Background : This study was conducted to investigate the resistance of Collectotrichum gloeosporioides to 9 fungicides. Methods and Results : With 3 isolates of Collectotrichum gloeosporioides obtained from diseased leaf of ginseng, it was conducted to detect the fungicide resistance of C. gloeosporioides against 9 chemicals through an agar dilution method. PDA medium was used for monitoring the resistance. Among the chemicals, fenhexamid・prochloraz manganese complex, fluazinam and metconazole exhibited high antifungal activity to the ginseng anthracnose fungus. When measuring the effectiveness for the prevention of anthracnose, 3 fungicides at 10 ㎍/㎖ showed 88.1 - 94.7% of preventive effect against C. gloeosporioides. But, the isolates resist to dimethomorph・dithianon, iminoctadine tris (albesilate), kasugamyci n・thiophanate-methyl, dimethomorph・pyraclostrobin, azoxystrobin. Conclusion : In summary, to develop the control system with fungicides, 3 fungicides (fenhexamid・prochloraz manganese complex, fluazinam and metconazole) were applied on ginseng at the indicated time. A reduced spray program based on efficacious fungicides will be useful for ginseng growers and provide more options for controlling anthracnose in Korea.

Background : Among registered fungicides for controlling ginseng disease, the disease occurrence rate from the mixed use of a single ingredient, mancozeb WP, and copper sulfate basic WP was examined, and experiments were conducted to establish safe disease control system. Methods and Results : As for the medicines used for the experiments, besides registered Pyraclostrobin WG as a single ingredient for ginseng disease control, 14 kinds were used for experiments. The fungicide was sprayed 5 times on June 21, July 4, July 16, August 2 and August 24. The examination was conducted 5 days, 10 days, 15 days, and 20 days after the final fungicide treatment. Anthracnose occurrence rate 5 days after the final fungicide treatment was 0.0 - 61.3% which was different depending on fungicides, and in a single treatment, the occurrence rate was less than 1% in 6 fungicides. In the single treatment, the occurrence rate was more than 1%, but 9 kinds of fungicides which had less than 1% occurrence rate in the case of mixed use with mancozeb, and one kind in the case of mixed use with copper sulfate basic 10 days later, the occurrence rate was 0.0 - 100% and there were lots of differences in the disease occurrence rate depending on fungicides. 10 kinds of fungicides showed the disease occurrence rate of more than 10.0% in the case of a single treatment. Among them, 9 fungicides showed the disease occurrence rate of less than 1.0% in the case of mixed use with mancozeb, indicating the effect of lowering disease occurrence rate in the case of mixed use. 15 days later, 9 fungicides showed disease occurrence rate of more than 2%, 1 kind of fungicide had the disease occurrence rate of less than 1%, and the overall disease occurrence rate increased. Among them, 7 kinds of fungicides showed the disease occurrence rate of less than 1% from the mixed use. 20 days later, 12 kinds of fungicides showed the disease occurrence rate of more than 50%, and only 1 kind of fungicide showed the disease occurrence rate of less than 1%. In the case of mixed use with mancozeb, 2 kinds had the disease occurrence rate of less than 10% and 1 kind of fungicide had the disease occurrence rate of less than 1%. Conclusion : For prevention of anthracnose disease of ginsengs during a rainy season, the disease occurrence rate from a single or mixed use was examined, and the examination found that rather than a single use, mixed use decreased the disease occurrence rate. In particular, the mixed use with mancozeb showed low disease occurrence rate and prevented the disease occurrence rate for a long time.

Background : The dried ripe fruits, leaf and root of boxthorn are widely used for medicinal purposes and as a functional food. Among them, frut is the most susceptible to anthracnose in the open field. Currently, there are only 5 fungicides registered in boxthorn anthracnose. In addition, resistance to fungicides caused by frequent use occurred in many open field, Therefore, a study on the fungicide resistance of boxthorn anthracnose was needed. Methods and Results : In 2017, collected anthracnose from boxthorn fruit. The collected samples were isolated by a single spore isolation method and 20 isolates of Collectotrichum spp. were obtained To test for anthracnose fungicide resistance, propineb, tebuconazole, azoxystrobin and pyraclostrobin fungicide were used. Monitoring for fungicide resistance of Collectotrichum spp. causing boxthorn anthracnos to test fungicide were conducted by agar dilution method. The assay concentration were control, 0.01, 0.1, 1, 10, 100 ㎍/㎖ and strobilurin group of azoxystrobin and pyraclostrobin were treated salicylhydroxamic acid (SHAM) to the alternative breath suppression at a concentration of 100 ㎍/㎖. In the result, Prevention of fungicide propineb was more than 100 ㎍/㎖ of EC50, and tebuconazole was less than 1 ㎍/㎖ except for 1 isolate of EC50 azoxystrobin and pyraclostrobin showed a difference even though they had the same mode of action. Azoxystrobin showed almost no inhibition of mycelial growth except 6 isolates and remaining 6 isolates had EC50 of less than 1 ㎍/㎖, pyraclostrobin was divided into two groups of EC50, 6 isolates were less than 0.1 ㎍ /㎖ and 14 isolates were more than 1 ㎍/㎖. Conclusion : In summary, response to fungicides of anthracnose, azoxystrobin of strobilurin group showed the highest resistance to fungicide. As these fungicide resistance continues to develop, we plan to register a new anthracnose fungicide and improve the control method.

