• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.2
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• pp.2634-2648
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• 1972

The aim of this Study is to bring Light on the effect of irrigation water temperature to the growth and harvest of Paddy rice in Various water Sources. 1. This research was completed in the writer's home nursery garden Located in Chungyoung-Ri, Hoeng sung-Myun, Hoengusung-Konn, Kangwan-Do. 2. The variety of Paddy rice was the IR667. 3. Practice was done by the treatment I .e river water, reservoir, tube well cold and tuke well warm with 3 riplications each. 4. The Paddy was transplanted in a pot 0.9 meter height and 1 meter Square without hottom filled with paddy soil to a planting depth 0.5 meter. The pot was laid underground and Covered with a film of polyethylene to keep of the rain. 5. The method of Cultivation was that used by the Filed Crops Experiment Station of the Office of Rural Development. 6. Atmospheric temperature was recorded every day of the growing period. The precipitation and Sun light was quoted by the KF-46 of Hoengsung. 7. The Soils in the test plots was relatively fortile, being Similar to ordinary paddy soils. 8. The charactor of irrigation water of surface and underground was both normal. 9. During the period of growth the average temperature of the underground water as $14.2^{\circ}C$ and that of the Surface was $24.1^{\circ}$. 10. The most useful water for the rice growing was that of river and reservoir while underground water was found to be generally injurious to the paddy growth because of low temperature. 11. In the case of underground water, there proved to be such harmful effects as reduction of culm length, rate of mature grain, panicle Length and grain weight and delay of tillering time, and heading time. Reading Therefore the writer conduded that the harvest of rice irrigated with underground water Showed a reduction of 15.8% compered with the rice irrigated by surface water.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.1-8
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• 1995

This study was carried out to investigate the effects of floral inhibition of An-gelica gigas NAKAI in the hilly altitude located in the Northern Gyeongbuk Province from Feb. 1992 to Nov. 1994. The results obtained were as follows ： As the cultivated areas are high, rate of bolting was significantly decreased, having high yield, good growth, and medicinal quality. It is considered that the optimal cultivating area was at least above 600m altitude. In the hilly altitude, the more shorten nursery period was, the more decreased rate of bolting was, it results in decreased yield, having no significant differences in contents such as extracts and decursin. In bolting response from temperature treatment of the seedlings, treatment of high temperature was significantly decreased floral induction, but rate of establishment was decreased by decayed root. Bolting rate at different organic resources has more reduced in single fertilization than that of in organic application, but among organic resources, compost of rice straw has the lowest bolting rate. As a result, yield and medicinal qualities at various organic resources were increased in application of organic resources which was no con-siderable tendency among organic resources.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.371-384
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• 1982

Highly cold tolerant varieties are requested not only at high latitute cool area but also tropical high elevated areas, and the required tolerance is different from location to location. IRRI identified 6 different types of cold tolerance required in the world for breeding purpose; a) Hokkaido type, b) Suweon type, c) Taipei 1st season type, d) Taipei 2nd season type, e) Tropical alpine type and, f) Bangladesh type. The cold tolerance requested in Korea is more eargent in Tongil group cultivars and their required tolerance is the one such as the physiological activities at low temperature are as active as in Japonica group cultivars at least during young seedling stage and reproduction stage. With conventional Japonica cultivars, such cold tolerant characters are requested as short growth duration but stable basic vegetative growth, less sensitive to high temperature and less prolonged growth duration at low temperature. The methods screening for cold tolerance were developed rapidly after the Tongil cultivar was reliesed. The facilities of screening for cold tolerance, such as, low temperature incubator, cold water tank, growth cabinet, phytotron, cold water nursery in Chuncheon, breeding nursery located in Jinbu, Unbong and Youngduk, are well established. Foreign facilities such as, cold water tank with the rapid generation advancement facilities, cold nurseries located in Banaue, Kathmandu and Kashimir may be available for the screening of some limitted breeding materials. For the reference, screening methods applied at different growth stages in Japan are introduced. The component characters of cold tolerance are not well identified, but the varietal differences in a) germinability, b) young seedling growth, c) rooting, d) tillering, e) discolation, f) nutrition uptake, g) photosynthesis rate, h) delay in heading, i) pollen sterility, and j) grain fertility at low temperature are reported to be distinguishable. Relationships among those traits are not consistent. Reported studies on the inheritance of cold tolerance are summarized. Four or more genes are controlling low temperature germinability, one or several genes are controlling seedling tolerance, and four or more genes are responsible for the pollen fertility of the rice treated with cold air or grown in the cold water nursery. But most of those data indicate that the results may come out in different way if those were tested at different temperature. Many cold tolerant parents among Japonicas, Indicas and Javanicas were identified as the results of the improvement of cold tolerance screening techniques and IRTP efforts and they are ready to be utilized. Considering a) diversification of germ plasm, b) integration of resistances to diseases and insects, c) identification of adaptability of recommending cultivars and, d) systematic control of recommending cultivars, breeding strategies for short term and long term are suggested. For short term, efforts will be concentrated mainly to the conventional cultivar group. Domestic cultivars will be used as foundation stock and ecologically different foreign introductions such as from Hokkaido, China or from Taiwan, will be used as cross parents for the adjustment of growth durations and synthsize the prototype of tolerances. While at the other side, extreme early waxy Japonicas will be crossed with the Indica parents which are identified for their resistances to the diseases and insects. Through the back corsses to waxy Japonicas, those Indica resistances will be transfered to the Japonicas and these will be utilized to the crosses for the improvement of resistances of prototype. For the long term, efforts will be payed to synthsize all the available tolerances identified any from Japonicas, Indicas and Javanicas to diversify the germ plasm. The tolerant cultivars newly synthsized, should be stable and affected minimum. to the low temperature at all the growing stages. The resistances to the diseases and insects should be integrated also. The rapid generation advancement, pollen culture and international cooperations were emphasized to maximize the breeding efficiency.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.429-438
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• 2007

