제 3발표장 ( 토양유기물 , 미생물 ) / 감귤원 토양의 표토관리 방법에 따른 미생물상조사

좌재호,임한철,이종희,한승갑,현태남 한국토양비료학회 1999 한국토양비료학회 학술발표회 Vol.1999 No.61

화산회토양에서 분리한 인산 가용화균의 배양특성 및 난용성 인산염의 가용화

좌재호,임한철,고상욱,한승갑,이종희 한국토양비료학회 2001 한국토양비료학회 학술발표회 Vol.2001 No.-

망고, 용과, 아티초크에 발생하는 주요 병해 증상

좌재호,명인식,정봉남,고상욱 한국농약과학회 2016 한국농약과학회 학술발표대회 논문집 Vol.2016 No.4

Fusarium oxysporum에 의한 패션프루트 시들음병

좌재호,최인영,최민경,허병수,장종옥,신현동 한국식물병리학회 2018 식물병연구 Vol.24 No.1

From 2014 to 2016, Fusarium wilt disease was found on fassionfruit in Iksan and Jeju, Korea. Symptoms included wilting of foliage, drying and withering of leaves, and stunting of the plants. The infected plants eventually died during growth. Colonies on potato dextrose agar were pinkish white, and felted with cottony and aerial mycelia with 35 mm after one week. Macroconidia were falcate to almost straight, thin-walled and usually 2-3 septate. Microconidia were usually formed on monophialides of the hyphae and were hyaline, smooth, oval to ellipsoidal, aseptate or medianly 1-septate, very occasionally 2-septate, slightly constricted at the septa, 3-12 × 2.5-6 mm. On the basis of the morphological characteristics and phylogenetic analyses of two molecular markers, internal transcribed spacer rDNA and translation elongation factor 1α, the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was proved by artificial inoculation, fulfilling Koch’s postulates. To our knowledge, this is the first report on the occurrence of F. oxysporum on fassionfruit in Korea. 2014년부터 2016년까지 전라북도농업기술원(익산)과 국립원예특작과학원 온난화대응농업연구소(제주)에서 패션프루트 시들음병이 관찰되었다. 병징은 생육 초기 건전주에 비해 생육이 더디고새순부터 시듦 증상이 나타나기 시작하였으며, 오래된 잎은 마르고 뒤틀리다가 더 이상 생육하지 않고 말라 죽었다. 감자한천배지에서 균사 생육은 직경이 35 mm/7일이었으며, 핑크빛-흰색으로양모상이었다. 병원균의 대형분생포자는 무색으로 투명하며, 길이가 짧고 굴곡진 모양-일자형으로 세포벽이 얇고 주로 2-3개의격벽이 있었다. 소형분생포자는 균사로부터 monophialides 위에형성되었으며, 투명하고, 난형-타원형이며, 격벽이 없거나 1개인데, 드물게 2개인 경우도 있었고, 크기는 3-12×2.5-6 μm이다. 균학적 특징, 병원성 검정, ITS rDNA, EF-1α 염기서열 비교분석 등의결과를 바탕으로 이 병은 우리나라에서 지금까지 보고되지 않은Fusarium oxysporum에 의한 ‘패션프루트 시들음병’으로 명명하고자 한다.

토양개량제시용에 따른 화산회토양 감자 연작지 더뎅이병 억제 효과

좌재호,문두경,고상욱,손다니엘,Joa, Jae-Ho,Moon, Doo-Kyung,Koh, Sang-Wook,Son, Daniel 한국유기농업학회 2014 韓國有機農業學會誌 Vol.22 No.4

