• Title/Summary/Keyword: Leaf blight disease

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The Study on the Effect to the Yields with the Intermediate Cutting Periods of Mulberry Branch and at the Picking Levels of Leaf Remains in Autumn (추잠기 중간벌채시기 및 잔조에서의 적엽정도가 뽕의 수량에 미치는 영향에 관한 연구)

  • 김문협;김호락;최하자
    • Journal of Sericultural and Entomological Science
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    • v.13 no.2
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    • pp.81-94
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    • 1971
  • This research is conducted to study the effect to rebbuding, death atop, yielding and occurrence of twig blight disease with the interemediate cutting periods of mulberry branch and at the picking levels of leaf remains in autumn. The results obtained are as follows: 1. Re-budding branches are decreased with delaying of interval cutting period, and that more leaves remained lesser both re-budding branches and buds are observed. Therefore, it is better that leaves remained are placed on the upper part of branch, practically with 3-5 leaf remains. It has decreased re-budding branches, in case cutting is conducted in Sept. 20 with picking leaving 3-5 leaf on. 2. With regard that all picking increases the percentage of death atop of the branch and upper half part picking increases slightly over the other treats. Although it seems unlikely to be different in the other treats with cutting period, exception of all picking, it is elucidated better that the all picking after cutting in Sept. 15 represents unusually high, seemingly effected by the temperature contition preferable to the life of twig blight disease along with the lack of branch nutrition caused by the all picking. 3. In view of yielding, it has no difference in autumn yielding with cutting period, but more picking levels of leaf remains, more yielding. In spring yield, both no picking and all picking is the lowest, in spite of cutting period. Each treat produces high yielding except the no picking if rutting is done in Sept. 15 and Sept. 20, respectively; otherwise it is done earlier or later, each treat produces low yielding. It is suggested that yielding ability in following spring affected by the autumn picking because all picking treats represent lower yielding ability than no picking ones except of cutting in Sept. 15 and Sept. 20. With respect to total yield in spring and autumn, it is represented that other treats, among which cutting in Sept. 15 and Sept. 20 is especially high, produce higher yielding than both no picking and all picking. But no difference seemed in leaf remained treats. In these respects, it may be concluded that 3-5 leaf remains after the interval cutting in Sept. 15 to Sept. 20 increases the yielding throughout two seasons and it is suggested that 3-5 leaf remains after cutting in Sept. 5 to Sept. 10 has no difference with no picking and cutting after that day. 4. Diseases in the branch remained are twig blight, massaria-bye, and Die-back, of which twig blight attacks tremendously and slight ouurence in messaria-byo and Die-back. In ouurence of twig blight, it is appeared much in all picking and seasonal occurence high in Sept. 15 with 92.9, and in Sept. 30 with 100 as index, respectively. Also it occurs ,considerably in upper part picking but little occurrence in no picing. 5. It is considered that negative correlation among re-budding percentage. No. of re-budding leaf, and spring yielding is found, seemingly without heavy correlation at -0.42, and -0.27, respectively. However, death atop of branch and occurence of twig blight has little correlation with spring yield. On the other hand, positive correlation highly appeared with the correlation coefficient at 0.8 between occurence of twig blight and death atop of branch.

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Halo Blight of Kudzu Vine Caused by Pseudomonas syringae pv. phaseolicola in Korea

  • Jeon, Yong-Ho;Chang, Sung-Pae;Kim, Sang-Gyu;Kim, Young-Ho
    • The Plant Pathology Journal
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    • v.22 no.2
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    • pp.119-124
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    • 2006
  • Kudzu vine(Pueraria montana var. lobata) is an invasive climbing woody vine that envelops trees and shrubs, pressing physically and shutting out sunlight, which needs to be controlled. Kudzu vine pathogens were surveyed as a way to seek its biocontrol agents in 2002. Occurrence of a bacterial halo blight disease of kudzu vine was observed at several localities in Korea including Euiwang and Suwon in Gyeonggi Province, Daejon, and Gochang and Buan in Jeonbuk Province. Symptoms of brown to black spots with a surrounding yellowish halo appeared from June and lasted till the rainy season without much expansion, but accompanying often leaf blight and defoliation. Isolated bacteria were identified as Pseudomonas syringae pv. phaseolicola based on physiological and cultural characteristics, Biolog, fatty acid and 16S rDNA sequencing analyses. In artificial inoculation test, these bacteria produced the same halo spot symptoms on kudzu vine and bean plants. They also induced hypersensitive responses (HR) on tobacco, tomato, and chili pepper leaves. This is the first report of a bacterial disease of kudzu vine in Korea, and the bacterial pathogen can be used as a biocontrol agent against the pest plant.

