• Title/Summary/Keyword: nonchemical control

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Effects of Ionizing Radiation on Postharvest Fungal Pathogens

  • Jeong, Rae-Dong;Shin, Eun-Jung;Chu, Eun-Hee;Park, Hae-Jun
    • The Plant Pathology Journal
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    • v.31 no.2
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    • pp.176-180
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    • 2015
  • Postharvest diseases cause losses in a wide variety of crops around the world. Irradiation, a useful nonchemical approach, has been used as an alternative treatment for fungicide to control plant fungal pathogens. For a preliminary study, ionizing radiations (gamma, X-ray, or e-beam irradiation) were evaluated for their antifungal activity against Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer through mycelial growth, spore germination, and morphological analysis under various conditions. Different fungi exhibited different radiosensitivity. The inhibition of fungal growth showed in a dose-dependent manner. Three fungal pathogens have greater sensitivity to the e-beam treatment compared to gamma or X-ray irradiations. The inactivation of individual fungal-viability to different irradiations can be considered between 3-4 kGy for B. cinerea and 1-2 kGy for P. expansum and R. stolonifer based on the radiosensitive and radio-resistant species, respectively. These preliminary data will provide critical information to control postharvest diseases through radiation.

Comparative study of two collagen membranes for guided tissue regeneration therapy in periodontal intrabony defects: a randomized clinical trial

  • Chung, Young-Mi;Lee, Jue-Yeon;Jeong, Seong-Nyum
    • Journal of Periodontal and Implant Science
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    • v.44 no.4
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    • pp.194-200
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    • 2014
  • Purpose: The purpose of this study was to assess and compare the clinical and radiographic outcomes of guided tissue regeneration therapy for human periodontal intrabony defects using two different collagen membranes: a porous nonchemical cross-linking collagen membrane (NC) and a bilayer collagen membrane (BC). Methods: Thirty subjects were randomly assigned and divided into the following 3 groups: a test group (NC+BM), in which a NC was used with xenograft bone mineral (BM), a positive control group (BC+BM), in which a BC was used with xenograft BM, and a negative control group (BM), in which only xenograft BM was used. The following clinical measurements were taken at baseline and 3 months after surgery: plaque index, gingival index, probing pocket depth, gingival recession, and clinical attachment level. Radiographic analysis was performed at baseline, 1 week and 3 months after surgery. Results: Membrane exposure was not observed in any cases. Significant probing depth reduction, attachment-level gain and bone fill were observed for both test and control groups compared to baseline at 3 months after surgery (P<0.05). However, there were no statistically significant differences in clinical improvement and radiographic bone fill between treatment protocols (P>0.05). Conclusions: Within the limitations of this study, the results suggest that both NC and BC were comparable in terms of clinical and radiographic outcomes for the treatment of periodontal intrabony defects in human subjects.

Status and Perspective of Bioherbicde Development for Organic Weed Management (친환경 잡초방제를 위한 생물제초제의 상용화 현황)

  • Pyon, Jong Yeong;Lee, Jeung Joo;Park, Kee Woong
    • Weed & Turfgrass Science
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    • v.6 no.1
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    • pp.1-10
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    • 2017
  • Weed management under organic farming systems is very problematic since organic agriculture does not allow synthetic herbicides. Bioherbicide is needed to develop for weed management in organic agriculture systems. This review covers current status and perspectives of bioherbicide development for effective nonchemical weed management in organic farming systems. Bioherbicides are products of natural origin derived from living organisms, and more specifically bacteria, fungus and plants including natural metabolites for weed control. Bioherbicides derived from microorganisms or natural molecules are currently available on the pesticide markets. Devine, Lockdown (Collego), BioMal, Camperico, Organo-Sol and Opportune were derived from bacteria, Woad Warrior, Smolder, Mygogen, Chontrol Paste, Starritor and Phoma derived from fungus, and Katoun (pelargonic acid) and Beloukha were derived from plants. Corn gluten meal products and plant essential oils products are also available for nonselective weed control in organic agriculture. Organic weed management methods may be more feasible in small scale farming and high-value crops, and bioherbicides may be applied with other weed control practices in organic farming systems.

