• Korean journal of applied entomology
• /
• v.34 no.4
• /
• pp.360-367
• /
• 1995

The relative toxicity of abamectin was assessed to the predatory mite Amblyseius womersleyi Schicha and to dicofol-resistant and -susceptible twospotted spider mite (TSM) Tetranychus urticae Koch in the laboratory. Abamectin was much les toxic to the predator than to the spider mite. At 0.12 and 0.6 ppm, all TSM adult females of the tow strains were killed within 48 h after dipping n the solutions. The lower concentrations (0.06 and 0.012 ppm) killed more than 77% of TSM female adults of the two strains at 120 h after treatment. However, abmectin did not significantly affect the survival and mobility of A. womersleyi female adults at a concentration of 0.12 ppm but the mortality was slightly increased up to 20~23% at 0.6 and 6 ppm. Abamectin did not significantly affect hatchability of one-day old TSM eggs at 0.06~0.6 ppm. The Four-day old eggs were much more susceptible to abamectin than one-day old eggs were. Within 0.006-6 ppm, abamectin did not affect the hatchability of A. womersleyi eggs and the development of resulting immature predators. When the predator female adults were dipped in 0.6 and 0.12 ppm solution, their reproduction was not affected, but at 6 ppm it was decreased by 35%. However, the reproduction of TSM reduced significantly at concentrations between 0.006 and 0.6 ppm. The differential toxicity of abamectin between TSM and the predator could be of practical importance in managing spider mite populations in the field. Abamectin at selective sublethal concentrations (i.e., 0.012~0.06 ppm) could be of value in adjusting predator/prey ratios in integrated management of spider mites.

• Asia Marketing Journal
• /
• v.7 no.3
• /
• pp.53-76
• /
• 2005

With rapid technological and market change, new product development (NPD) complexity is a significant issue that organizations continually face in their development projects. There are numerous factors, which cause development projects to become increasingly costly & complex. A product is more likely to be successfully developed and marketed when the complexity inherent in NPD projects is clearly understood and carefully managed. Based upon the previous studies, this study examines the nature and importance of complexity in developing new products and then identifies several issues in managing complexity. Issues considered include: definition of complexity : consequences of complexity; and methods for managing complexity in NPD projects. To achieve high performance in managing complexity in development projects, these issues need to be addressed, for example: A. Complexity inherent in NPD projects is multi-faceted and multidimensional. What factors need to be considered in defining and/or measuring complexity in a development project? For example, is it sufficient if complexity is defined only from a technological perspective, or is it more desirable to consider the entire array of complexity sources which NPD teams with different functions (e.g., marketing, R&D, manufacturing, etc.) face in the development process? Moreover, is it sufficient if complexity is measured only once during a development project, or is it more effective and useful to trace complexity changes over the entire development life cycle? B. Complexity inherent in a project can have negative as well as positive influences on NPD performance. Thus, which complexity impacts are usually considered negative and which are positive? Project complexity also can affect the entire organization. Any complexity could be better assessed in broader and longer perspective. What are some ways in which the long-term impact of complexity on an organization can be assessed and managed? C. Based upon previous studies, several approaches for managing complexity are derived. What are the weaknesses & strengths of each approach? Is there a desirable hierarchy or order among these approaches when more than one approach is used? Are there differences in the outcomes according to industry and product types (incremental or radical)? Answers to these and other questions can help organizations effectively manage the complexity inherent in most development projects. Complexity is worthy of additional attention from researchers and practitioners alike. Large-scale empirical investigations, jointly conducted by researchers and practitioners, will help gain useful insights into understanding and managing complexity. Those organizations that can accurately identify, assess, and manage the complexity inherent in projects are likely to gain important competitive advantages.