This study was conducted to select proper soil amendments in order to reduce the occurrence of potato scab and maintaining soil health by applications of dolomitic lime, sulfur, potassium sulfate, shell meal fertilizer, silicate fertilizer, lime nitrogen and ammonium sulfate fertilizer in different pH levels of volcanic ash soil with continuous cultivation of potato. In potassium sulfate-applied plot with a low soil pH, the incidence rate and disease severity of scab were lowest at 84.4% and 28.4%, respectively. Those were lowest among the treatments. Value of potato scab control was 12.3% and marketable yield of potato was highest at 93.2%. In lime nitrogen-applied plot (60 kg/10a), the incidence rate was low at 38.3%, and control value was 23.8% and marketable yield of potato was high at 66.3%. In relatively higher pH soils, the incidence rate of scab was lowest at 38.3% in the lime nitrogen-applied plot (60 kg/10a). Value of potato scab control was 23.8%, which was four times higher than that in sulfur-applied plot. Marketable yield of potato was highest at 66.3% in the lime nitrogen-applied plot. In the lime nitrogen plot infected with potato scab pathogen such as S. acidiscabies and S. scabiei were remarkably lower than other soil amendments at 2.5, 5, and 10 g/L concentrations of lime nitrogen using Glucose Yeast Malt (GYM) medium. In conclusion, this study suggests that potassium sulfate application in low pH soil (less than pH 5) and lime nitrogen application in relatively higher pH soil (more than pH 6) before potato seeding might be helpful to reduce the occurrence of potato scab. 화산회토양 감자 연작지 토양 pH 수준별로 고토석회, 유황, 황산칼륨, 패화석, 규산질비료, 석회질소, 유안비료를 이용하여 감자 더뎅이병 발생을 경감시키고 토양건전성을 유지하는데 적절한 대체농자재를 선발하고자 수행하였다. 토양 pH가 낮은 황산칼륨 처리구(24 kg/10a)에서는 더뎅이병 발병률이 84.4%, 발병도가 28.4%로 가장 낮았다. 방제효과는 12.3%, 상품율은 93.2%로 다른 처리구와 비교할 때 가장 높게 나타났다. 석회질소 처리구(60kg/10a)가 발병도 38.3%로 낮았고 방제효과 23.8%, 상품율 66.3%로 높았다. 토양 pH가 높은 시험구 중 더뎅이병 발병률은 석회질소 처리구(60 kg/10a)가 38.3%로 가장 낮았고 유안 처리구(48 kg/10a)는 62.6%로 높았다. 더뎅이병 방제효과는 석회질소 처리구(60 kg/10a)에서 23.8%로 유황 처리구의 6.1% 보다 4배 이상, 상품률은 66.3%로 가장 높게 나타났다. 감자더뎅이병 병원균 Streptomyces acidiscabies과 Streptomyces scabiei를 석회질소 2.5, 5 g/L, 10 g/L에 접종시 생장량은 다른 토양개량제 보다 상대적으로 억제되었다. 결론적으로 감자 파종 전에 토양 pH가 5 이하이면 황산칼륨을, 6 이상이면 석회질소를 시비하면 더뎅이병 발생을 경감시킬 수 있을 것으로 보인다.

Effect of Long-Term Different Fertilization on Bacterial Community Structures and Diversity in Citrus Orchard Soil of Volcanic Ash

좌재호,원항연,현해남,전용철,고상욱 한국미생물학회 2014 The journal of microbiology Vol.52 No.12

This study was conducted to assess bacterial species richness,diversity and community distribution according to differentfertilization regimes for 16 years in citrus orchard soil of volcanicash. Soil samples were collected and analyzed fromCompost (cattle manure, 2,000 kg/10a), 1/2 NPK+compost(14-20-14+2,000 kg/10a), NPK+compost (28-40-28+2,000kg/10a), NPK (28-40-28 kg/10a), 3 NPK (84-120-84 kg/10a),and Control (no fertilization) plot which have been managedin the same manners with compost and different amount ofchemical fertilization. The range of pyrosequencing readsand OTUs were 4,687–7,330 and 1,790–3,695, respectively. Species richness estimates such as Ace, Chao1, and Shannonindex were higher in 1/2 NPK+compost than other treatments,which were 15,202, 9,112, 7.7, respectively. Dominantbacterial groups at level of phylum were Proteobacteria, Acidobacteria,and Actinobacteria. Those were occupied at 70.9%in 1/2 NPK+compost. Dominant bacterial groups at levelof genus were Pseudolabrys, Bradyrhizobium, and Acidobacteria. Those were distributed at 14.4% of a total of bacteriain Compost. Soil pH displayed significantly closely relatedto bacterial species richness estimates such as Ace, Chao1(p<0.05) and Shannon index (p<0.01). However, it showedthe negative correlation with exchangeable aluminum contents(p<0.05). In conclusion, diversity of bacterial communityin citrus orchard soil was affected by fertilization management,soil pH changes and characteristics of volcanic ash.

유기물 연용이 감자재배 비화산회토양의 화학성과 효소활성에 미치는 영향

좌재호,문경환,서형호,최경산,김성철 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.5

This study was carried out to evaluate effect of consecutive application of organic matter on soil chemical properties and dehydrogenase, acid phosphatase activity in non-volcanic ash soil during three cropping season. Organic matter mixture and organic fertilizer (MOF, 2,000 kg 10a^-1), food waste compost (FWC,2,000 kg 10a^-1), and pig manure compost (PMC, 2,000, 4,000, and 6,000 kg 10a^-1) were applied for each cropping season. Soil pH values were increased after three cropping season in all treatment. In the soils of the increased application of PMC, soil pH, total-nitrogen, available phosphate, exchangeable cations (K, Ca, and Mg), and heavy metal (Zn and Cu) contents were increased. In addition, Soil dehydrogenase activity was significantly increased in proportions to PMC application rate and cropping season during potato cultivation period. The activity was two times higher in PMC (4,000 kg 10a^-1) than control after the third cropping season. Soil dehydrogenase activity was in order of PMC>FWC>NPK+PMC>MOF. Acid phosphatase activity was higher in PMC (6,000 kg 10a^-1) than other treatment. Soil Zn content and dehydrogenase activity showed linearly correlation, which were MOF (R2=0.427), FWC (R2=0.427) and PMC (R2=0.411, p<0.01),respectively. This study demonstrated that soil chemical properties and enzyme activity could be affected greatly by consecutive application of different organic matter in the potato cultivation field.

