• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.2
• /
• pp.195-201
• /
• 2012

It is important to determine the optimum harvesting time that impact decisively on the quality of vegetable waxy corns. In general, it takes 20~25 days from silking to harvest according to ecotype when waxy corn hybrids were sown in April. We identified the optimum harvesting time by the ecotypes and seeding dates for the establishment of corn double cropping system of waxy corn. It takes 23~25 days from silking to harvest regardless of ecotype, when waxy corns were sown at early in April or late in June. It takes 28~31 days when Chalok1, early maturing type, was sown between in July 10, and in July 30. It takes 29~31 days when Ilmichal, medium late maturing type, was sown between in July 10 and in July 20, but 39 days were required when sown at in July 30. The cumulative temperature for harvesting was about $1700^{\circ}C{\sim}2100^{\circ}C$. The minimum cumulative temperature from seeding to harvest was approximately $600^{\circ}C$. These results will be helpful to the farmers for determining the optimum harvest time of vegetable waxy corns.

• Journal of Animal Science and Technology
• /
• v.48 no.3
• /
• pp.443-452
• /
• 2006

The four rice(Oryza sativa L.) lines, previously demonstrated to have vigorous herbage production at the vegetative growth stage, were investigated for their growth traits, dry matter yield and feed value using the twice-cutting system that 1st-cut is harvested at panicle formation stage and 2nd-cut at the yellow ripen stage. The twice-cutting system is regarded as an effective method in the production of forage rice by escaping lodging and insect damages caused by the overgrowth and typhoon around the heading stage.The feed value of the twice-cut rice plant of there lines were compared with the control of normal, cutting at the yellow ripen stage. The relative feed value(RFV), the total digestible nutrient(TDN) and the crude protein(CP) content of the twice-cut straw were higher the control in every lines. However, the dry matter yield (DMY), represented by the summed forage production of 1st and 2nd cut-rice plant, were lower the control, and the DMY of straws were increase but grains were decrease for twice-cutting system. In addition, TDN yield showed the similar tendency with DMY.Recently, as one of the breeding aims the researches for improving the digestibility of rice straw have been required. In this regard, twice-cutting system is recognized with the fact that it has the effect which raises the digestibility of the straw. Especially, the 2nd cut of IR73111-B-R-15-3-1 line was similar to the control at the TDN yield of straw, and would be used as a breeding material for product the roughage of good quality.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.13 no.4
• /
• pp.89-99
• /
• 2005

The golf courses more than about 200 are operating in Korea. From the golf courses, a great amount of turfgrass clippings tend to increase, steadily. Materials used in the experiment were Creeping Bentgrass(CB), Kentucky Bluegrass(KB), Korean Lawngrass(KL), rice bran and composted chicken drop. Treatments are CB, KB, and KL. The temperature during the composting of all treatments increased rapidly and reached at the highest temperature($57.9^{\circ}C$, $67.8^{\circ}C$, $74.3^{\circ}C$) within 20 days, and then stabilized to the range of $35.2{\sim}41.6^{\circ}C$ at the 30th day. The pH values of all treatments decreased on the first day. However, they were increased rapidly after three days and decreased again on 10~20 days. The pH values of all treatments at the final day were stabilized to the low alkali levels. The contents of total carbon during the period of composting tend to decrease and total nitrogen was increased for factor of reduction of volume. CEC value of all treatments during the period of composting tends to increase. The round paper chromatogram of extracted solution of KL sample was the sharpest and clearest among all treatments. The G.I. values of CB, KB, and KL in 30th day of composting were about 95.1, 77.7, and 98.7 in germination test using chinese cabbage, respectively. Conclusively, all turfgrass clippings used in this experiment were composted well, suitable as composting products standardized by KSC. The maturity of the final compost samples is best in KL, followed by CB and KB treatments. The turfgrass compost can contribute to the plant cultivation for environment-friendly farm, and the results of this study can become the basic data of turfgrass clippings compost. Further research on the mixing ratio of each material is required to produce compost of good quality.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.1 no.1
• /
• pp.11-23
• /
• 2003

