• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.1-7
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• 2011

In order to enhance the fungicidal activity of the thifluzamide formulation against rice sheath blight, the surfactants which was able to facilitate the foliar uptake or increase the leaf deposit of thifluzamide on rice plants were selected, and the formulations containing the surfactants were tested to compare the fungicidal efficacy against the rice sheath blight with a control WP formulation. The WP suspension containing dodecaethylene glycol monohexadecyl ether as an activator increased the foliar uptake of thifluzamide on rice plants, but its fungicidal efficacy against rice sheath blight was decreased. The addition of the combined surfactants with either heptaethylene glycol monoisododecy ether or heptaethylene glycol monotridecyl ether and sodium dioctylsulfosuccinate to WP suspension increased the leaf deposition of thif1uzamide at around 5 times of that without a spreader-sticker that median control concentrations of thifluzamide against rice sheath blight were decreased to 4.4 mg $L^{-1}$ and 3.4 mg $L^{-1}$, respectively.

• Journal of Korean Academy of Nursing
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• v.3 no.3
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• pp.119-132
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• 1973

This study observed on habitual methods of toilet training for infants and toddlers in Korea thru 300 mothers at four medical institutions Ewha Woman′s University Hospital, Ewha Maternal and Child Health Center, Severance Hospital and Seoul National University Hospital) with a design to analyze beginning time, duration of period, methods employed, motives, equipments used, special terminology used for the subject training. The main purpose of this study was to generalize the proper methods of toilet training, and also to contribute a better psychological education for the mother and child. The results obtained from this study were as follows; 1. Majority of (67.3%) observed were in the age category between 30 and 40 years, and dominant numbers (64.7%) were housewives with high level of education and from middle class family background. 2. In the most cases (85%), toilet training was carried out by mothers(including wives who had a job) while more than half of mothers (53.7%) maintained their important motive for the training was "due to having high regard for cleanliness" 3. As for the time of beginning toilet training: finding indicated that starting period was decided (70%) at inconsiderate desertion of each mother. whereas, only minority group (30%) represents the cases where mother started the training when they consider tile child was physically and psychologically randy. Also greater number (77.7%) started bladder training prior to that of bowel. 4. It is noticeable that in course of training a large number of mothers (48.3%) applied strict training method when the child proper talenting, and the more rigid and strict in tile training. the more malformation of personality of the infant and toddler were seen after the training period (P<0.01). 5. Over the half of the total cases denoted (bowel 54.3%, bladder 67.7%) starting period before one year and in most cases (bowel 79.3%, bladder 729)the training was accomplished within 12 month, and therefore it was noted that earlier start(before 1 year) shortened the training period (with 12 month) . There was no significant difference between male and female infants in both starting period and duration of period in bladder training, however, in bowel training there was a tendency that female started earlier(7-12 months needed, 51.4%) than tile male (13-18 months needed, largest number 41.4%), and also in cases of female the period for needed for training were shorter than the cases of male. 6. Many a number (bowel 50.3%, bladder 97.7%) employed the method of continuous talenting at regular interval in accordance with that of child′s habit formed before training. Equipment used were various kinds, however, pieces of paper for male (45.5%) and piss pot or bedpost (42.3%) for female were common, on the other hand, "Eung-ga" for defecation (52.3%) and "Shii" for the urination (95.3%) were most standard expression that used during the training period.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.371-379
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• 2013

Anthracnose disease caused by Colletotrichum orbiculare, induces severe damage to cucurbits worldwide. Resistance of 112 commercial cultivars of cucurbits to C. orbiculare was evaluated. Seedlings of each cultivar at 2- to 3-leaf stage were inoculated with C. orbiculare KACC 40809 by spraying spore suspension of the fungus at a concentration of $4.0{\times}10^5$ spores/mL. Among the 36 cultivars of cucumber, 'Asiastrike', 'Tongilbaedadagi', 'Daeseon', 'Cheongrokmatjjang', 'Nokyacheongcheong', and 'Asianogak' were moderately resistant and the others were susceptible. All the tested cultivars of melon (33) and watermelon (4) showed highly susceptible response to C. orbiculare. On the other hand, the squash cultivars (17) represented less susceptibility to the fungus than the other cucurbits. Of the squash cultivars, 'Gammirak' and 'Teotbat' were resistant and 12 cultivars were moderately resistant. Among the rootstocks for cucurbits, ten cultivars including 'JjeuyakaEX', 'Nunbusyeo', 'Union', 'RS111', 'Ganggeuntoza', 'Hwangjaetoza', 'NO.8', 'Shintoza', 'Bulpaetoza', and 'Newtype' showed high resistance to the anthracnose pathogen. From the results, the resistant cultivars could be used as sources of resistance to cucurbits anthracnose (C. orbiculare) in the future breeding programs.

