식물병연구 Note Open Access Res. Plant Dis. 22(3): 208-212 (2016) http://dx.doi.org/10.5423/rpd.2016.22.3.208 육묘상양파노균병에대한몇가지살균제의방제효과 Control Efficacy of Several Fungicides against Downy Mildew of Onion at Nursery Seedling Stage 모청용 1 ㆍ이장훈 1 ㆍ고숙주 2 ㆍ양광열 1 * 1 전남대학교농업생명과학대학식물생명공학부, 2 전라남도농업기술원 *Corresponding author Tel: +82-62-530-2076 Fax: +82-62-530-0207 E-mail: kyyang@jnu.ac.kr Chung-Yong Mo 1, Jang Hoon Lee 1, Suk-Juo Ko 2, and Kwang-Yeol Yang 1 * 1 Department of Plant Biotechnology, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Korea 2 Jeollanam-do Agricultural Research and Extension Services, Naju 58213, Korea Received June 11, 2016 Revised August 3, 2016 Accepted August 8, 2016 During the nursery seedlings stage at Muan in 2013, moisture and temperature conditions were favorable for the occurrence of onion downy mildew. Several fungicides were evaluated for controlling onion downy mildew at the stage of seedling. The disease incidence of the untreated control was 51.1%, which was sufficient to evaluate the fungicide efficacy for the control of onion downy mildew. Incidence at the mancozeb treatment (MAN treatment) was 4.4% and it was the highest control value of 91.4%. Incidence at the various fungicides treatment (MIX treatment) consisted of amectotradin plus dimethomorph, floupicolide plus propamocarb HCl, or dimethomorph plus pyraclostrobin was 10.0%, and the control value of the MIX treatment was 80.4%. Among the tested fungicides, amectotradin plus dimethomorph (AME plus DIM treatment) was selected and treated. Incidence of AME plus DIM treatment was 12.2%. There was statistically significant difference among the three different treatments and the untreated control. These results suggest that the application of fungicides on onion nursery seedlings was effective to control the onion downy mildew. Keywords: Fungicide, Nursery seedlings, Onion downy mildew, Peronospora destructor 양파에발생하는여러가지병해중에서노균병은공기 전염성병으로양파잎에피해를주어심각한수량감소를 초래하게된다. 양파노균병에의한피해는양파주산단지 에서지속적으로나타나고있으나노균병을일으키는노 균병균 (Peronospora destructor Berk.) 이활물기생균 (obligate parasite) 이어서인공배양이어려워연구가거의이루어지지 않고있으며효과적인방제방법역시확립되지않은실정 이다. 양파노균병균은수확이끝난다음토양에잠복하고 Research in Plant Disease pissn 1598-2262, eissn 2233-9191 www.online-rpd.org 있다가월동후다음해초봄에발병하여피해를주는 1차감염에따른피해와 1차감염원에서유래한분생포자에의해생육중후기에감염이지속되는 2차감염에따른피해로구분할수있다 (Choi 등, 2011: Jung, 1964). 따라서 1차피해주에서발생한분생포자의밀도가많아지면결과적으로 2차감염이심해질수있으므로 1차감염을줄이는방법이양파노균병방제에매우중요하다. 최근의양파정식시기에따른노균병 1차감염시기를연구한결과, 정식시기가빠를수록 4월상중순본밭에서조사한노균병피해주율이높게나타났으며, 특히양파정식기인 10월하순부터 11월상순에정식했을때피해주율이 38% 이 The Korean Society of Plant Pathology cc This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 208