A study on the electrolytic dissolution of SUS-304 and Inconel-600 specimen was carried out in neutral salt electrolyte to evaluate the applicability of electrochemical decontamination process for recycle or self disposal with authorization of large amount of metallic wastes contaminated with uranium compounds generated by dismantling a retired uranium conversion plant in Korea. Although the best electrolytic dissolution performance for the specimens was observed in a Na2s04 electrolyte, a NaNO$_3$ neutral salt electrolyte, in which about 30% for SUS-304 and the same for Inconel-600 in the weight loss was shown in comparison with that in a Na$_2$SO$_4$ solution, was selected as an electrolyte for the electrochemical decontamination of metallic wastes with the consideration on the surface of system components contacted with nitric acid and the compatibility with lagoon wastes generated during the facility operation. The effects of current density, electrolytic dissolution time, and concentration of NaNO$_3$ on the electrolytic dissolution of the specimens were investigated. On the basis of the results obtained through the basic inactive experiments, electrochemical decontamination tests using the specimens contaminated with uranium compounds such as UO$_2$, AUC (ammonium uranyl carbonate) and ADU (ammonium diuranate) taken from an uranium conversion facility were performed in 1M NaNO$_3$ solution with the current density or In mA/$\textrm{cm}^2$. it was verified that the electrochemical decontamination of the metallic wastes contaminated uranium compounds was quite successful in a NaNO$_3$ neutral salt electrolyte by reducing $\alpha$ and $\beta$ radioactivities below the level of self disposal within 10 minutes regardless of the type of contaminants and the degree of contamination.

• Korean Journal of Soil Science and Fertilizer
• /
• v.20 no.3
• /
• pp.199-204
• /
• 1987

This study was conducted to verify the identity and the effects on soil improvements by the application of Barley stone which has been recently named as miraculous mineral on account of being propagandized as health stone because of several special effect of medicine, the supplement of micronutrients for agriculture, prevention against diseases and insects of plant, and the increase of nutrient holding capacity of soil. The results were summarized as follows; 1. Barley stone is considered as Diabase Porphyrite by the analysis of X-ray Diffraction, chemical composition and microspore's observation. This mineral stone called as Barley stone has been deducted because of being seen as if the feature was attatched with cooked barley and appearently scattered about feldspar's phenocryst on the dark-green stone base. 2. In chemical characteristics of barley stone, the pH 8.7 was higher but C.E.C. 9.0 me/100g was lower then those of other clay minerals such as Bentonite and Zeolite, and so barley stone material was not considered suitable for improvement of sandy loam soil. 3. Effects of Bentonite and Zeolite application on yield of paddy rice were 108-109% compare to non-treated plot, but Barley stone has not increased rice yield. Notwithstanding the increase of application of barely stone to 5 ton per 10a, the yield increase was not significantly showing only 102-103% and the effects of Peanut, hot pepper and chinese cabbage were not recognized either.

• Journal of Sericultural and Entomological Science
• /
• v.36 no.1
• /
• pp.8-25
• /
• 1994

