• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.2
• /
• pp.63-70
• /
• 2012

Larix kaempferi and Betula costata seedlings were grown under an elevated temperature ($27^{\circ}C$) for four weeks to understand initial changes on physiological characteristics caused by temperature rising in connection with global warming. At the end of the treatment, growth performance, leaf pigment content, antioxidative enzyme activities and malondialdehyde (MDA) content were measured and analyzed. Relative growth rates of the height of two tree species grown under elevated temperature ($27^{\circ}C$) were lower than those of control ($24^{\circ}C$) and dry weights of leaves, stems and roots were also reduced at higher temperature. Particularly, the root growth reduction of two tree species increased markedly at $27^{\circ}C$ over the study period, which increased the ratio of shoot to root. Under higher temperature, leaf pigment contents decreased, whereas anti-oxidative enzyme activities such as ascorbate peroxidase (APX) and catalase (CAT) increased as compared with the control. But MDA content was not affected by elevated temperature. In conclusion, the elevated temperature leads to root growth reduction, restriction of nutrient uptake from soil and the reduction of leaf pigment contents, which can inhibit the aboveground growth. In addition, higher temperature might act as a stress factor that causes growth reduction through the increase of energy consumption during a growth period.

• Korean Journal of Soil Science and Fertilizer
• /
• v.38 no.4
• /
• pp.218-221
• /
• 2005

The present study was investigated in the Chittagong hill forest of Bangladesh to assess the feasibility of ginger cultivation under multipurpose forest and fruit tree species. There were three treatments such as i) ginger grown under open field condition, ie. full sunlight (T1), ii) ginger grown under Gamar tree (spacing of $90{\times}90cm$ (T2) and iii) ginger grown under guava tree (spacing $180{\times}180cm$) tree (T3). The experiment was laid out in randomized block design (RBD) and each treatment was replicated three times. From data it was observed that some morphological parameters of ginger such as plant height, number of leaves per plant, leaf length and leaf breadth were higher in the treatments T2 and T3 as compared to the treatment T1. A positive and linear relationship was observed between the weight of rhizome and yield of ginger which caused the highest yield of ginger ($23.63Mg\;ha^{-1}$) under guava tree species at partial shaded condition in the T3 treatment ($180{\times}180cm$), whereas the lowest yield ($15.64Mg\;ha^{-1}$) was recorded in the T2 treatment when ginger was cultivated under Gamar tree species at closer spacing ($90{\times}90cm$). Therefore, it was revealed that partial shaded condition favoured the optimum growth and yield of ginger, whereas the dense shade from intensively planted tree species badly affected the dry matter production and yield of ginger.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.4
• /
• pp.591-596
• /
• 2011

The applications of chemical fertilizers and various types of organic materials may cause heavy metal accumulation in soil. In this study, we conducted to investigate the relationship between the different chemical forms of heavy metals such as Cr, Cd, Pb, Cu, Ni, and Zn retained in soil and the metal concentrations in Korean raspberry plant. Forty five soil samples were collected from 2 to 6 years old Korean raspberry cultivation fields (RCFs), Gochang, Korea, to determine total, exchangeable (1.0 M $MgCl_2$-extractable), DTPA-extractable metal contents. The leaves and fruits of raspberry plant were sampled at harvest stage. Total metal contents in soils ranged from $0.87mg\;kg^{-1}$ to $66.82mg\;kg^{-1}$. Exchangeable and DTPA-extractable metals ranged between 0.02 and $0.67mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $7.07mg\;kg^{-1}$, respectively. The metal concentrations in the plant leaf and fruit determined on a dry-basis were between $1.30mg\;kg^{-1}$ and $38.82mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $21.51mg\;kg^{-1}$, respectively, but Cd and Pb were not detected in the leaf. The total, exchangeable, and DTPA-extractable contents of the metal ions in soil were directly correlated one another, but the contents of different metals in the different fractions were inversely correlated in general. Most of total and DTPA-extractable metals in the soil were directly correlated with the contents of the same metals in the plant, whereas exchangeable metals in the soil were not statistically correlated with the same metals in plants. Thus, we concluded that the metal contents in the raspberry field soils were much lower thanthe levels of Soil Contamination Warning Standard (SCWS), and the plant metal concentrations were also less than the maximum permissible limits. The total and DTPA-extractable metals in the soil were closely related to the metal concentrations in the plant.