Research in Plant Disease Vol. 22 No. 3 209 상으로높게나타나이시기에노균병 1차피해원인균이감염되었을것으로추정하였다 (Hwang 등, 2013). 이러한결과는본밭에서노균병에의한피해를최소화하기위해서는관행적으로실시하는월동후방제보다는정식전육묘부터적극적인노균병방제를수행하여 1차감염에따른병원균밀도를줄이는것이중요하다. 따라서본연구에서는노균병 1차감염시기인육묘재배기간중의발병환경조건을확인하고육묘단계에서발병을효과적으로억제하기위해등록된살균제를이용하여노균병방제효과를확인하였다. 살균제의노균병방제효과를명확하게확인하기위하여우리나라양파주요생산지역인무안군소재농가에서연작지토양을이용하여양파육묘상을설치하였다. 육묘상작업은대부분의농가에서관행적으로진행하는방법으로수행되었으며 2013년 9월 23일에파종하였다. Table 1에제시된것처럼국내에서양파노균병에등록된살균제들중에서 FRAC (Fungicide Resistance Action Committee) 목록에의거하여작용기작을고려하고육묘단계에서약해가없는살균제들을선발하여육묘상에처리하였다. 살균제의살포는파종 17일후부터 8 10일간격으로 3회처리하는것을기준으로하였고, 살균제처리는완전임의배치법 3반복으로실시하였다 (Table 2). 양파노균병균은활물기생균이므로자연발병을유도하였으며, 양파노균병조사는노균병증상이육안으로확인되는 2013년 10월 28일에각처리구간경계면 50 cm를제외하고처리구간내에서임의로 50개체를선발 한다음육안으로이병주율을조사하여다음과같은방법으로이병주율과방제가를계산하였다. 이병주율 (%)=( 처리구이병주수 / 처리구총조사주수 ) 100 처리구별방제가 (%)=(1 살균제처리구이병주율 / 무처리구이병주율 ) 100 각처리구의양파노균병방제효과의유의성검정은 IBM SPSS Statistics 20 프로그램 (IBM Co., Armonk, NY, USA) 을이용하여 Duncan의다중범위검정 P=0.05 수준에서수행하였다. 양파노균병이발병하기위해서는습도가가장중요하지만온도와햇빛역시중요한요인이다. 노균병은특히저온다습한환경조건에서발병이잘이루어지는병으로 95% 이상의상대습도가유지되면서평균기온 10 o C 12 o C가가장적합하지만약 22 o C까지는빠르게병이진전될수있다 (Hildebrand와 Sutton, 1982; Palti, 1989; Surviliene 등, 2008). 그리고노균병균의포자생존은태양일조강도와밀접한연관이있어포자를약한일조강도 (70 280 W/m 2 ) 에 6시간조사하였을때 68% 가생존하였으나중간정도의일조강도 (280 630 W/m 2 ) 와비교적강한일조강도 (630 940 W/m 2 ) 에같은시간동안조사한결과생존율이각각 5% 와 0% 로나타나약한태양일조강도가노균병진전에중요한또하나의요인이라할수있다 (Bashi와 Aylor, 1983; Palti, 1989). 따라서파종후육묘에서양파재배가이루어진 2013년 9월하순부 Table 1. List of fungicides used in this study Fungicide a.i. (%) Formulation Group name Mancozeb 75 WP Dithiocarbamates Ametoctradin+dimethomorph 27+20 SC Q I+CAA Fluopicolide+propamocarb HCl 5+50 SC Benzamide+carbamates Dimethomorph+pyraclostrobin 16+9.5 SC CAA+QoI WP, wettable powder; SC, suspension concentrate; Q I, quinone inhibitors; CAA, carboxylic acid amides; QoI, quinone outside inhibitors. Table 2. Fungicide spray schedule for the control of onion downy mildew at the stage of seedlings Treatment Spray time October 10, 2013 October 18, 2013 October 28, 2013 MAN Mancozeb Mancozeb Mancozeb AME+DIM Ametoctradin+dimethomorph Ametoctradin+dimethomorph Ametoctradin+dimethomorph MIX Ametoctradin+dimethomorph Fluopicolide+propamocarb HCl Dimethomorph+pyraclostrobin Untreated control - - - -, no spray.