• Journal of Korean Society of Forest Science
• /
• v.32 no.1
• /
• pp.36-63
• /
• 1976

The purpose of this study is to elucidate the genetic variation of the natural forest of Pinus densiflora. Three natural populations of the species, which are considered to be superior quality phenotypically, were selected. The locations and conditions of the populations are shown in table 1 and 2. The morphological traits of tree and needle and some other characteristics were presented already in our first report of this series in which population and family differences according to observed characteristics were statistically analyzed. Twenty trees were sampled from each populations, i.e., 60 trees in total. During the autumn of 1974, matured cones were collected from each tree and open-pollinated seeds were extracted in laboratory. Immediately after cone collection, in closed condition, the morphological characteristics were measured. Seed and seed-wing dimensions were also studied. In the spring of 1975, the seeds were sown in the experimental tree nursery located in Suweon. And in the April of 1976, the 1-0 seedlings were transplanted according to the predetermined experimental design, randomized block design with three replications. Because of cone setting condition. the number of family from which progenies were raised by populations were not equal. The numbers of family were 20 in population 1. 18 in population 2 and 15 in population 3. Then, each randomized block contained seedlings of 53 families from 3 populations. The present paper is mainly concerned with the variation of some characteristics of cone, seed, needle, growth performance of seedlings, and chlorophyll and monoterpene compositions of needles. The results obtained are summerized as follows. 1. The meteorological data obtained by averaging the records of 30 year period, observed from the nearest station to each location of populations, are shown in Fig. 3, 4, and 5. The distributional pattern of monthly precipitation are quite similar among locations. However, the precipitation density on population 2, Seosan area, during growing season is lower as compared to the other two populations. Population 1. Cheong-song area, and population 3, Pyong-chang area, are located in inland, but population 2 in the western seacoast. The differences on the average monthly air temperatures and the average monthly lowest temperatures among populations can hardly be found. 2. Available information on the each mother trees (families) studied, such as age, stem height, diameter at breast height, clear-bole-length, crown conditions and others are shown in table 6,7, and 8. 3. The measurements of fresh cone weight, length and the widest diameter of cone are given in Tab]e 9. All these traits arc concerned with the highly significant population differences and family differences within population. And the population difference was also found in the cone-index, that is, length-diameter ratio. 4. Seed-wing length and seed-wing width showed the population differences, and the family differences were also found in both characteristics. Not discussed in this paper, however, seed-wing colours and their shapes indicate the specificity which is inherent to individual trees as shown in photo 3 on page 50. The colour and shape are fully the expression of genetic make up of mother tree. The little variations on these traits are resulted from this reason. The significant differences among populations and among families were found in those characteristics, such as 1000-seed weight, seed length, seed width, and seed thickness as shown in table 11. As to all these dimensions, the values arc always larger in population 1 which is younger in age than that of the other two. The population differences evaluated by cone, seed and seed-wing sizes could partly be attributed to the growth vigorousity. 5. The values of correlation between the characteristics of cone and seed are presented in table 12. As shown, the positive correlations between cone diameter and seed-wing width were calculated in all populations studied. The correlation between seed-wing length and seed length was significantly positive in population 1 and 3 but not in population 2, that is, the r-value is so small as 0.002. in the latter. The correlation between cone length and seed-wing length was highly significant in population 1, but not in population 2. 6. Differences among progenies in growth performances, such as 1-0 and 1-1 seedling height and root collar diameter were highly singificant among populations as well as families within population(Table 13.) 7. The heritability values in narrow sense of population characteristics were estimated on the basis of variance components. The values based on seedling height at each age stage of 1-1 and 1-0 ranged from 0.146 to 0.288 and the values of root collar diameter from 0.060 to 0.130. (Table 14). These heritability values varied according to characteristics and seedling ages. Here what must be stated is that, for calculation of heritability values, the variance values of population was divided by the variance value of environment (error) and family and population. The present authors want to add the heritability values based on family level in the coming report. It might be considered that if the tree age is increased in furture, the heritability value is supposed to be altered or lowered. Examining the heritability values studied previously by many authors, in pine group at age of 7 to 15, the values of height growth ranged from 0.2 to 0.4 in general. The values we obtained are further below than these. 8. The correlation between seedling growth and seed characteristics were examined and the values resulted are shown in table 16. Contrary to our hypothetical premise of positive correlation between 1-0 seedling height and seed weight, non-significance on it was found. However, 1-0 seedling height correlated positively with seed length. And significant correlations between 1-0 and 1-1 seedling height are calculated. 9. The numbers of stomata row calculated separately by abaxial and adaxial side showed highly significant differences among populations, but not in serration density. On serration density, the differences among families within population were highly significant. (Table 17) A fact must be noted is that the correlation between stomata row on abaxial side and adaxial side was highly significant in all populations. Non-significances of correlation coefficient between progenies and parents regarding to stomata row on abaxial side were shown in all populations studied.(Table 18). 10. The contents of chhlorophyll b of the needle were a little more than that of chlorophyll a irrespective of the populations examined. The differences of chlorophyll a, b and a plus b contents were highly significant but not among families within populations as shown in table 20. The contents of chlorophyll a and b are presented by individual trees of each populations in table 21. 11. The occurrence of monoterpene components was examined by gas liquid chromatography (Shimazu, GC-1C type) to evaluate the population difference. There are some papers reporting the chemical geography of pines basing upon monoterpene composition. The number of populations studied here is not enough to state this problem. The kinds of monoterpene observed in needle were ${\alpha}$-pinene, camphene, ${\beta}$-pinene, myrcene, limonene, ${\beta}$-phellandrene and terpinolene plus two unknowns. In analysis of monoterpene composition, the number of sample trees varied with population, I.e., 18 families for population 1, 15 for population 2 and 11 for population3. (Table 22, 23 and 24). The histograms(Fig. 6) of 7 components of monoterpene by population show noticeably higher percentages of ${\alpha}$-pinene irrespective of population and ${\beta}$-phellandrene in the next order. The minor Pinus densiflora monoterpene composition of camphene, myrcene, limonene and terpinolene made up less than 10 percent of the portion in general. The average coefficients of variation of ${\alpha}$-pinene and ${\beta}$-phellandrene were 11 percent. On the contrary to this, the average coefficients of variation of camphene, limonene and terpinolene varied from 20 to 30 percent. And the significant differences between populaiton were observed only in myrcene and ${\beta}$-phellandrene. (Table 25).

