkably decreased by increasing salt concentrations. The absorption of Na+ and Cl￣ were increased as salt concentration in the culturing medium became higher, but there was no appearent difference in the absorption of K+, Mg++, and Ca++. The plant height and root length were decreased in salinity treatment. The inhibitory effect of salinity stress on root growth was more severe than in shoot growth. The stomatal resistance could have been used as bio-information.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.7 no.1
• /
• pp.25-30
• /
• 1987

There are differences in opinion as to whether nitrogen fertilizer should be used when establishing alfalfa (Medicago sativa L.). Various reports show that under a hot environment, rhizobia (Rhizobium meliloti) are not as effective in fixing atmospheric nitrogen as they are under moderate temperatures. It is also believed that the addition of nitrogen fertilizer inhibits nodulation of alfalfa seedlings. A replicated experiment was conducted under controlled environmental conditions at the University of Nevada-Reno, Reno, Nevada, USA, to determine the effects of nitrogen application on seedling growth and nodulation of alfalfa grown in a hot environment. Sterile sand was used as the growing media to which a complete nutrient solution minus nitrogen was applied volumetrically to each pot daily. In addition, half of the pots received NH4-$NO_3$, at the rate of 11.2 kg per ha at seeding and at two and four weeks after planting giving a total nitrogen application rate of 33.6 kg per ha during the seven-week experimental period. Rhizobia inoculant (R-12) consisted of a mixture of strains 171-15a, 1682c and 80 PI 265 of (Rhizobium meliloti). Inoculant was applied to the seeds prior to planting and to the sand media at two and four weeks after seeding. Twenty seeds were planted in pots 14.0 cm in diameter and 11.5 cm deep. Plants were thinned to ten plants per pot after emergence and were grown in a controlled environment chamber with a 16-hour light period. Soil temperature at 6 cm depth ranged from 17.4^{\circ}C.$ to 31.1^{\circ}C.$ and had a daily mean of 26.5^{\circ}C.$. Plants were harvested at weekly intervals for seven weeks. Root, shoot and total length, dry weight, volume and number of nodules per plant were determined. Root, shoot, and total length were greater in seedlings grown in soil where nigrogen was applied than that grown in soil to which no nitrogen was applied. The average size of the seedlings as determined by volume and weight was more than two times greater where plants were fertilized with nitrogen. Nodule number per seedling was also greater when nitrogen was applied compared to those which received no nitrogen. The differences were greater as the plants became older. The rhizobia did not fix enough nitrogen for adequate growth of seedlings. This is probably due to high temperature growing conditions that caused the rhizobia to become relatively ineffective as compared to cooler growing conditions. Data suggests it would be desirable to apply nitrogen at seeding when alfalfa is established under hot conditions that occur in mid- or late summer.