210 Research in Plant Disease Vol. 22 No. 3 터정식이이루어진 11월하순까지의무안지역기상조건을확인하였다. 그러나무안지역에기상대가없는관계로무안지역에서가장가까운목포지방기상대의기상자료를확인해본결과, 2013년 9월하순부터 11월하순까지의기상조건은양파노균병발생에적합한온습도를보여주었다 (Fig. 1). 특히 10월의평균기온은 16.9 o C를기록하였으며 10월 8일부터 10월 10일까지 3일간의평균상대습도가 95.4% 를기록하였다 (Fig. 1). 그리고바닷가와가까운지형적특성상무안지역양파농가포장에서는잦은안개로인하여이른아침시간에는양파가젖어있는날이많아서제시된기상자료보다무안지역의실질적인상대습도는더높게유지되었으리라생각되었다. 또한, 잦은안개때문에태양의일조강도역시약하여육묘시기에노균병의발병및진전이이루어질수있었을것으로생각되었다. Viranyi (1974) 의연구결과에의하면, 양파노균병균포자의발아는온도와양파잎이젖어있는시간이매우중요하여적합한상대습도가유지될때 10 o C 18 o C에서 2 3시간이면포자발아가완료되고 22 o C 에서는 4시간정도가필요한반면 27 o C가되면포자발아는거의되지않는다고하였다. 그리고포자가발아하여부착기를형성하기위해서는포자발아와유사한온도조건이필요하며노균병균이양파에침입한후병징이나타날때까지의잠복기간은 10 17 일정도가소요된다 (Hildebrand 와 Sutton, 1984; Palti, 1989). 실질적으로 2013년 9월하순부터 11 월하순까지목포기상대의온도조건을살펴보면 22 o C보다높은온도를기록한날은 10월초에단이틀밖에없었다 (Fig. 1). 따라서 2013년 10월 28일에노균병을조사할때노균병초기병징을확인할수있었기때문에잠복기간을감안해보면 10월중순경에감염되었을것으로생각되었다. 이러한 결과들을종합해보면무안지역의양파농가에서육묘재배 가시작되는 9 월중 하순경부터의온도및상대습도가양파 노균병발병에적합한환경조건에해당하므로육묘에서노 균병방제에대한적극적인노력이반드시필요하리라생각 되었다. 그러나대부분의양파농가에서는월동후이듬해봄인 3 4 월경본밭에서발생하는노균병의방제를위해서는살 균제를사용하여적극적으로대처하지만육묘단계의노 균병방제필요성에대한인식이많이부족한편이다. 그 래서본연구에서양파육묘단계의노균병을방제하기위 해국내에등록되어있는살균제들을육묘에각각살포한 후양파노균병의방제효과를검정하였다. Table 3 에서확 인할수있듯이살균제가처리되지않은무처리구의이병 Table 3. Control effect of different fungicide treatments against downy mildew of onion caused by Peronospora destructor at the stage of seedlings Treatment Disease incidence (%)* Control value (%) MAN 4.4 b 91.4 AME+DIM 12.2 b 76.1 MIX 10.0 b 80.4 Untreated control 51.1 a - MAN, mancozeb; AME+DIM, ametoctradin+dimethomorph; MIX, ametoctradin+dimethomorph, fluopicolide+propamocarb HCl, dimethomorph+pyraclostrobin. *Average percentage infected onion plants for each of three replica tes. Different letters among treatments indicate the significant difference according to Duncan s multiple range tests, P=0.05. Control value (%)=(1 percentage of onion plants diseased in fungicide treatment/percentage of onion plants diseased in untreated control) 100. A Temperature ( C ) o 30 25 20 15 10 5 0 22.9 24.1 2013-09-25 2013-09-27 2013-09-29 2013-10-01 2013-10-03 2013-10-05 2013-10-07 2013-10-09 2013-10-11 2013-10-13 2013-10-15 2013-10-17 2013-10-19 2013-10-21 2013-10-23 2013 2013-10-25 2013-10-27 2013-10-29 2013-10-31 2013-11-02 2013-11-04 2013-11-06 2013-11-08 2013-11-10 2013-11-12 2013-11-14 2013-11-16 2013-11-18 2013-11-20 2013-11-22 2013-11-24 B Relative humidity (%) 100 90 80 70 60 50 40 30 20 10 0 95.5 92 98.8 2013-09-25 2013-09-27 2013-09-29 2013-10-01 2013-10-03 2013-10-05 2013-10-07 2013-10-09 2013-10-11 2013-10-13 2013-10-15 2013-10-17 2013-10-19 2013-10-21 2013-10-23 2013 2013-10-25 2013-10-27 2013-10-29 2013-10-31 2013-11-02 2013-11-04 2013-11-06 2013-11-08 2013-11-10 2013-11-12 2013-11-14 2013-11-16 2013-11-18 2013-11-20 2013-11-22 2013-11-24 Fig. 1. Temperature (A) and relative humidity (B) conditions in Mokpo area from late-september to late-november, 2013.