• Applied Biological Chemistry
• /
• v.8
• /
• pp.29-37
• /
• 1967

Citrus fruits of ten varieties grown in Chaeju island and a few other fruits for the comparison were analyzed to determined the contents of crude fat, crude fiber, total carbohydrates, macroelements and ash. Acids and sugars in fruit juices were also determined and the characteristic of neutralization of fruit juices were investigated. 1. The per cent of edible part of citrus fruits having the range of 48.5(Daingwoochi) to 72(Onju) were lower than that of other fruits. It was lower by about 8 per cent than that of the same variety produced in U.S.A. It was shown that the amount of rind per fruit might be increased in the citrus fruit grown in the low annual temperature. 2. The content of crude protein were around 1% and higher than other's. The contents of crude fat were below 0.1% in three varieties and over 0.1 in others. The contents of crude fiber were between 0.3 to 0.8% and the fruits with the high content of crude protein were inclined to have the high content of crude fiber and it was also shown that the low annual temperature was inclined to increase the amount of crude fiber per fruit. 3. The amount of total acid were from 19.5 m.e per 100 g of fresh fruit in Byongkyul to 44.2 m.e in Daingwoochi. The high percentage of titrable acid was over 90 in two sour varieties, Daingwoochi and Hakyul having pH below 3 and the high content of total acid. These two varieties were above 10 in the ratio of total acid in the edible part to the total acid in the rind(total acid in edible part/total acid in the rind). The content of combined acid was lower than that of titrable acid in the edible part and vice versa in the rind. 4. Navel was highest as 12.82% in the total sugar content and the lowest content was 4.9% of Hakyul. The contents of reducing sugar in the citrus fruits were about half of that in other fruits. The ratio of total sugar to titrable acid (sugar/acid: the grade of sweet taste) were lower than foreign products . 5. From the titration curves of fruit juices the characteristic of neutralization of juices could be grouped in three types, and other values, that is, pH, the content of total acid, the percentage of combined acid, the ratio of total acids in edible part and rind, the content of sugar, and the grade of sweet taste were also devided into the same three categories. 6. The contents of macroelements were different along to the each part of fruit. The content, in the seed were high and the ones in the rind were low. The contents of each element were in the order of $K_2O>N>P_2O_5{\gtrless}CaO{\gtrless}MgO$ in the edible part, $K_2O>N>CaO>P_2O_5{\gtrless}MgO$ in the rind, $N>K_2O>P_2O_5>CaO>MgO$ in the seed. The content of potassium was especially high in Marumeru and Hakyul and the content of calcium in citrus fruit was higher than others.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.15 no.1
• /
• pp.1-25
• /
• 1982

