• Research in Plant Disease
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• v.8 no.1
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• pp.1-10
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• 2002

Climate in the year of 2001 could be summarized as severe drought from March to May, unusually high temperature in whole plant growth periods and clear weather condition especially in harvesting time of September and October without any typoons. In rice, major diseases such as leaf and panicle blast, bacterial blight, sheath blight and bacterial grain rot developed little due to unfavorable weather conditions, however, brown spot occurred severely due partly to the reduced use of N-fertilizer, Rice stripe virus infection was unusually high mainly in the west coast areas with four times more diseaseD area campared to the previous year, In pepper phytophthora blight was extremely severe in Cheonnam and Cheonbuk provinces, where had frequent rainfalls during growing period. Incidence of major diseases of tomato and cucumber in 2001 was relatively mild. In watermelon, penicillium fruit rot, one of the peculiar disease, spread over major production areas, whereas CGMMV, usually severe in every years was much reduced. Watermelon plants growing in open-fields were more severely diseased than those in plastic houses. Major diseases of chinese melon and strawberry occurred slightly and in particular, sudden wilt syndrome of chinese melon which was severe in 2000 showed mild infections in 2001. Incidence of white rot of garlic and onion was much lower unlike other years due mainly to spring drought and high temperature in the growing period. Infected area of potato bacterial wilt tended to increase in 2001 while fusarium wilt of sweetpotato was decreased. Apple diseases were generally mild, but powdery mildew of pear increased sharply. Barley scab was not severe as seen in other years.

• Research in Plant Disease
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• v.21 no.3
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• pp.235-242
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• 2015

A 2014 nationwide survey in radish fields investigated the distribution of common viruses and possible emerging viruses. Radish leaves with virus-like symptoms were collected and 108 samples assayed by RT-PCR using specific primers for Radish mosaic virus (RaMV), Cucumber mosaic virus (CMV), and Turnip mosaic virus (TuMV); 47 samples were TuMV positive, and RaMV and CMV were detected in 3 and 2 samples, respectively. No samples showed double infection of TuMV/RaMV, or RaMV/CMV, but two double infections of TuMV/CMV were detected. TuMV isolates were sorted by symptom severity, and three isolates (R007-mild; R041 and R065-severe) selected for BLAST and phylogenetic analysis, which indicated that the coat protein (CP) of these isolates (R007, R041, and R065) have approx. 98-99% homology to a previously reported TuMV isolate. RaMV CP showed approx. 99% homology to a previously reported isolate, and the CMV CP is identical to a previously reported Korean isolate (GenBank : GU327368). Three isolates of TuMV showing different pathogenicity (degree of symptom severity) will be valuable to study determinants of pathogenicity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.1
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• pp.30-36
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• 1979

The fertilizations of cv Palkweng, Noupoung, and TN 1 which were crossed artificially at 2$0^{\circ}C$ and 3$0^{\circ}C$ were examined. The meiosis and the rate of maturity of the above 3 cultivars, Iri #326, Milyang #29, Suwon #264, and 3 others which were transplated at different times in paddy field were examined, and the results of which were as follows. 1. Palkweng at 3$0^{\circ}C$ was fertilized within 1.5~4.0 hours ,after pollination and at 20\circ C was done within 2.8~4.5 hours after pollination. 2. Noupoung and TNI at 3$0^{\circ}C$ were fertilized within 2.0~5.5 hours after pollination and at 2$0^{\circ}C$ were done within 3.0~6.0 hours after pollination. 3. The rates of fertilization of the cultivated rice plants at 2$0^{\circ}C$ were dropped in general. TN 1 at 2$0^{\circ}C$ was often fertilized abnormally. 4. In the development of embryo, Palkweng was the earliest at 3$0^{\circ}C$ and TN 1 was the earliest at 2$0^{\circ}C$. 5. Although the time of transplant was late, the pollens of Palkweng was normal because the meiosis of that was normal. but the pollens of TNI was sterile in general because of the abnormal meiosis.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.1
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• pp.39-44
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• 2001

Growth characters and productivities of corn varieties were compared to provide the basic data to the famers that in order to select the good corn varieties at Deakwanryoung district of Korea. Currently cultivated 8 recommended corn varieties and Suwon 19ho as check variety were used in this experiment and experimental design was randomized complete block with three replications. Resarch results obtained at Deakwanryoung branch (sea love 800m) of National Livestock Research Institute in 1999 are summarized as follows. Culm lengths of DK501 and GL4899 among corn varieties were shorter as 180cm and 198cm, respectively and rest of varieties were more or less 230cm and no difference among varieties. Inflorescence height was lower in varieties showing low culm length, and inflorescence heights of PK3525 and DK729 were higher about 10～15cm than those of other varieties. Stem diameters of all varieties except DK501 were thicker compared to check variety, Suwon 19ho and P3144W was thickest. Leaf numbers of late maturing DK729 and G4743 were higher as average 12 and 12.3 per plant, respectively. Silking dates among varieties were ranged from August 10 to 20 showing 10 day difference and DK501 was earliest as August 10 and G4743 was latest as August 20. Ear rates of early silking varieties were more than 46% and late silking varieties were less than 40%(P>0.1). Dry matter and TDN yield of P3351 was highest as 24,710 and 17,470kg/ha respectively, and DK729 and G4743 were second and third in order. In conclusion. early and medium maturing variety. P3352 with high yield and good growth characters was desirable at Deakwanryoung district of Korea.