Early growth vigor(EGV) is one of the physiological characteristics that may contribute to the increase of genetic yield potential and radiation use efficiency by closing the canopy earlier. To estimate the genotypic variation of EGV, determine the relationships among the related traits, and identify the rapidly growing genotypes and indirect indicator for selection in breeding program, the evaluation of EGV and EGV-related traits was conducted for a total of 140 rice varieties consisting of 101 Korean, 25 Northern China and 14 IRRI-bred rice varieties in a serial sowing experiment in plastic rain shelter and plastic-covered nursery bed in 2003. EGV defined as the amount of leaf area and/or dry weight produced early in the season and the EGV-related traits such as length and breadth of the $2^{nd}\;and\;3^{rd}$ leaves showed highly significant positive correlation with the embryo and seed weight. Especially, the genotypic variation in the length of the third leaf was explained over 90% of genotypic variation in the seed weight. Owing to a large effect of seed size on EGV and its related traits, vigor measurements were adjusted based on their linear or exponential relationships with seed weight for excluding the seed weight effect. EGV and its related-traits adjusted for seed weight also showed big variation among genotypes. Increased EGV was genetically correlated with increases in breadth and length of early leaves. The broad-sense heritability for EGV was significantly high(81%), but lower than those of leaf breadth(90% for the $2^{nd}$ leaf and 93% for the $3^{rd}$ leaf) and length(87% for the $2^{nd}$ leaf and 89% for the $3^{rd}$ leaf). Significantly positive genetic correlations were found between EGV and the breadth and length of early leaves. The high heritability of early leaf breadth and length coupled with their strong genetic correlation with EGV indicated that the breadth and length of the $2^{nd}\;and\;3^{rd}$ leaf would be used as good indirect indicators for EGV selection in rice breeding program.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.17-26
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• 1979

Comparative tolerance of the new rice varieties from Indicax Japonica cross to elastic and plastic chilling injuries was examined at the 3rd leaf-stage, the most sensitive stage to chilling during nursery, using a chilling chamber set 11\circ C, 13hrs. 20K lux day/5$^{\circ}C$ night. Seedlings were reared until 35 days after seeding in a 26\circ C, 13hrs. day / 18\circ C night chamber except the period of chilling treatment for 0, 3, 4, 6, 8 or 10 days. The new varieties were approximately twice susceptible to elastic injuries, and thrice susceptible to plastic injuries than the Japonica varieties in the term of chilling duration. Among the variables indicating apparant chilling injuries the reduction in dry matter responded most sensitively and differentiated well the varietal difference in chilling resistance even with shorter chilling period. Sequential aspects of the cause and effect relations involved in the development of the apparant chilling injuries are discussed and a schematic diagram is presented as Fig. 5 in the text.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.636-642
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• 2006

To make a new fairy ring of Tricholoma matsutake in situ, the way of production and transplanting of ectomycorrhizal seedlings of T. matsutake using Pinus densiflora was investigated after transplanting from 2000 to 2005 as well as the method to improve their survival rate for the fungus. For the production of ectomycorrhizal pine seedlings, the seedlings planted at the edge of fairy ring of T. matsutake in November showed 97% of the survival rate, while those planted in April showed 80% of the rate. For the complete infection of the T. matsutake, it required more than two years after planting. The infection rate of mycelia for the ectomycorrhizal seedlings was 17.6% when the natural seedlings were used, whereas it was relatively low when the seedlings prepared from the nursery were used. The survival of T. matsutake mycelium reached up to 22% by the transplanting in April, while the mycelium transplanted in October and November showed less than 5% of the survival. The survival of T. matsutake on the transplanted seedlings was the highest in the seedlings having 50% of infection rate before transplanting. Excavation of the ectomycorrhizal seedling to examine the vitality of ectomycorrhizal roots of T. matsutake resulted in the perishing of them. Therefore, the method using a 'rice bag triers' to check living mycelium of T. matsutake without digging of transplanted seedlings was introduced in this study. In addition, it is recommended that the examination has to be conducted at least two years after transplanting.