Limnological study on the physico-chemical properties and biological characteristics of the Lake Ok-Jeong was made from May 1980 to August 1981. For the planktonic organisms in the lake, species composition, seasonal change and diurnal vertical distribution based on the monthly plankton samples were investigated in conjunction with the physico-chemical properties of the body of water in the lake. Analysis of temperature revealed that there were three distinctive periods in terms of vertical mixing of the water column. During the winter season (November-March) the vertical column was completely mixed, and no temperature gradient was observed. In February temperature of the whole column from the surface to the bottom was $3.5^{\circ}C$, which was the minimum value. With seasonal warming in spring, surface water forms thermoclines at the depth of 0-10 m from April to June. In summer (July-October) the surface mixing layer was deepened to form a strong thermocline at the depth of 15-25 m. At this time surface water reached up to $28.2^{\circ}C$ in August, accompanied by a significant increase in the temperature of bottom layer. Maximum bottom temperature was $r5^{\circ}C$ which occurred in September, thus showing that this lake keeps a significant turbulence Aehgh the hypolimnial layer. As autumn cooling proceeded summer stratification was destroyed from the end of October resulting in vertical mixing. In surface layer seasonal changes of pH were within the range from 6.8 in January to 9.0 in guutuost. Thighest value observed in August was mainly due to the photosynthetic activity of the phytoplankton. In the surface layer DO was always saturated throughout the year. Particularly in winter (January-April) the surface water was oversaturated (Max. 15.2 ppm in March). Vertical variation of DO was not remarkable, and bottom water was fairly well oxygenated. Transparency was closely related to the phytoplankton bloom. The highest value (4.6 m) was recorded in February when the primary production was low. During summer transparency decreased hand the lowest value (0.9 m) was recorded in August. It is mainly due to the dense blooming of gnabaena spiroides var. crassa in the surface layer. A. The amount of inorganic matters (Ca, Mg, Fe) reveals that Lake Ok-Jeong is classified as a soft-water lake. The amount of Cl, $NO_3-N$ and COD in 1981 was slightly higher than those in 1980. Heavy metals (Zn, Cu, Pb, Cd and Hg) were not detectable throughout the study period. During the study period 107 species of planktonic organisms representing 72 genera were identified. They include 12 species of Cyanophyta, 19 species of Bacillariophyta, 23 species of Chlorophyta, 14 species of Protozoa, 29 species of Rotifera, 4 species of Cladocera and 6 species of Copepoda. Bimodal blooming of phytoplankton was observed. A large blooming ($1,504\times10^3\;cells/l$ in October) was observed from July to October; a small blooming was present ($236\times10^3\;cells/l$ in February) from January to April. The dominant phytoplankton species include Melosira granulata, Anabaena spiroides, Asterionella gracillima and Microcystis aeruginota, which were classified into three seasonal groups : summer group, winter group and the whole year group. The sumner group includes Melosira granulate and Anabaena spiroides ; the winter group includes Asterionella gracillima and Synedra acus, S. ulna: the whole year group includes Microtystis aeruginosa and Ankistrodesmus falcatus. It is noted that M. granulate tends to aggregate in the bottom layer from January to August. The dominant zooplankters were Thermocpclops taihokuensis, Difflugia corona, Bosmina longirostris, Bosminopsis deitersi, Keratelle quadrata and Asplanchna priodonta. A single peak of zooplankton growth was observed and maximum zooplankton occurrence was present in July. Diurnal vertical migration was revealed by Microcystis aeruginosa, M. incerta, Anabaena spiroides, Melosira granulata, and Bosmina longirostris. Of these, M. granulata descends to the bottom and forms aggregation after sunset. B. longirostris shows fairly typical nocturnal migration. They ascends to the surface after sunset and disperse in the whole water column during night. Foully one species of fish representing 31 genera were collected. Of these 13 species including Pseudoperilnmpus uyekii and Coreoleuciscus splendidus were indigenous species of Korean inland waters. The indicator species of water quality determination include Microcystis aeruginosa, Melosira granulata, Asterionelta gracillima, Brachionus calyciflorus, Filinia longiseta, Conochiloides natans, Asplanchna priodonta, Difflugia corona, Eudorina elegans, Ceratium hirundinella, Bosmina longirostris, Bosminopsis deitersi, Heliodiaptomus kikuchii and Thermocyclops taihokuensis. These species have been known the indicator groups which are commonly found in the eutrophic lakes. Based on these planktonic indicators Lake Ok-Jeong can be classified into an eutrophic lake.