• Research in Plant Disease
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• v.16 no.3
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• pp.279-284
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• 2010

Clubroot caused by Plasmodiophora brassicae is a widespread disease that causes serious problems in many brassica growing areas. To establish more simple and reliable clubroot screening method of Chinese cabbage to P. brassicae using soil-drenching inoculation, the development of clubroot on Chinese cabbage according to several conditions such as soil type, inoculum concentration of P. brassicae GN-1 (race 9), plant growth stage and incubation period was studied. In a commercial horticulture nursery media soil (CNS), disease severity of the seedling according to inoculum concentration increased in a dose-dependent manner, but did not in mixture of CNS and upland soil (1:1, v/v). To facilitate and acquire precise result of resistance screening of Chinese cabbage to clubroot, 10-day-old seedlings should be inoculated by drenching the spore suspension of P. brassicae to give inoculum density of $4.0{\times}10^8$ spores/pot. To develop the disease, the inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days, and then cultivated in a greenhouse ($25{\pm}5^{\circ}C$) for five weeks. Under the optimum conditions, 25 clubroot-resistant (CR) and 3 clubroot-susceptible (CS) cultivars were tested for resistance to P. brassicae. All CR cultivars showed very clear resistance response, on the other hand all CS cultivars severly infected with the pathogen. The results suggest that this method is efficient screening method of Chinese cabbage for resistance to clubroot disease.

• Research in Plant Disease
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• v.23 no.4
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• pp.334-347
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• 2017

Bacterial wilt caused by Ralstonia solanacearum is an important disease in cultivation of chili pepper, causing plant death and significant yield losses. Cultivation of disease-resistant varieties is the most suitable measure to control bacterial wilt of chili pepper. To establish an efficient screening method for resistant chili pepper to R. solanacearum, six resistant or susceptible cultivars to the R. solanacearum were selected and the development of bacterial wilt on the cultivars according to several conditions was investigated. Drenching bacterial suspension into the cut roots using a scalpel was more simple and effective to distinguish resistant and susceptible cultivars than inoculation methods of root-dipping or soil-drenching without wounding. A resistant pepper, 'MC4' to R. solanacearum showed high resistance under the developed conditions which were 21- to 28-day-old pepper inoculated with $1{\times}10^8cfu/ml$ of bacterial suspension. On the other hands, the susceptible cultivars represented high disease severity under the conditions. These results indicated that we developed an efficient method to evaluate resistance of chili pepper cultivars against bacterial wilt. In addition, we successfully evaluated resistance degree of 140 commercial chili pepper cultivars to R. solanacearum using the developed method.

• Research in Plant Disease
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• v.26 no.3
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• pp.159-169
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• 2020

Pectobacterium carotovorum subsp. carotovorum (Pcc) causes bacterial soft rot on a wide range of crops worldwide, especially in countries with warm and humid climates. This study was conducted to establish an efficient screening method for resistant cultivars of Chinese cabbage to bacterial soft rot. Resistance degrees of 65 commercial Chinese cabbage cultivars to the Pcc KACC 10225 isolate were investigated. For further study, three Chinse cabbage cultivars (Taebong, Hadaejangkun, CR Alchan) showing different level of resistance to the bacterium were selected. The development of bacterial soft rot on the cultivars was tested according to several conditions such as growth stage of Chinse cabbage seedling, inoculum concentration, and incubation temperature after inoculation. On the basis of the results, we suggest that an efficient screening method for resistant Chinses cabbage to Pcc is to inoculate twenty one-day-old seedlings with a bacterial suspension of Pcc at a concentration of 1×10⁷ cfu/ml, and to incubate the plants in a dew chamber at 25℃ for 24 hr and then to cultivate in a growth room at 25℃ and 80% relative humidity with 12-hr light per day.