The study was conducted to obtain the genetic information on heterosis and combining ability of the quantitative characters for F1 hybrid breeding in silkworms. Six parental varieties and each set of 30 diallel crosses in F1's were used as materials, and bred on the randomized complete block design with three replications. Fourteen characters were observed with the twenty samples in each tray. The data were analyzed for (1) heterosis and combining ability in F1 hybrid. The heterosis in the weight and the length of cocoon showed positively high at 24.51%, and 23.4%, respectively and the weight of the whole cocoon as well as the weight of the whole cocoon layer showed a siginificant heterosis ranging from 15.56% to 15.71% and from 17.14% to 19.01%, but the fifth and the total instar period showed negative heterosis. It was found that the combination between, C70XRomogua and N9 X Romogua showed highly a negative heterosis on the fifth instar period and for the cocoon weight. The female of N9+Sansuian and the male of Romogua X Sansurian have a high heterosis effect, on the cocoon shell weight, and Sansurian X Romogua(reciprocal) on the length and the weight of cocoon filament with no regard to sexuality. The significant maternal and cytoplasmic effect on heterosis of the cocoon weight and the cocoon shell weight were observed with the combinations, N9 X C5, N63 X C70 and on the length of the cocoon filament with the combinations, Sansurian X N63, Sansurian X C5, Sansurian X C70 and N9 X C70, N63 X C70 on the weight of cocoon filament. As mean squared of GCA, SCA and RCA were significant with these combining ability for all characters resulted from additive and non-additive altogether and there is a significant difference between reciprocals. Sansurian showed a negative GCA effect on the fifth and total larval duration, but the higher positive GCA effects took places with varieties N9 and C5 on the length, width, weight of cocoon, cocoon shell weight, percentage of cocoon shell weight, length and weight of cocoon filament, percentage of raw-silk with no regard to both generations and silkworm sexuality. The values of SCA between the cross combinations varied generation-wise and sex-wise. It was shown that SCA value for the fifth instar period was highly negative for Sansurian X C70, Romogua X C70, Sansurian X C5, Romogua X C5, but it was positive effect on the cocoon weight, cocoon shell weight with N9 X C5, and C70 X Sansurian, on the length of cocoon filament with N9 X C5, Romogua X Sansurian on the weight of cocoon filament between Romogua and N63 and on the percentage of raw-silk between the combination of Sansurian X Romoga.

• Korean Journal of Weed Science
• /
• v.15 no.1
• /
• pp.19-29
• /
• 1995

The effect of seeding depth on the growth, mesocotyl elongation and herbicidal response of rice(Oryza sativa L., Japonica type, cv. "Tongjin") and barnyardgrass(Echinochloa crus-galli Beauv. var orizicola Ohwi.) were studied in greenhouse experiments. Barnyardgrass growth as affected by different water depths was briefly tested. Rice and barnyardgrass were broadcast in soil into Oem, 1cm, 2cm and 3cm in seeding depth under dry direct-seeded condition. Butachlor(N-(buthoxymethyl)-2-chloro-N-(2,6-diethylphenyl) acetamide) at dose rate of 1800g ai/ha and thiobencarb(S-[(4-chlorophenyl)methyl] diethyl carbamothioate) at dose rate of 2100g and 4200g ai/ha were soil applied to them at 5 days after seeding. At 10 days after seeding, plants harvested to examine their growth as affected by seeding depth. Root length and shoot fresh weight of rice untreated was greatest in 1cm- and 3cm-seeding depth, respectively, however, mesocotyl did not elongate. While plant height of barnyardgrass grew regardless of seeding depth and water depth, but root length was greatest in 1cm-seeding depth of dry condition and reduced with increased water depth. And mesocotyl was elongated in only dry condition and its length increased with increased seeding depth. At 10 days after application thiobencarb applied pre-emergence inhibited plant height, and shoot fresh weight of rice in only 0cm-seeding depth under dry condition whereas was unaffected in above 1cm-seeding depth, similar to untreated control, and ever increased root length and root fresh weight of rice. On the other hand, shoot, root and leaf growth of barnyardgrass was, severely inhibited regardless of application rates and seeding depths. Reduction of shoot growth by treatment of herbicide was significantly greater than that of root growth. Consequently, reduction of barnyardgrass growth by treatment of thiobencarb did not be associated with seeding depth and mesocotyl elongation as affected by different seeding depth.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.1
• /
• pp.24-30
• /
• 2010

Comprehensive studies on seedling production and transplanting cultivation of waxy corn are necessary to fulfill the comsumer's preference for the high quality whole ear waxy corn and its year-round supply for higher price, and to escape marketing in a short period at harvest season. Two waxy corn hybrids (cv. Chalok# 1 and Chalok# 4) were used to study the effects of seeding date, nursery days and plug cell size on growth and yield of waxy corn, and to clarify the reliable transplanting date at the Experimental Field of the National Institute of Crop Science in 2007. The number of days from seeding to silking was increased as nursery days were extended, but the number of days from transplanting to silking was shortened comparing to the direct seeding. Number of days from seeding to silking was shorter by 9~12 days for Chalok# 1 than for Chalok# 4, while the number of days from seeding to silking was shorter by 12~15 days in the second cropping than in the first cropping. Culm length of transplanted waxy corns was decreased as the nursery days were extended. Culm length of seeded Chaok# 1 and Chaok# 4 were decreased by 17% and 24%, respectively, in the second cropping compared to those in the first cropping. Ear length was somewhat decreased as the nursery days were extended. Chalok# 1 in the second cropping the degree of decrease was much higher in second cropping than in first cropping of Chalok# 1. Comparing to the first cropping, number of marketable ears per 10a of Chalok# 1 decreased as high as 64%, while that of seeded Chalok# 4 decreased mere 12% in the second cropping.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.3
• /
• pp.261-272
• /
• 2008