• The Korean Journal of Mycology
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• v.10 no.2
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• pp.85-88
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• 1982

In order to investigate flight number of ascospores of the wheat scab fungus as a primary inoculum, the experiment was undertaken at three localities including Suweon during the two years 1979 to 1980. Ascospore fllight of the fungus was begun at the first part of April, and amounts of flight number of ascospores were varied by different localities. It showed a tendency that large number of ascospore fllight was proportionally resulted by higher amounts of rainfall. As a result, a high positive correlation was obtained between flight number of ascospores of the fungus and amounts of rainfall.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.60-69
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• 2005

The herbicide molinate has been detected with high frequency in the main river during the growing season in Korea. To elucidate the exposure of molinate in agricultural environment, the persistence and the degradation characteristics of molinate were investigated in paddy ecosystems. The half-lives of molinate were 4.1 days with soil aquatic system, and 4.2 days in only aquatic system. Initial dissipation rate of molinate in water was greater with soil aquatic system than that of only aquatic system. Photolysis of molinate was occurred about 31.0% of molinate treated in pure water, when irradiated at 5,530 $J/cm^2$ by the xenon lamp, but its hydrolysis was stable. For the accelerated photolysis of molinate in aqueous solution, several photosensitizers were screened, showing that the hydroperoxide($H_2O_2$) and acetone were prominent among the chemical tested. When hydroperoxide and zinkoxide(ZnO) were used as photosensitizer, their photolysis were accelerated greater than 98% and 58% in aqueous solution, respectively. Elution rate of molinate as granular formulations in aqueous system was more than 90% in 30 hour at $35^{\circ}C$. Molinate concentration pattern in paddy water was rapidly decrease from treatment till 7 days in paddy rice field and its half-lives were 3.7 days($Y=1.9258{\times}e^{-0.1865X}$(r=-0.9402)).

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.191-195
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• 2014

Occurrence of soybean pod gall midge (SPGM), Asphondylia yushimai, and soybean pod damage caused by SPGM, and its control efficacy treated with ethofenprox 20EC were first observed at Miryang from 2006 to 2008 in Korea. The typical damage symptoms in soybean pod caused by SPGM were brownish coloration and malformation. By beating method occurrence of SPGM was observed from beginning bloom of soybean and its collected population increased with season until middle September. Soybean pod damage caused by SPGM was heaviest at seeding date of 10th May, followed by 11th June and 26th May. Control efficacy against SPGM sprayed with one time application of ethofenprox 20EC at different spray time in soybean reproductive stage was highest with 92.9% at R2.5, followed by 87.9% at R2 and 83.6% at R3, and was low from about 19 to 66% at other spray time. Accordingly, the most effective spray time of insecticide for control of SPGM in soybean field was found to be R2.5 which is between R2 and R3.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.431-435
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• 2015

Riptortus pedestris (Fabricius) is one of the important insect pests of leguminous crops, which occurs in most areas of South Korea. It is hard to distinguish each generation in crop fields since not only the longevity of adult R. pedestris is long but also the developmental period is short. Especially, the 2nd generation adults cause enormous damage to soybean while the occurrence time is synchronized with the podding stage of soybean. Controlling the 1st generation of R. pedestris helps to decrease the damage by decreasing the 2nd generation density. This study was conducted to distinguish between the 1st generation and the overwintering generation by using differences in body coloration which is dependent on the day-length during the nymph stage. In addition, the difference was verified by the population dynamics model of R. pedestris. The occurrence time of 1st generation adults could be considered when the summer form is 20% or more. These results will be used for beneficial management decisions to reduce the 2nd generation population.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.567-573
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• 2005

Compatability of films made of chitosan, gelatin, and their blends prepared by aqueous solution casting was investigated using a thermogravimetric analyzer(TGA) and a dynamic mechanical analyzer (DMA). TGA showed gelatin is more thermally stable than chitosan, and thermal stability of chitosan in blends was higher than that of pure chitosan due to interaction among functional groups of component polymers in blend. Glass transition temperature $(T_g)$ of blends was dependent on chitosan content of blends. Blend films exhibited good miscibility. Moisture and glycerol contents of blend strongly affected thermal properties of two component polymers.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.404-410
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• 2012

This study was conducted to examine effects of harvest time (09:00 vs. 14:00), precooling at $4^{\circ}C$ vs. no precooling, and storage temperature (4 vs. $8^{\circ}C$) on the storage life of 'Maehyang' strawberry fruits for export. Fruits at a 60% ripe stage were harvested from a commercial greenhouse in Gyeongsangnamdo, Jinju on May 4, 2010. Fruits were precooled by a forced draft cooling for three hours, transported for about 30 minutes and then stored, immediately. Small precoolers set in the farm were used for precooling. Fruits were placed in constant temperature chamber (4 or $8^{\circ}C$) after packaging using PVC wrap and a cardboard box. Fruits were examined for their changes in weight, hardness, Hunter color values, soluble solids content (SSC), and incidence of gray mold (Botrytis cinerea) during storage at a two days interval from May 6 to May 14, 2010. Hardness and SSC decreased as the ripening stage progressed. The Hunter's 'L' and 'a' value of fruit color decreased as time passed. Also, fresh weight decreased during storage at all temperatures. Soft rot appeared on epidermal tissues and followed by gray mold. Incidence of gray mold was greater at $8^{\circ}C$ storage temperature than in $4^{\circ}C$ storage temperature. However, no difference by the harvested time and precooling. The results indicate that effectiveness for keeping the freshness was best achieved by precooling at $4^{\circ}C$ and storage at $4^{\circ}C$, respectively.