• Research in Plant Disease
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• v.20 no.4
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• pp.245-252
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• 2014

The study was performed to establish an efficient screening method for resistant cucumber to Fusarium oxysporum f. sp. cucumerinum. The isolate KR5 was identified as F. oxysporum f. sp. cucumerinum based on molecular analyses of ITS and TEF genes and host-specificity test on cucurbits including melon, oriental melon, cucumber, and watermelon. Then four cucumber and two rootstock cultivars showing different resistance degrees to the Fusarium wilt pathogen KR5 were selected. And development of Fusarium wilt of the six cultivars according to several conditions, including incubation temperature after inoculation, inoculum concentration, root wounding, and growth stages of seedlings, was investigated. Disease severity of Fusarium wilt on the resistant cultivars was changed with incubation temperatures after inoculation. The resistant cultivars showed the higher resistance when inoculated plants were kept at 25 or $30^{\circ}C$ than at $20^{\circ}C$. Among four different growth stages of the seedlings, seven-day-old seedling represented the most difference of resistance and susceptibility to Fusarium wilt. From above results, we suggest that an efficient screening method for resistant cucumber to F. oxysporum f. sp. cucumerinum is to dip the non-cut roots of seven-day-old seedlings in spore suspension of $1.0{\times}10^6-1.0{\times}10^7$ conidia/ml and to transplant the seedling into a non-infected soil, and then to incubate the inoculated plants in a growth room at $25^{\circ}C$ for 3 weeks to develop Fusarium wilt.

• Research in Plant Disease
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• v.18 no.3
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• pp.186-193
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• 2012

Biotransformation is an eco-friendly and efficient method for enhancing the bioavailability of biopesticide. To increase the antifungal activity of the crude extract of Cynanchum wilfordii roots against barely powdery mildew, we performed biotransformation of wilfoside C1G using ${\beta}$-glucosidase (cellobiase from Aspergillus niger). The mixture (G sample) of partially purified wilfoside C1G and cynauricuoside A (K1G) was treated with ${\beta}$-glucosidase to remove a glucopyranosyl moiety. The enzyme completely converted C1G to C1N and K1G to K1N. Optimal conditions for enzymatic biotransformation of G sample were determined to be 10% ethanol, 1,555 ${\mu}U$ ${\beta}$-glucosidase/ml, pH 5, and $45^{\circ}C$. In in vivo experiment, the G sample transformed by ${\beta}$-glucosidase showed stronger antifungal activity against barley powdery mildew than the non-treated G sample. These results suggest that ${\beta}$-glucosidase biotransformation can be applied to increase the antifungal activity of the crude extract of C. wilfordii roots against powdery mildews.

• The Korean Journal of Pesticide Science
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• v.8 no.2
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• pp.137-144
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• 2004

[ $\beta$ ]-Ketoacetoanilide chloride derivatives containing a substituent at 4 in phenyl group (para) reduced specifically the development of tomato late blight caused by Phytophthora infestans. Among $\beta$ketoacetoanilide chloride derivatives, five (KIST163, KIST170, KIST260, KIST263, and KIST267) were selected and tested for their protective, curative, systemic, persistent activities, and disease control efficacy against tomato late blight on adult plants. They exhibited a strong l-day protective activity and $EC_{50}$ of KIST163 and KIST170 were 21.9 and $14.5{\mu}g/mL$, respectively. However, they had little curative and systemic activities. Good persistence of KIST163 and KIST170 on tomato plants were observed against P. infestans; both KIST163 and KIST170 at $100{\mu}g/mL$ showed control values more than 75% in a 7-day protective applications. In addition, the two chemicals effectively controlled the occurrence of P. infestans on adult tomato plants. These results indicate that five $\beta$-ketoacetoanilide chloride derivatives are foliar fungicides with a preventive action and KIST163 and KIST170 have a potential for the control of tomato late blight in the fields.

• The Korean Journal of Pesticide Science
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• v.5 no.4
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• pp.33-39
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• 2001

An isolate of the indigenous fungus Pythium myriotylum was isolated from Monochoria vaginalis in Yusung, Korea in year 2000 and evaluated potential as a biocontrol agent in laboratory and greenhouse. P. myriotylum MD2 grew in a wide range of temperature regimes and the optimal growth temperature was $35^{\circ}C$. The fungus was highly pathogenic to Monochoria vaginalis at 30 to $35^{\circ}C$. Several weeds such as Rotala, indica, Lindernia procumbens, Ludwigia prostrata, Cyperus difformis, Scirpus juncoides, Aneilema keisak were also susceptible to the fungus, but Echinochloa crus-galli was not. The fungus affected the growth of rice seed germinated, but not to rice seedlings of 1- to 3-leaf stage. A total of 12 rice cultivars (3- to 4-leaf stage) tested showed no disease symptoms when inoculated with the fungus. Eleven crops, including Chinese cabbage, corn, soybean except wheat were immune to the infection of the fungi. These data suggest that P. myriotylum MD2 has a potential as a mycoherbicide to control weeds in paddy fields.