Control Effect of a Stored Grain Insect Pest, Tribolium castaneum, by 'CATTS' Postharvest Treatment (CATTS를 이용한 저곡해충 거짓쌀도둑거저리(Tribolium castaneum)의 소독 효과)

  • Son, Ye-Rim;Kim, Yong;Kim, Yong-Gyun
    • Korean journal of applied entomology
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    • v.49 no.4
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    • pp.363-369
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    • 2010
  • A postharvest treatment called CATTS (controlled atmosphere and temperature treatment system) has been used as an alternative nonchemical measure for methyl bromide fumigant treatment. This study applied CATTS to control the red flour beetle, Tribolium castaneum, infesting stored grains. Adults of T. castaneum were susceptible to $46^{\circ}C$ heat treatment. The susceptibility was further enhanced by addition of CA conditions (15% $CO_2$ and 1% $O_2$). When CATTS ($46^{\circ}C$, 15% $CO_2$, $16^{\circ}C/h$ treating rate) was applied to different developmental stages of T. castaneum, it showed 100% control efficacy by 120 min exposure. There was a variation in CATTS susceptibility among developmental stages, in which late instar larvae were most tolerant. Heat shock proteins of T. castaneum appeared to be implicated in the tolerance of CATTS.

Effect of Aqueous Extracts of Rice Bran on Inhibition of Germination and Early Growth of Weeds (쌀겨 추출물에 의한 잡초 발아 및 초기생장 억제 효과)

  • Kuk, Yong-In;Shin, Ji-San;Kwon, Oh-Do;Guh, Ja-Ock
    • Korean Journal of Environmental Agriculture
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    • v.20 no.2
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    • pp.108-111
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    • 2001
  • This study examined effects of aqueous extracts of rice bran on the inhibition of germination and early growth of annual weeds, barnyardgrass and eclipta. Germination of barnyardgrass treated with 5%(w/v)-sterilized and nonsterilized extracts of rice bran were inhibited by 27% and 63% at 7 days after treatment(DAT), respectively, compared to control. However, plant height and fresh shoot weight of barnyardgrass treated with aqueous extract of rice bran was reduced significantly at higher than 1% for both sterilized and nonsterilized extracts. Plant height and fresh shoot weight of barnyardgrass treated with 5% extract of rice bran were inhibited by 66 to 68% and 75 to 78% at 7 DAT, irrespective of sterilization. The germination of eclipta treated with sterilized and nonsterilized extracts of rice bran were significantly inhibited at concentrations of more than 0.5% and completely at 4% and 5%. Plant height and fresh shoot weight of eclipta affected by the rice bran extracts showed trends similar to the germination rate. The sterilization of rice bran extract resulted in higher inhibition of germination and early growth of eclipta. Rice bran extract was more inhibitory to the germination and growth of eclipta than barnyardgrass. These results suggest that aqueous extracts of rice bran may have inhibitory potential to germination and early growth of weeds.

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Sound Stress Alters Physiological Processes in Digestion and Immunity and Enhances Insecticide Susceptibility of Spodoptera exigua (스트레스 음파에 따른 파밤나방(Spodoptera exigua ) 소화 및 면역 생리작용 저하와 살충제 감수성 제고 효과)

  • Park, Jung-A;Seok, Jung-Kyun;Prasad, Surakasi Venkara;Kim, Yong-Gun
    • Korean journal of applied entomology
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    • v.50 no.1
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    • pp.39-46
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    • 2011
  • This study analyzed effects of different sound treatments in frequencies and intensities on digestion and immune physiological processes of the beet armyworm, Spodoptera exigua larvae. Without effect on egg hatch, sound treatments with 100-5,000 Hz at 95 dB suppressed feeding behavior and inhibited a digestive enzyme activity. In addition, two dimensional electrophoresis of midgut luminal proteins indicated a marked difference of the sound-treated larvae. In response to 5,000 Hz at 95 dB, larvae showed a significant decrease in hemocyte nodule formation against fungal challenge along with significant suppression in phospholipase $A_2$ activity in hemocyte and plasma. With increase of sound frequencies, the treated larvae showed an enhanced susceptibility to insecticides. Such sound frequency effect was significantly modulated with different sound intensities. These results suggest that sound treatment may give adverse stress to physiological processes of S. exigua larvae and may be applied to a nonchemical insect pest control.