• Title/Summary/Keyword: copper sprays

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Control Efficacy of Different Types of Chemicals with Different Spraying Schedules on Plum Bacterial Black Spot (약제별 및 살포시기별 자두 검은점무늬병 방제효과)

  • Ryu, Young Hyun;Lee, Joong Hwan;Kwon, Tae Young;Kim, Seung Han;Kim, Dong Geun
    • Research in Plant Disease
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    • v.18 no.4
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    • pp.349-353
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    • 2012
  • Xanthomonas arboricola pv. pruni causes black spot symptom on fruit of plum, resulting in yield loss by reduction of marketable fruit production. To develop an effective control program, some chemicals were sprayed in various scheme during dormant season and growing season after blooming period. Copper-based chemicals were sprayed during dormant season and antibiotic-based chemicals were sprayed during fruit growing season. Sprays of antibiotic-based chemicals in growing season was more effective than copper-based chemicals sprays in dormant season. Three applications of antibiotic-based chemicals in 10 days interval starting 10 days after full blooming controlled disease incidence as much as 93%, whereas applications of copper-based chemicals in dormant season controlled 26-42%. Antibiotic-based chemicals application starting 10 days after full blooming was more effective than starting 20 or 30 days after full blooming.

Study on Boiling Heat Transfer of FC-77 in Spray Cooling (FC-77의 분무냉각 비등열전달 특성에 관한 연구)

  • Kim, Yeung-Chan
    • Journal of ILASS-Korea
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    • v.12 no.4
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    • pp.179-184
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    • 2007
  • The boiling heat transfer was experimentally investigated for the FC-77 sprays impacting a square heated test surface in a downward direction. Full cone spray nozzles were employed for the spray cooling experiment, and experiments were made under the test conditions of $Q=3.32{\times}10^{-6}{\sim}2.30{\times}10^{-5}\;m^3/s$, ${\Delta}T_{sub}=20{\sim}70^{\circ}C$. Also, heat transfer measurements were made using the copper block of $10{\times}10\;mm^2$ test area heated by nine cartridge heater. From the experimental results, correlation between the Nusselt number and Reynolds number based on droplet-flow-rate was developed. The correlation shows good predictions with ${\pm}30%$ error for FC-77.

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Experimental Study on Boiling Heat Transfer of PF-5052 in Spray Cooling (PF-5052의 분무냉각 비등열전달에 관한 실험적 연구)

  • Kim, Yeung-Chan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.12
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    • pp.938-944
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    • 2008
  • The boiling heat transfer was experimentally investigated for the PF-5052 sprays impacting a square heated test surface in a downward direction. Full cone spray nozzles were employed for the spray cooling experiment, and experiments were made under the test conditions of Q=$3.32{\time}10^{-6}{\sim}\;12.98{\time}10^{-6}m^3/s$, ${\Delta}T_{sub}=5{\sim}25^{\circ}C$. Also, heat transfer measurements were made using the copper block of $10{\time}10mm^2$ test area heated by nine cartridge heater. From the experimental results, correlation between the Nusselt number and Reynolds number based on droplet-flow-rate was developed. The correlation shows good predictions with ${\pm}30$ % error for PF-5052.

Management of Citrus Canker in Argentina, a Success Story

  • Canteros, B.I.;Gochez, A.M.;Moschini, R.C.
    • The Plant Pathology Journal
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    • v.33 no.5
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    • pp.441-449
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    • 2017
  • Citrus canker is an important bacterial disease of citrus in several regions of the world. Strains of Xanthomonas citri type-A (Xc-A) group are the primary pathogen where citrus canker occurs. After Xc-A entered the Northeast of Argentina in 1974, the disease spread rapidly from 1977 to 1980 and then slowed down and remained moving at slow pace until 1990 when it became endemic. Citrus canker was detected in Northwest Argentina in 2002. This paper presents the main steps in the fight of the disease and the management strategies that have been used to control citrus canker at this time. We think the process might be usefull to other countries with the same situation. Results from more than 40 years of research in Northeast (NE) Argentina indicate that we are at the limit of favorable environment for the disease. The severity of citrus canker is greatly affected by the environment and El $Ni{\tilde{n}}o$ Southern Oscillation (ENSO) phenomenon which causes cyclic fluctuations on the disease intensity in the NE region. Weather-based logistic regression models adjusted to quantify disease levels in field conditions showed that the environmental effect was strongly modulated by the distance from a windbreak. Production of healthy fruits in citrus canker endemic areas is possible knowing the dynamics of the disease. A voluntary Integrated Plan to Reduce the Risk of Canker has been in place since 1994 and it allows growers to export unsymptomatic, uninfested fresh fruit to countries which are free of the disease and require healthy, pathogen free fruits. The experience from Argentina can be replicated in other countries after appropriate trials.