• The Korean Journal of Mycology
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• v.11 no.4
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• pp.169-175
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• 1983

For the classification of 531 isolates of Fusarium moniliforme from infected rice plants, five criteria were employed for clarifying the mycological difference from I to IV based on host symptoms, conidial formation, septate of macroconidia, color of mycelium on the culture, and fungicide response. Four strains I, II, III, and IV were detected and Strain IV was the most prevalent one. Based on mycological characteristics, macroconidia with 6 or 7 septate were mostly produced by Strains I and II. Four septate macroconidia were mostly formed by Strain III while Strain IV mostly formed 3 septate macroconidia. Strain I was reddish purple (5RP 5/4) on both the bottom and the surface of the media. Strain II produced reddish purple(5RP 3/2) on both the bottom and the surface of the media. Strain I produced mostly macroconidia in pionnotes on the media surface while Strain II produced mostly microconidia in pionnotes on the media surface. Both of Strain III and IV produced mostly macroconidia in sporodochia on the surface of the mycelium. Strain IV was less reduction of germination and caused abnormal elongation of all parts of the plants, but did not kill the plants in nursery boxes. Strain III killed fewer plants than Strain IV. As above results, isolates of F. moniliforme were classified into four strains I, II, III, and IV, on the basis of five criteria.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.137-145
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• 1981

Using the milled, blast infected leaves (BIL) as an inoculum source on the screening for the resistance to blast of rice plant was a simple and useful technique. The temperature with high (25^\circ C\sim 35^\circ C) and low (15^\circ C\sim 28^\circ C) and the water stressed or not, was conditioned of to the inoculation with the BIL to the test varieties in seedling stage. In low temperature, most of the varieties were more infected with blast, however the Indica-Japonica hybrids were more infected in high temperature conditions. The water stressed was more infected with blast than the not stressed. The interaction of variety with water stress was not so much as that of variety with temperature. Resistant reaction to blast (BIL) was not affected by the temperature and water stress, but the moderately resistant or susceptible one was much affected by them. Inoculum of BIL was virulent to the newly bred Indica-Japonica hybrid cultivars such as Tongil, Nopung, etc, but not virulent to the Japonica cultivars such as Nongbaek, Jinheung, etc. The discrete, mixed or variable lesions were observed mainly in the moderately resistant or susceptible cultivars such as Kanto 51, Yashiromochi, Ishikari-shiroke, etc.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.5 no.1
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• pp.37-43
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• 1969

A genetrc study was made on plant height of indica rices with a few segregating F2 populations involving three semi-dwarf varieties such as T(N)I, CP231-SLO17, and B569A12. These populations were grown in breeding nursery at the International Rice Research Institute (IRRI) during several seasons. 20 to 25 day old seedlings grown at upland seedbed were transplanted to the paddy in a single plant hill spacing 30 cm ${\times}$ 25cm. Measurements of plant height were made from the juncture between culm and roots to the tip of the longest panicle of a plant pulled out from the paddy when they are matured. The results are summarized as follows: 1. Tall indica varieties originated from the south-east Asian countries could be classified into two groups depending upon their allelism whether they showed monogenic segregating ratio of 3:1 or not when they were crossed to T(N)1. 2. Most of U.S. varieties, especially semi-dwarf breedirg materials such as CP231 ${\times}$ SIO17 and B569A12, did not show monogenic segregating mode of 3:1 ratio when they were crossed to T(N)1 or to other varieties bearing the same genetic allele of T(N)1 such as Peta and Sigadis.

• Research in Plant Disease
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• v.22 no.4
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• pp.264-268
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• 2016

The nursery test against rice blast in Korea from 2014 to 2015 was analyzed. The average of disease severity of leaf blast in 12 sites showed $3.7{\pm}2.1$ in 2014 and $4.4{\pm}2.1$ in 2015. Disease severity of leaf blast in Icheon and Cheolwon was increased ranging from $2.8{\pm}2.2$ in 2014 to $6.3{\pm}1.8$ in 2015. Using a designation system, a total of 588 isolates collected those years were categorized into 34 races in 2014 and 51 races in 2015 based on the reaction pattern of Korean differential varieties. The blast isolates of 2015 were more diverse than those in 2014. The ratios of KI race to KJ race were 54:46 in 2014 and 70:30 in 2015; however, the predominant race population was KJ-301 as 16%, and KI-101 as 15% in 2014 and 2015, respectively. These results indicate that the distribution of the blast races is getting more diverse in Korea, therefore, this research would provide the possibility to predict race distribution and change to prevent the outbreak of rice blast and will also serve as a useful information for breeding of resistant rice cultivar against blast.