Grovesinia moricola occurring on Parthenocissus tricuspidata

  • Shin, Hyeon-Dong;Choi, Young-Joon;Hong, Sun-Hee;Lee, Yong-Ho
    • The Korean Journal of Mycology
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    • v.47 no.3
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    • pp.271-274
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    • 2019
  • Between August and September 2017, zonate leaf spots with severe defoliation were observed on Parthenocissus tricuspidata in Gimcheon, Korea. The initial symptoms included water-soaked, gray to grayish brown, circular or irregular-shaped leaf spots. As the disease progressed, the spots enlarged, coalesced, and became cream-colored with characteristic target-shaped rings, leading to leaf blight and premature defoliation. Based on cultural and morphological characteristics, the fungus associated with the symptoms was identified as Grovesinia moricola. The identity of this fungus was confirmed by analyzing sequences of the internal transcribed spacer region of ribosomal DNA. The pathogenicity of the isolate was demonstrated by artificial inoculation. To our knowledge, this is the first report of G. moricola occurring on P. tricuspidata globally as well as in Korea.

An Analysis of Impacts of Climate Change on Rice Damage Occurrence by Insect Pests and Disease (기후변화가 벼 병해충 피해면적 발생에 미치는 영향분석)

  • Jeong, Hak-Kyun;Kim, Chang-Gil;Moon, Dong-Hyun
    • Korean Journal of Environmental Agriculture
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    • v.33 no.1
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    • pp.52-56
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    • 2014
  • BACKGROUND: It is known that impacts of climate change on damage occurrence by insect pests and diseases are increasing. The negative effects of climate change on production will threaten our food security. It is needed that on the basis of analysis of the impacts, proper strategies in response to climate change are developed. METHODS AND RESULTS: The objective of this paper is to estimate impacts of climate change on rice damage occurrence by insect pests and diseases, using the panal model which analyzes both cross-section data and time series data. The result of an analysis on impacts of climate change on rice damage occurrence by pest insect and disease showed that the damage occurrence by Rice leaf roller and Rice water weevil increased if temperature increased, and damage occurrence by Stripe, Sheath blight, and Leaf Blast increased if precipitation(or amount of sunshine) increased(or decreased). CONCLUSION: Adaptation strategies, supplying weather forecasting information by region, developing systematical strategies for prevention of damage occurrence by pest insect and disease, analyzing the factors of damage occurrence by unexpected pest insect and disease, enforcing international cooperation for prevention of damage occurrence are needed to minimize the impacts of damage occurrence on rice production.

Combined Treatment with Gamma Irradiation and Sodium Dichloroisocyanurate to Control Leaf Blight and to Preserve Cut Lilies (절화 백합 잎마름병 방제 및 품질 보존을 위한 감마선 150 Gy와 Sodium Dichloroisocyanurate 병용처리)

  • Koo, Tae-Hoon;Hong, Sung-Jun;Yun, Sung-Chul
    • Research in Plant Disease
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    • v.22 no.2
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    • pp.94-99
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    • 2016
  • For the purpose of practical application of gamma irradiation for export lily without the ionic energy damage, 150 Gy gamma ray was suggested as the safe level on cut lilies, the oriental cultivar Siberia (white) and Sorbonne (pink). The combined treatments of 150 Gy gamma ray and sodium dichloroisocyanurate (NaDCC) at 0, 40, 100, and $200{\mu}g/l$, were tried to control lily leaf blight caused by Botrytis elliptica. Incidences of petal blight on the two oriental lilies at control were 93%-95%, whereas those at the combined treatments of 150 Gy and $100{\mu}g/l$ or higher of NaDCC were 76%-83%. However, severity of petal blight was not reduced by the combined treatments. Gamma irradiation at 150 Gy did not change the cut lily quality such as improve cut lily longevity of vase-life compare with the control. In addition, fresh weight, chlorophyll contents, and the color of pink petals of Sorbonne were not changed by 150 Gy of gamma irradiation. Therefore, we recommend the combined treatment of 150 Gy gamma irradiation and $100{\mu}g/l$ NaDCC for the standard operating procedure on cut lily for export quarantine to control leaf blight.