제주지역 키위(참다래) 궤양병 발생 현황

좌재호,명인식,정봉남,박교선 한국농약과학회 2015 한국농약과학회 학술발표대회 논문집 Vol.2015 No.10

미세살수와 탄산칼슘 및 카올린 엽면살포가 온주밀감의 일소 발생과 과실 품질에 미치는 영향

좌재호,강석범,박요섭,김미선,김하늘,오복심,Joa, Jae-Ho,Kang, Seok-Beom,Park, Yo-Sup,Kim, Mi-Sun,Kim, Ha-Neul,Oh, Bok-Shim 한국생물환경조절학회 2022 생물환경조절학회지 Vol.31 No.4

본 연구는 '암기조생' 감귤 과실의 표면온도와 일사량 간의 상관관계를 분석하여 일소가 유발되는 과실 표면온도를 예측하고 일소 발생을 경감시키고자 수행하였다. 이를 위해 기온이 31℃일 때 30분 간격으로 5분 미세살수와 1% 탄산칼슘, 4% 카올린 용액을 10일 간격으로 3회 엽면살포하여 일소과 발생과 과실 품질을 조사하였다. 과실 표면온도는 일사량과 R = 0.788(p < 0.01)로 유의한 정의 상관관계를 나타냈으며 한낮에는 기온보다 최고 16℃가 높았다. 과실 표면온도를 추정하는 회귀식 y = 0.099 × (대기온도) + 0.018 × (일사량) + 20.779(R = 0.687, p < 0.01)을도출하였다. 30분 간격으로 5분 미세살수시수관 내부 온도가 무처리보다 5.1℃ 낮았다. 일소과 발생률은 미세살수구가 2.1%로 무처리구보다 2배 이상 낮았고 통계적으로 유의성을 나타냈으나, 과실 품질은 처리간에 비슷하였다. 햇빛을 반사하거나 미세살수를 실시하여 과실 표면온도를 낮추면 일소 발생을 줄일 수 있을 것으로 보인다. This study was carried out to predict fruit surface temperature (FST) causing sunburn symptoms and assess the correlation between solar radiation and FST in satusma mandarin (Citrus unshiu Marc. 'Iwasaki'). And to reduce sunburn when ambient temperature was at 31℃, sprinkler system was repeated spraying every at 5 minutes of 30 minutes intervals and 1% calcium carbonate and 4% kaolin solution applied on citrus tree three times to investigate quality and sunburn of fruits. It showed highly significant positive correlation between FST and solar radiation (R = 0.788, p < 0.01), The FST increased up to 16℃ than ambient temperature at daytime. To estimate FST, a linear model y = 0.099 × (air temperature) + 0.018 × (solar radiation) + 20.779 (R = 0.687, p < 0.01) was derived. The canopy temperature of citrus trees was 5.1℃ lower in sprinkler system than in control. The incidence of sunburn showed at 2.1% in sprinkler system twice lower than in control and there was different significance. Fruit quality was similar between treatments. In conclusion, sunburn can be reduced by reflecting sunlight or downing of FST through sprinkler system.

수관 피복이 노지재배 '부지화' 감귤나무의 보온과 내한성에 미치는 영향

좌재호,강석범,문영일,이혜진,Joa, Jae-Ho,Kang, Seok-Beom,Moon, Young-Eel,Lee, Hae-Jin 한국생물환경조절학회 2021 생물환경조절학회지 Vol.30 No.4

노지재배 '부지화' 나무의 동해를 경감시키기 위해 피복재로 타이벡, 위드스톱, 35% 차광망을 사용하여 피복재 내, 외부 온도와 상대습도 변화를 평가하였다. 한파 시 피복에 따른 보온 정도와 잎의 LT₅₀을 조사하였다. 타이벡은 1.5m에서 피복재 내부와 외부의 온도 차이는 낮았고 0.4m에서는 높았다. 상대습도는 주야간 차이가 컸으며 오전 6-8시에 높았다.-2℃일 때 24시간 타이벡 피복은 수관 1.5m에서 무처리보다 적산온도가 3.4℃ 높았다. 잎의 LT₅₀은 타이벡 1.51℃, 위드스톱 1.33℃, 35% 차광망은 1.61℃로 무처리보다 낮았다. 타이벡의 수관 내 보온효과와 상대습도를 고려할 때 환기를 위한 미세한 천공 후 '부지화' 나무에 피복시 동해 발생을 줄일 수 있을 것으로 보인다. It were investigated changes in internal and external temperature, relative humidity using tyvek, weedstop, and 35% shading net as covering material to reduce the freezing damage of 'Shiranui' hybrid mandarin grown in open field. It were also evaluated canopy covering effect and LT₅₀ of leaves by covering material when it was cold at -2℃. In tyvek, temperature difference between inside and outside was low at the height of 1.5m and was high at 0.4m. The relative humidity differed greatly between day and night, and was high at 6-8 a.m. At -2℃, Sum of temperature at the height of 1.5m of canopy for 24-hour after covering were at 3.4℃ higher in tyvek than in control. The LT₅₀ of leaves was at 1.51℃ in tyvek, 1.33℃ in withstop, and 1.61℃ in 35% shading net lower than in control. Considering thermal insulation and relative humidity in canopy, tyvek is expected to reduce low temperature damage when covering after making a fine hole for ventilation.