This study was investigated the effects of various commercial sanitizers on microbial characteristics in fresh-cut iceberg lettuce during storage. For screening sanitizer, lettuce was cut and dipped in chlorine water (0.2 ml·L-1), solution of organic acids such as ascorbic acid, citric acid, acetic acid, mixture of ascorbic acid and acetic acid (1-6%), and solutions of commercial sanitizers such as Formula 4TM (1,3,4%), Fresh produce washTM (1,3,4%), CleancolTM (1%), ChitocholTM (1%) and Natural CaTM (0.1%) for 3 min, respectively. Washing lettuce with selected sanitizers resulted in reduction of aerobic bacteria of more than 2 log CFU/g. Initial pH of lettuce was related with the pH of sanitizers. pH ranged from 4.7 to 6.1 in Formula 4 (4%, pH 1.7) and Natural Ca (0.1%, pH 12.0), respectively. Chlorine water showed consistent and significant inhibition effect in all of microorganisms except total coliform. Over 3% of Formula 4 and Fresh produce wash were found to have high bactericidal activity among sanitizers. The sanitizers of chlorine water, Fresh produce wash, Chitochol and Natural Ca were effective in reducing yeast and mould populations. As coliform and E. coli, Formula 4 (4%) showed the highest bactericidal activity. The bactericidal effect of commercial sanitizers during storage varied with the kinds and concentrations of tested sanitizers. Although inhibition effect was not showed during storage, these results suggest that commercial sanitizers could be an alternative to chlorine for washing fresh-cut produce.

The aim of this work is to assess the safety of fungicide tolclofos-methyl, difenoconazole and azoxystrobin in ginseng sprayed by safe use guideline. When tolclofos-methyl was sprayed on ginseng by safe use guideline, the residue amounts (MRL) of it in ginseng was 0.13 mg/kg which is below than 0.3 mg/kg, maximum residue limit established by Korea Food & Drug Administration (KFDA). The residue amounts of ginseng parts, head part was 0.37 mg/kg and main body part was 0.13 mg/kg. In case of difenoconazole, the residue amounts in ginseng was 0.81 mg/kg. which was exceed the MRL, 0.2 mg/kg. By the analyze results of ginseng part, the residues of head and main body part were 3.01 and 0.40 mg/kg, respectively. In experiment of vinyl mulching, the residue amount of difenoconazole in ginseng was 0.05 mg/kg. The residue amounts of azoxystrobin in ginseng sprayed by safe use guideline was 0.14 mg/kg. This residue was not exceed the MRL 0.5 mg/kg. The residue amounts by ginseng parts was 0.51 mg/kg for head part and 0.28 mg/kg for main body part. In case of vinyl mulching, the residue amount of azoxystrobin was 0.02 mg/kg.

수도기계이앙재배를 위한 상자육묘에 있어서 발생하기 쉬운 입고병이나 생리적 장해인 뜸묘를 방지하기 위한 예방적 기술대책으로서 3-Hydroxy-5-methylisoxazole(상품명 : 다찌가렌)을 비롯한 채소의 로균병방제약제인 SF 8002와 벼의 도열병방제약제인 Isoprothiolane(상품명 : 후지왕)등을 상토 또는 육묘중에 처리함으로서 입고병과 뜸묘의 발생억제효과와 함께, 이들 약효가 묘의 생육과 생리적 활력 증대(건묘육성)에 미치는 영향을 연구 검토한 바 그 결과를 요약하면 다음과 같다. 1. 묘의 지상부를 절단하고 뿌리로부터 흡수된 수분이 야간에 엽초부에 있는 통도조직을 통해서 절단부에 맺치는 일필량의 다소로서 뿌리의 생리적 활력을 진단한 바 Hydroxyisoxazole 19%, SF 8002 24%, Isoprothiolane 35%, Metalayl 41%의 순으로 일필량이 많았다. 2. 20일묘의 뿌리를 절제 사경재배조건에 삽식하여 활착과 관련이 있는 신근발생량을 보면 약제처리에 의한 신근의 발근력이 크게 증가하였으며, 신근발근력과 일필량간에는 고도의 정의 유의상관 관계를 인정할 수 있었다. 3. 35일묘를 대상으로 묘를 뽑아 수평으로 높이고 뿌리를 포수상태로 흡수시키면서 지상부의 굴기력을 측정한 바, 공시약제간 차이는 있으나 무처리에 비해 현저히 빠른 것으로 보아 이들 약제처리에 의한 묘의 활착력이 크게 증대됨을 확인할 수 있다. 4. 광합성능력과 직접 관계가 깊은 기공의 개도에 의한 절단한 지상부의 수분감소율의 추이를 보면 Hydroxyisoxazole 및 SF 8002 처리구가 다같이 수분감소율이 큰 것으로 보아 생리활성의 증대가 큰 것으로 해석되었다. 5. 파종후 20일묘를 립모상태하에서 지상부를 절단한 후 지상부의 재생능력을 보면 Isoprothiolane을 제외한 다른 약제처리에서 다같이 높았으며, 특히 SF 8002 및 Metalaxyl이 현저하였다. 6. 이들 살균제처리구는 묘의 생리적 장해인 뜸묘의 방제효과가 뚜렷하였으며, 이같은 효과는 앞에서 지적한 바와 같이 이들 약제가 가지는 생육조절작용으로서의 생리적 활력 증대가 뜸묘의 발생을 예방적으로 방제하는 간접효과라고 해석된다.