• Research in Plant Disease
• /
• v.12 no.2
• /
• pp.69-74
• /
• 2006

Basal rot of freesia caused by a Sclerotium sp. occurred at Incheon areas. Incidence of the disease reached up to 45% and averaged 17.0% in the fields. Typical symptoms consisted of sheath dry and leaf blight due to rots on basal leaves. The causal fungus was identified as Sclerotium sp. based on following mycological characteristics. The fungus formed sclerotia on cultural media and plant tissues, but did not produce asexual spores. On cultural medium, aerial mycelia of the fungus changed color from white to clay with cultural age and smelled musty odor. Numerous irregular and elliptical black microsclerotia of the fungus were formed on potato dextrose agar (PDA) after 5 days of incubation at $25^{\circ}C$ and sized $115{\sim}200{\times}95{\sim}150 (av. 145{\sim}126.5){\mu}m$. The fungus grew at $10{\sim}32^{\circ}C$ and $pH 4.0{\sim}8.5$. However, the optimal temperature and pH for mycelial growth of the fungus were $24^{\circ}C$ and 5.5 respectively. The isolate showed present pathogenicity to not only freesia but gladiolus in the pathogenicity test, and the symptoms were similar to those observed in the fields. Basal rot of freesia caused by Sclerotium sp. is firstly reported in Korea.

• Korean Journal of Organic Agriculture
• /
• v.10 no.2
• /
• pp.111-120
• /
• 2002

This study was conducted to investigate the effect of foliar application of Chitosan and seedling types on increasing the production of fall-growing potatoes(Solanum tuberosum) at the height of 250m from the sea in Jeju Island. The experiment main-plots consisted of four Chitosan applications, and subplots had three seedling types as cutting plug seedlings, mine-tuber plug seedling planting plot and seed potatoes planting plot. The foliar application of Chitosan of 2000ppm was carried out 0, 1, 3, 5 times at intervals of ten days after ten days of transplanting. Plant height and top dry weight were significantly more vigorous as three to five application of Chitosan. In the small tubers(under 80g), the number of tubers and tuber yield were relatively increased in the seed potatoes planting plot and mine-tuber plug seedling plot, but the large tubers(over 80g) was higher in the cutting plug seedling planting plot. T-N content in leaves was increased as the number of application of Chitosan was increased. A similar tendency was shown in K, P Ca, Mg and Na. The growth and tuber yield in cutting plug seedlings, mine-tuber plug seedling planting plot and seed potatoes planting plot were effectively increased as three to five foliar applications of Chitosan was increased.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.23 no.3
• /
• pp.143-150
• /
• 2003

This study was conducted to determine the response of main growth characters, yield and chemical composition of Jeju native soybean based on the difference between phosphate rates (0, 50, 100, 150, 200, 250kg/ha) from May 11 to September 10 in 2002 in Jeju island. Days to flowering was delayed from 92 days to 97 days as the increasing of phosphate rate. Also plant height grew longer from 109cm to 124cm. The number of branches and leaves, stem diameter, root length and weight of root grew powerful as phosphate rate increased from 0 to 250kg/ha. Fresh forage yield was 26.5MT/ha in the nonphosphate plot and then was 36.9MT/ha as phosphate rate increased to 250kg/ha. And the difference between 200kg/ha and 250kg/ha in phosphate rate was not significant. Dry matter, crude protein and TDN yield increased 6.0∼7.9MT/ha, 0.9∼1.4MT/ha and 3.4∼4.9MT/ha respectively, as the increasing of phosphate rate. Also crude protein, crude fat, NFE and TDN content increased 15.5∼18.3%, 2.2∼3.3%, 42.5∼43.5%, and 56.7∼61.9% respectively. In contrast with this, crude fiber and crude ash decreased 32.1∼28.1% and 7.7∼6.8% respectively. To reach the climax of forage yield was estimated optimum phosphate rate to be 200kg/ha.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.23 no.4
• /
• pp.299-306
• /
• 2003

This study was carried out to select superior soybean cultivars for forage production for soybean forage production in Jeju. The results obtained are summarized as follows; Eighteen soybean cultivars were grown from May 11 to September 11 in 2002 in Jeju to select superior cultivars for forage production. Days to flowering was shortest(58 days) for Seokryangkong and Keunolkong, and longest(93 days) for Danpaheukdu. Days to flowering for other cultivars ranged from 65 to 69 days. Pureunkong and Namhaekong had greater heights(129.3 and 124.6 cm, respectively) while Keunolkong, Hwaeomkong and Seokryangkong had shorter heights. The number of branches per plant was gratest for Sobaekkong, Manrikong, Pungsankong, Kwangankong and Geumgangkong. The number of leaves per plant was geatest for Sobaekkong, Iksankong and Namhaekong. Rueunkong and Jangmikong had thicker stems. Fresh forage yield was greatest for Iksankong, Sobaekkong and Namhaekong(39.5, 39.3 md 38.0 MT/ha respectively). DM yield of forage was featest for Baekunkong, Hnrunkong and Danpaheukdu. Danwonkong, Dawonkong, Seokryanfong and Pungsankong had ueatest forage crude protein content. Duyukong and Kwangankong had featest forage crude fiber content. Jangmikong and Keunolkong had feater crude fat content, while Sobaekkong and Kwangankong had greater crude ash content. Namhaekong, Seokryangkong, Keunolkong and Jinpumkong had greater NFE contents ranging 40.0 to 43.5 and TDN was featest in Keunolkong, Danpaheukdu, Namhaekong and Seokryangkong had greater NFE contents ranging from 59.8 to 60.9％. The best cultivars in Jeju for forage soybean appear to be Namhaekong, Danpaheukdu md Baehukong on the basis of crude protein, TDN, and dry matter yields.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.23 no.4
• /
• pp.271-276
• /
• 2003