• Journal of Chest Surgery
• /
• v.36 no.12
• /
• pp.929-936
• /
• 2003

We analysed the surgical outcomes of immediate reoperations after mitral valve repair. Material and Method: Eighteen patients who underwent immediate reoperation for failed mitral valve repair from April 1995 through July 2001 were reviewed retrospectively. There were 13 female patients. The mitral valve disease was regurgitation (MR) in 12 patients, stenosis (MS) in 3, and mixed lesion in 3. The etiologies of the valve disease were rheumatic in 9 patients, degenerative in 8, and endocarditis in 1. The causes of reoperation was residual MR in 13 patients, residual MS in 4, and rupture of left ventricle in 1. Fourteen patients had rerepair for residual mitral lesions (77.8%) and four underwent replacement. Result: There was no early death. After mean follow-vp of 33 months, there was one late death. Echocardiography revealed no or grade 1 of MR (64.3%) in 9 patients and no or mild MS in 11 patients (78,6%). Reoperation was done in one patient. The cumulative survival and freedom from valve-related reoperation at 6 years were 94% and 90%, respectively. The cumulative freedom from recurrent MR and MS at 4 years were 56% and 44%, respectively. Conclusion: This study suggests that immediate reoperation for failed mitral valve repair offers good early and intermediate survival, and mitral valve rerepair can be successfully performed in most of patients. However, because mitral rerepair have high failure rate, especially in rheumatic valve disease, adequate selections of valvuloplasty technique and indication are important to reduce the failure rate of mitral rerepair.

• Journal of Animal Science and Technology
• /
• v.45 no.2
• /
• pp.229-240
• /
• 2003

An in vitro test and a broiler feeding trial were conducted to test the effect of hydrothermal treatment of wheat bran on phytate-P degradation and it’s feeding effect on performance of broilers. Hydrothermal treatment of wheat bran was carried out at 55$^{\circ}C$ with pH 5.5 buffer solution. Phytate-P content of wheat bran decreased quadrically as the wheat bran: buffer solution ratio increased from 1:0.5 to 1:5. Phytate-P degradation was not significantly affected by incubation times above 10 min., drying temperature (55$^{\circ}C$, 65$^{\circ}C$ and 75$^{\circ}C$) or pH of the buffer solution (5.5 and 7.0). A feeding trial was conducted with 240 sex separated d-old broiler chickens (Ross$^{\circledR}$). Broilers were randomly housed to 24 cages of 10 birds each. Six cages (3 of each sex) were assigned to 4 treatments: Control-normal level of non-phytate-P (NPP); LP-low NPP treatment which had 0.1% lower NPP than Control; LPWB-LP with wheat bran which provided 475 IU of plant phytase per kg diet; LPHWB-LP with hydrothermally treated wheat bran. Results of the feeding trial showed that broilers in the LP treatment gained significantly less than other treatments in starter period (1-21d) but only male broilers for growing LP gained significantly less than Control in the grower (22-35d) and overall period. There were no significant differences in weight gain among the birds of LPWB, LPHWB and Control. Feed intake during the overall period was not significantly different between LPWB and Control but that of LP was lower than LPHWB and that of LPHWB was lower than Control. Feed/gain ratio was significantly lower in LPHWB and LP than in Control and LPWP. Mortality was highest in LPHWB. Availability of crude fat, crude ash and Ca was significantly lower in LP than other treatments. Availability of P and Zn was higher in LPWB and LPHWB than in Control and LP. Availability of P, Mg and Zn was highest in LPHWP treatment. Excretion of P was significantly lower in low NPP treatments than in Control. Serum Ca level was highest whereas serum P level was lowest in LP. Tibial crude ash content was higher in wheat bran treatments, but lower in LP than Control. However, tibial Ca content was higher in Control and LP than wheat bran treatments. Tibial P content of LP and LPWB was lower than Control. However, tibial content of Fe was highest in LP. It was concluded that wheat bran, a source of plant phytase, could be used in low NPP broiler diets to prevent the depression of performance. Reduction of P excretion can be achieved concomitantly. Hydrothermal treatment of wheat bran was effective in improving utilizability of some minerals but was not effective in improving performance of broilers.