Research in Plant Disease Vol. 22 No. 3 211 주율이평균 51.1% 의발병률을보여처리구의살균제약효를평가하기에충분하였다. 육묘에살균제를처리한후각각의처리구에서양파노균병이발병한정도를조사한결과, 다양한작용기작을가지고있고포자발아억제효과가우수하여보호살균제로많이사용되고있는 mancozeb 을처리한 MAN 처리구에서이병주율이평균 4.4% 을보여방제가가 91.4% 로나타나방제효과가가장우수하게나타났다. 두번째로우수한효과를나타낸처리구는작용기작이각각다른살균제인 ametoctradin+dimethomorph, fluopicolide+propamocarb HCl, dimethomorph+pyraclostrobin 을순서대로살포한 MIX 처리구에서평균 10.0% 이병주율을보여방제가가 80.4% 로나타났다. 그리고살균제 ametoctradin+dimethomorph만을세차례처리한 AME+DIM 처리구에서는 12.2% 의이병주율을보여방제가가 76.1% 로나타났다. 무처리구에비해서각각의처리구에서통계적으로유의한차이를나타내었다. 본연구에서사용된살균제들은육묘에서양파노균병방제를위해서로다른작용기작을가진약제들로선발되었는데, 그중에서여러작물에서보호살균제로널리이용되고있는 mancozeb이양파노균병방제에도우수한효과가있음을확인하였다. Smith 등 (1985) 은양파노균병방제를위하여사용되는 mancozeb의잔효력을확인해보기위해 mancozeb을살포후 2, 4, 7, 10 일후에양파전체식물체와양파잎이노균병에걸린비율을조사하였고, 그결과 10일후까지도각각 25% 와 10% 만이병에걸릴정도로잔효력이유지되었다고보고하였다. 또한 Develash와 Sugha (1997) 의연구에의하면 9개의살균제를각각양파밭에살포한후노균병의방제효과를검정해본결과, 그중에서 mancozeb과 metalaxyl을혼합한살균제를 14일간격으로세차례살포하였을때양파노균병에대해 77.2% 의방제효율을보여 9개살균제중에서가장우수하였다. 본연구에서 2013년 10월 10일부터 8일과 10일간격으로세차례살포한 mancozeb 처리구가시기적으로노균병발병에적합한환경이었음도불구하고노균병발병초기에살포되어방제효과가높게나타났으며, 살균제살포기간도적절하여 mancozeb의잔효력이유지됨으로써결과적으로우수한방제효율을나타낼수있었다고생각한다. 그러나 Raziq 등 (2008) 은양파포장에서노균병을방제하기위해 10가지종류의다양한살균제효과를비교한결과에서 mancozeb과 metalaxyl을혼합한살균제처리구가 mancozeb 만을살포한처리구보다발병률이더낮게나타나가장우수한방제효과가있다고보고하였다. 따라서본연구결과를활용하여육묘단계및월동후본밭에서양파노균병의 효과적인방제를위해살균제를이용한살포체계를확립하기위해서는 mancozeb 뿐만아니라 mancozeb과 metalaxyl이혼합한살균제를이용한방제효과를검정하는연구도필요하리라생각한다. 살균제작용기작이서로다른세가지종류의살균제가교호로살포된 MIX 처리구에서도비교적높은방제효과를나타내었는데, Surviliene 등 (2008) 의연구결과에의하면다양한종류의살균제를 7 10일간격으로살포하여양파노균병방제효과를검정한결과살균제 fluopicolide+propamocarb HCl은 2005년과 2007년 2년간평균 87.99% 의우수한방제효율을나타내었다고보고하였다. 그리고최근에수행된연구에서도대조구의발병률이 67.34% 인상황에서살균제 fluopicolide+propamocarb HCl 처리구는 9.9% 의발병률을보여연구에함께사용하였던다른종류의 5개살균제에비해월등하게양파노균병의방제효과가우수하였다 (Abkhoo, 2012). 그러나 MIX 처리구에서함께사용하였던살균제 ametoctradin+dimethomorph 와 dimethomorph+pyraclostrobin에대한양파노균병방제효과를검정한연구결과가국내외적으로없고본연구에서살균제 ametoctradin+dimethomorph만을세차례살포한 AME+DIM 처리구가 MIX 처리구에비해방제효과가다소낮게나타난점으로미루어보아다양한작용기작을가진살균제를교호로살포하는것이방제효과를높이는좋은방법이라생각되었다. 노균병방제를위해개발된살균제에는특이적인작용기작을가진 quinone outside inhibitors, phenylamides, carboxylic acid amides 계통등이있으며다양한작용기작을가진살균제로는 mancozeb, chlorothalonil, copper 등이사용되고있다 (Gisi와 Sierotzki, 2008). 그러나국내에서는이러한다양한살균제를이용하여양파노균병방제를위한연구가많이진행되지않고있는실정이다. 더욱이양파육묘재배시기가노균병발병에적합한환경임에도불구하고살균제등을이용한방제가효과적으로이루어지지않는다면육묘단계에서잠복되어있던노균병균이월동한다음이듬해봄에본밭에서양파노균병을대발병하게할수있음을의미한다하겠다. 따라서육묘단계에서살균제등을사용하여양파노균병방제에대한적극적인노력이반드시필요하다고생각한다. 요약 무안지역의양파농가에서육묘재배가시작된 2013년 9 월중 하순경부터본밭에정식이이루어진 11월하순까
212 Research in Plant Disease Vol. 22 No. 3 지의온도및상대습도조건이양파노균병발병에적합한환경에해당하였다. 그래서육묘단계에서발생하는양파노균병의방제를위해살균제를이용하여연구를수행한결과, 양파육묘상에서로다른살균제들이처리된각각의처리구에비해서무처리구에서는 51.1% 의이병주율을보여살균제효과를평가하기에충분하였다. 다양한작용기작을가지고있고포자발아억제효과가우수하여보호살균제로많이사용되고있는 mancozeb을세차례살포한 MAN 처리구의이병주율이 4.4% 로나타나방제가가 91.4% 로조사되어가장우수한방제효과를보였고, 작용기작이각각다른살균제인 amectotradin+dimethomorph, fluopicolide+propamocarb HCl, dimethomorph+pyraclostrobin 을순서대로살포한 MIX 처리구는 10.0% 의이병주율을보여방제가가 80.4% 로나타났다. 