This study was conducted to provide the fundamental data based on the agronomic characteristics of domestic aroma rice, widely cultivated domestic rice and foreign aroma rice for breeding of functional aromatic rice. Among the 104 varieties, all of domestic aroma rice and widely cultivated rice varieties were headed, 24 of 84 varieties of foreign aroma rice were not headed. The average heading date of domestic aroma rice Japonica types of domestic rice was later as 136 day, and Tongil types of domestic aroma rice were faster as 122 day. The average culm length of Indica types of foreign aroma rice was longer as 130 cm, and Tongil types of were shorter as 74 cm. The average panicle length of domestic aroma rice and traditional rice were about 21 cm, and Indica types of foreign aroma rice were longer as 29.5 cm. The average 1,000 grain weight of Tongil types of domestic aroma rice and was not a difference with the domestic aroma rice and was more 2.5 g than the Indica types of foreign aroma rice. The average ratio of grain width and length of Indica types of foreign aroma rice were highest as 3.29 (W/L), and the domestic traditional rice was lowest as 1.7 (W/L). The average fertility rate of the domestic aroma rice, the widely cultivated domestic rice, and the Japonica types of foreign aroma rice were above 89.7%, but the Indica types of foreign and the Tongil types of domestic aroma rice were below 65.4%. The average germination rate of foreign aroma rice were above 83.7%, and domestic aroma rice were above 90.4%. The non-glutinous rice were 64 varieties (84.2%) of total 104 accessions of material rice and the waxy rice were 7 varieties (1%). In the domestic aroma rice, Hyangmi2ho and Aranghyangchalbyeo has a mild aroma grade. In the foreign aroma rice, 22 of 40 varieties of Indica types and 9 of 16 varieties of Japonica types has a lightly aroma grade. And 13 varieties of widely cultivated domestic rice has a non-aroma grade.

• Horticultural Science & Technology
• /
• v.32 no.3
• /
• pp.279-288
• /
• 2014

To understand changes in composition and distribution of nutrients during early shoot growth of persimmon, organic compounds and inorganic elements of terminal shoots were analyzed for about 40 days from the time of foliation. Sample shoots were collected from mature 'Fuyu' trees for this three-year experiment and they were divided to stem, leaves, and the fruits including flower buds at the earliest stage. During shoot growth, concentration of soluble sugars increased in both leaves and fruits, but that of starch increased only in leaves. Those of amino acids tended to decrease in all the parts but there was no consistent change in proteins. As shoots grew, contents of all the organic compounds in a shoot increased, and they were especially higher in May leaves accounting for more than 60% of the shoot total for each nutrient. Along with shoot growth, concentrations of N and P gradually decreased in all three parts, while K decreased only in stem. However, those of Ca and Mg did not show notable changes in all the parts with wide variations depending on the year. Due to the quantitative increase in growth, contents of inorganic elements in a shoot increased in all the parts and the leaves accounted for 54-82% of the shoot total. At the cessation time of extension growth, a shoot contained 526-768 mg of soluble sugars, 245-844 mg of starch, 26-31 mg of amino acids, and 66-103 mg of proteins for three years. On the other hand, a shoot contained 203-388 mg of K, the greatest among the inorganic elements, followed by 132-159 mg of N. Changes of the nutrients in a shoot were much greater during the earlier stage of growth after foliation than during the later stage toward growth cessation, suggesting the importance of mobilizing reserve nutrients for the early growth of the shoots. The results of this study also suggested that the rate of nutrient changes, especially during the earlier stage of shoot growth, could be affected by environmental and cultural conditions.