• Korean Journal of Weed Science
• /
• v.15 no.4
• /
• pp.254-261
• /
• 1995

The nationwide weed survey was conducted in lowland rice fields over whole country of Korea in 1992 in order to determine a change of weed community and to identify a major dominant weed species and/or problem weed. Based on morphological characteristics of weeds, population ratio of broad leaf weed was 42.6%, grasses weed-9.0%, sedges-33.4% and others were 15.0%. Annual weed was 33.4% while perennial weed was 66.6% in terms of life cycle of weeds. Meanwhile, there was different weed occurrence as affected by planting method of the rice plant. In hand transplanted paddy fields predominant weed species was Sagittaria trifolia L., Monochoria vaginalis Presl., and Aneilema japonica Kunth. In machine transplanted rice fields of infant and young rice seedling Eleocharis kuroguwai Ohwi. and S. trifolia L. were more predominant. There was high occurrence of M. vaginalis, Echinochloa crus-galli L., and Leesia japonica Makino in water seeding while E. crus-galli and Cyperus serotinus Rottb. were predominant weed species in dry seeded rice. Monoculture of the rice plant would cause to high occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and Sagittaria pygmaea Miq and there was higher population of S. trifolia, S. pygmaea, M. vaginalis, E crus-galli, and E. kuroguwai in double cropping system based on rice culture. In particular, there was high different weed occurrence under different transplanting times. E. kuroguwai, S. trifolia, S. pygmaea, M. vaginalis, and C. serotinus were higher population at the transplanting of 25 May and S. trifolia, E crus-galli, C. serotinus, and M. vaginalis at 10 June and S. pygmaea, E. kuroguwai, M. vaginalis, S. trifolia, and E. crusgalli at 25 June in Korea, respectively. Autumn tillage in terms of tillage time would cause more predominant weed species such as S. trifolia, E. kuroguwai, M. vaginalis, and S. pygmaea while spring tillage was higher population of E. kuroguwai, S. trifolia, E. crusgalli, M. vaginalis, and S. pygmaea. In plain area of paddy field there was higher occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and S. pygmaea and in mid-mountainous area S. trifolia, E. kuroguwai, M. vaginalis, E. crus-galli, and Ludwigia prostrate Roxb. while in mountainous area S. trifolia, M. vaginalis, Potamogeton distinctus Ben., E. kuroguwai, and E. crus-galli were. In 1992 the most ten predominant weed species at the rice field of Korea based on summed dominant ratio(SDR) were E. kuroguwai > S. trifolia > E. crus-galli > M. vaginalis > S. pygmaea > C. serotinus > L. prostrate > P. distinctus > A. japonica > Scirpus juncoides Roxb.