그리고 amectotradin+ dimethomorph만을세차례살포한 AME+DIM 처리구는 12.2% 의이병주율을보여방제가가 76.1% 로나타나방제효과가다른두처리구에비해다소낮게나타났으나살균제가처리된모든처리구에서무처리구에비해서통계적으로유의한차이를나타내었다. 따라서양파육묘재배시기가노균병발병에적합한환경에해당되므로살균제등을사용하여육묘단계부터양파노균병방제에대한적극적인노력이필요하다고생각한다. Conflicts of Interest No potential conflict of interest relevant to this article was reported. Acknowledgement This study was financially supported by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries, the Advanced Production Technology Development Program, Ministry for Agriculture, Food and Rural Affairs, Republic of Korea. References Abkhoo, J. 2012. Efficacy of different fungicides for the control of downy mildew of onion. 1: 331. doi: 10.4172/scientificreports.331. Bashi, E. and Aylor, D. E. 1983. Survival of detached sporangia of Peronospora destructor and Peronospora tabacina. Phytopathology 73: 1135-1139. Choi, I. H., Lee, E. T., Kim, C. W. and Nam, S. S. 2011. Comparison of damage aspects of the first with the second by downy mildew disease for disease forecasting in the onion field. Korean J. Hortic. Sci. Technol. 29(Suppl II): 112-113. (Abstract) Develash, R. K. and Sugha, S. K. 1997. Management of downy mildew (Peronospora destructor) of onion (Allium cepa). Crop Prot. 16: 63-67. Gisi, U. and Sierotzki, H. 2008. Fungicide modes of action and resistance in downy mildews. Eur. J. Plant Pathol. 122: 157-167. Hildebrand, P. D. and Sutton, J. C. 1982. Weather variables in relation to an epidemic of onion downy mildew. Phytopathology 72: 219-224. Hildebrand, P. D. and Sutton, J. C. 1984. Relationships of temperature, moisture and inoculum density to the infection cycle of Peronospora destructor. Can. J. Plant Pathol. 6: 127-134. Hwang, E. J., Choi, I. H., Kwon, Y. S., Lee, E. T. and Kim, C. W. 2013. Primary infection study of downy mildew according to different times of onion (Allium cepa L.) transplants. Korean J. Hortic. Sci. Technol. 31(Suppl II): 64-65. (Abstract) Jung, B. J. 1964. Study on the control of downy mildew of onion with several new fungicides. Korean J. Plant Prot. 3: 11-14. Palti, J. 1989. Epidemiology, prediction and control of onion downy mildew caused by Peronospora destructor. Phytoparasitica 17: 31-48. Raziq, F., Alam, I., Naz, I. and Khan, H. 2008. Evaluation of fungicides for controlling downy mildew of onion under field conditions. Sarhad J. Agric. 24: 85-91. Smith, R. W., Lorbeer, J. W. and Abd-Elrazik, A. A. 1985. Reappearance and control of onion downy mildew epidemics in New York. Plant Dis. 69: 703-706. Surviliene, E., Valuskaite, A. and Raudonis, L. 2008. The effect of fungicides on the development of downy mildew of onions. Zemdirbyste 95: 171-179. Viranyi, F. 1974. Studies on the biology and ecology of onion downy mildew (Peronospora destructor (Berk.) Fries) in Hungary. II. Factors influencing sporulation and conidium germination. Acta Phytopathol. Acad. Sci. Hung. 9: 315-318.