A Jeju local variety of Italian millet (Setaria italica Beauvois) was grown at five seeding rates (6, 9, 12, 15 and 15 kg/ha) from May 1 to August 25, 2003 at Jeju to determine influence of seeding rate on agronomic characters, forage yield and quality. Days to flowering increased from 89 to 96 days as seeding rate increased from 6 to 18 kg/ha. The plant height increased from 128 to 148cm as seeding rate was increased from 6 to 12 kg/ha and then decreased to 131cm at a rate of 18 kg/ha. With increasing seeding rate, stem diameter, number of leaves, number of nodes, leaf width and weight per plant decreased but leaf length had the same trend with plant height. As seeding rate increased from 6 to 12 kg/ha, fresh furage, dry matter, crude protein, and total digestible nutrients (TDN) yield increased from 35.93 to 54.83 MT/ha, 10.49 to 17.43 MT/ha, 0.94 to 1.79 MT/ha and 5.33 to 9.27 MT/ha, respectively, and then decreased with further increased seeding rates. Crude protein, either extract, nitrogen free extract, and TDN content increased 9.0 to 12.01％, 1.3 to 1.8%, 45.6 to 47.8% and 50.8 to 55.0%, respectively, but crude fiber content decreased 35.2 to 30.0% and crude ash declined 5.8 to 8.4% as seeding rate increased from f to 18 kg/ha. The optimum seeding rate to obtain the highest forage yield was estimated to be 12 kg/ha.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.23 no.4
• /
• pp.265-270
• /
• 2003

This study was conducted to determine the influence of seeding date on growth, characteristic yield and chemical composition of Italian millet (Setaria italica) from April 20 to May 30, 2003(April 20, May 1, May 20 and May 30) in Jeju. A local variety was seeded on days to heading were lessened as seeding date was delayed. The plant height was longest when seeded on 1 May(131cm) than at the other seeding dates. Stem diameter, number of leaves, leaf length and leaf width had the similar trend with plant height. SPDA reading values were greater at earlier seedings. Fresh forage yield was greatest (43.28MT/ha) at 1 May seeding and decreased gradually before or after this seeding date. Dry matter yield, crude protein yield and total digestible nutrient (TDN) yield had nearly the same tendency with fresh forage yield. Crude protein, crude fat, NFE and TDN contents were greatest at 30 May seeding and then decreased earlier seedings. Crude ash and crude fiber content tended to decreased as seeding was delayed. Based on the these findings, optimum seeding date for forage production of Italian millet seems to be early May in Jeju island.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.23 no.3
• /
• pp.135-142
• /
• 2003

Jeju native soybean was grown at five plant densities(30${\times}$30cm, 30${\times}$25cm, 30${\times}$20cm, 30${\times}$15cm, 30${\times}$10cm) from May 11 to September 10 in 2002 in Jeju island to determine the optimum plant density. Days to flowering was delayed from 94 days to 98 days as increasing of plant density. Plant height was 103cm at 30${\times}$30cm plot, as plant density increased, was 117cm at 30${\times}$10cm plot. As plant density increased, the number of branches and leaves, stem diameter, weight of plant, root length and weight of root grew low. As plant density increased from 30${\times}$30cm to 30${\times}$15cm, fresh forage, dry matter, crude protein and TDN yield increased 23.3∼36.5MT/ha, 5.1∼8.0MT/ha, 0.8∼1.4MT/ha and 2.9∼4.8MT/ha respectively, but decreased at 30${\times}$10cm plot. As plant density increased, crude protein, crude fat, NFE and TDN content increased 16.2∼17.9%, 2.7∼3.7%, 37.6∼40.7% and 56.1∼60.0% respectively. In contrast with this, crude fiber and crude ash decreased 34.9 ∼30.8% and 8.6∼7.2% respectively. To reach the climax of forage yield was estimated optimum plant density to be 30${\times}$15cm.