• Journal of Embryo Transfer
• /
• v.20 no.2
• /
• pp.177-184
• /
• 2005

This study was conducted to investigate the effects of recombinant bovine somatotropin (rbST) injection on conception and parturition rates in normal or repeat breeding Hanwoo. We treated 462 cows containing 79 repeat-breeding cows of multiparous and allocating 5 treatment groups. Treatment 1 (T1) was injection of 2ml saline (for pseudo treatment), T2 was one injection of rbST 250mg into the tailhead region at the estrus, T3 was twice injection of rbST 250mg both at the time of insemination and again 10 to 14 day later, T4 was once injection of rbST 500mg at insemination and T5 was twice injection of 500mg rbST both at the time of insemination and again 10 to 14day later respectively. In rbST treated groups, timed artificial inseminations (TAI) were performed fellowing estrus synchronization. 100 us GnRH was injected into the scapula region on Day 0, 25mg $PGF_2{\alpha}$ was injected on Day 7 for degeneration of corpus luteum (CL) and 100ug GnRH was injected for inducing the synchronization. The results are as fellows; When normal Hanwoo were inseminated once with rbST administration, the pregnancy rate of T2 $(67.5\pm18.48\%)$ were higher than control $(52.4\pm9.72\%)$, while the pregnancy rate of T4 $(63.3\pm5.77\%)$ were significantly higher (p.<0.05) than control $(39.3\pm12.89\%)$ in repeat breeder Hanwoo. The parturition rates of normal Hanwoo were no differences among the treatments but were significant different in repeat breeder Hanwoo (p<0.05). When the estrous was induced by Ovsynch and inseminated once with rbST administration, the pregnancy rates of T2 was $12.5\%$ higher than control in normal Hanwoo, T4 $(80.0\%)$ was highest among the treatments (p<0.05) in repeat breeder Hanwoo. When normal Hanwoo were inseminated once with rbST administration, the pregnant period was $282.7\~284.8$ days and the body weight was $25.1\~25.9kg$, there were no difference among the treatments. The ratio of sex was almost same without T4 (male vs. female=18:9). In repeat breeder Hanwoo, pregnant period was 280.4~289.3 day and body weight was $23.0\~26.6kg$, it had no difference among the treatments. The sex ratio were similar to normal Hanwoo except T4 (M : F=2 : 8). In conclusion, the pregnancy and parturition rate by once insemination could be improved by the administration of rbST 250mg in normal Hanwoo or 500mg in repeat breeder Hawoo.

• Applied Biological Chemistry
• /
• v.20 no.1
• /
• pp.147-155
• /
• 1977

In this experiment, we expected yield increase depending on the control of ineffective tiller, heightening of effective tillering ratio and continuous supply of nitrogen until later growth stage of rice plant by deep layer split application. Treats were applied at Tongil and Jinheung variety, clayey loam and sandy loam soil, and drained and non-drained condition. Nitrogenous fertilizer application wab adopted as liquefied(50%) and lumped (50% and 80%) fertilizer at 12cm depth of soil before 35 days of rice heading time against the standard soil surface application. The results are summarized as follaw. 1. a. Jinheung showed great variant width of tiller numbers per rice plant growth stage, and low effective tillering ratio at soil surface dressing. But in the case of deep layer split application, the number of tiller increased normally, and effective tillering ratio was high. b. At Tonsil, the width of increase and decrease range of effective tiller number between soil surface dressing and deep layer split application was not so high as Jinheung. Deep layer split application of 80% lumped fertilizer showed maximum effective tillering ratio ($83%{\sim}93%$). C. In the case of Jinheung, it was supposed that deep layer split application of 80% lumped fertilizer was excessive nitrogen quantity. d. Effective tillering ratio was higher than Tonsil at Jinheung. 2. The number of grains per hill was increased by the deep layer split application, but the ripening ratio was decreased inversely with the increase of total grain number. 3. Length of top leaves was elongated at Jinheung by deep layer split application. It showed significant correlation between top leaves length and grain yield. 4. Deep layer split application inclosed N content of harvested straw. Yield and N content of straw showed possitive correlation. 5. The ratio of unhulled grain yield per straw weight was increased by deep layer splication. This ratio was higher at Jinheung than Tonsil. 6. Grain yield was appeared in order of 80% lumped fertilizer>50% lumped fertilizer>50% liquefied fertilizer>surface dressing by the deep layer split application. The yield increasing factors were the increasing of effective tillering ratio, number of panicles per hill and number of ripening grains per hill. 7. Grain yield was increased at Tongil in sandy loam soil and at Jinheung in clayey loam soil by deep layer split application. 8. The grain yield was increased at drained conditions of clayey loam soil and non-drained conditions of sandy loam soil. But in the case of 80% lumped fertilizer of deep layer split application at the sandy loam soil, the yield was not increased at non-drained conditions. 9. The effect of yield increase by deep layer split application comparing with the surface dressing was higher at Tonsil than ginheung, in spite of low ripening ratio of Tonsil caused by low temperature at heading and harvesting time.