Controlling Effect of Some Environmentally Friendly Agents on Garlic Leaf Blight in Garlic (마늘 잎마름병에 대한 친환경제제 방제효과)

  • Ryu, Young-Hyun;Huh, Chang-Seok;Kim, Dong-Geun;Yeon, Il-Kwon;Jo, Woo-Sik;Ryu, Jung-A
    • Korean Journal of Organic Agriculture
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    • v.23 no.2
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    • pp.347-357
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    • 2015
  • This experiment was conducted to test the efficiency of environmentally friendly materials for controlling garlic leaf blight by Stemphylium botryosum. Fifty five kinds of environmental friendly control agents are obtained from commercial market and are tested for spore germination using 96 well plate and among them, five agents (copper-, sulfur-, medinal herb extract-, sulfur+sodium bicarbonate- and oligo chitosan based compound) are selected for field test from 2012 and 2013 year. With reference of 2012 year test result, copper and oligo chitosan based compounds are chosen as 2013 year test. When the first symptoms were appeared early May season and environmental friendly control agents are applied as prompt as possible, the control value of copper and oligo chitosan based agents are 54% and 90% respectively as compared to the occasion of chemical agent Antracol WP (propineb 70%) and yield of bulbs are increased by 16% and 34% against untreated control and marketable garlic bulb yield were 79% and 95% against Antracol WP treatment, respectively. From this result, oligo chitosan based compound can be a good organic control agent candidate for garlic leaf blight disease in organic garlic cultivation.

Isolation and Identification of Myxobacteria KR025 and Searching of Their Bioactive Compounds (점액세균 KR025의 분리 동정 및 생리활성물질의 탐색)

  • 김병섭;안종웅;조광연
    • Korean Journal Plant Pathology
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    • v.14 no.4
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    • pp.345-349
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    • 1998
  • Fifty isolates of myxobacteria were isolated from soils from several areas in Korea during 1996-1997 and bioactivity against plant pathogenic fungi of these isolates was examined. A myxobacterial isolate KR025 showed good antifungal activities against Pyricularia oryzae, Cryphonectria parasitica, Colletotrichum lagenarium, and C. gloeosporioides but did not against Rhizoctonia solani, Fusarium oxysporum and Pythium ultimum. The bacterium was identified as Myxococcus fulvus based on morphological and physiological characteristics. Antifungal substances were extracted from culture broth and bacterial cell of Myxococcus fulvus KR025 by ethyl acetate. Antifungal substance of Myxothiazole (100 ${\mu}{\textrm}{m}$/ml) produced by Myxococcus fulvus KR 025 controlled 97.0% rice blast, tomato late blight, wheat leaf rust, and barley powdery mildew and showed 45.0 and 82.6% disease control of rice sheath blight and cucumber gray model, respectively.

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Laf Blight of Peony caused by Phytophthora cactorum (oral)

  • Kim, B.S.;Y.S. Lim;Kim, J.H.
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.127.3-128
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    • 2003
  • A leaf blight disease was found on peony plants growing in the first author's apartment garden in May, 2003. A species of Phytophthora was isolated from the lesions. The isolate readily produced sporangia and sex organs on V8 juice agar plates. Sporangia were papillate, ovoid to subspherical and caduceus with a pedicel. Sporangia were 33.6-38.4 ${\times}$ 33.6$\mu\textrm{m}$ with 1/b ratio approximately 1.14, papillae 4-5$\mu\textrm{m}$ high, pedicels also 4-5$\mu\textrm{m}$ long. Oogonia were spherical, 28.8$\mu\textrm{m}$ in diameter. Antheridia were globose, 14.4$\mu\textrm{m}$ in diameter and mating with oogonia paragynously. Mycelia grew best at 30$^{\circ}C$ and did not grow at 35$^{\circ}C$ or above, and at 5$^{\circ}C$. The morphological characteristics conformed to P. cactorum.

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