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Download Disease Cycle of Late Blight of Potato
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CROP: Potato Pathogen: Phytophthora infestans Distribution – Temperate and tropical climates worldwide Potato late blight is one of the most devastating plant diseases. The epidemics that destroyed potato crops in Europe in the 1840s led to mass starvation. For example, in the Great Irish Famine of 1845 black/brown lesions on leaves and stems that may be small at first and appear watersoaked or have chlorotic borders, but soon expand rapidly and become necrotic relative humidity is < 90%. Sporulation occur at 18-22°C Sporangia germinate directly via a germ tube at 21-26°C . Late Blight of Potato and Tomato In the absence of the oospore stage, Phytophthora infestans survives between potato crops as mycelium in infected tubers If infected tubers are left behind at harvest, sporangia may be produced on the infected tubers or new sprouts in the following spring. Air currents carry sporangia to healthy potato foliage. In the presence of water and at cooler temperatures, sporangia germinate indirectly by the production of zoospores . At warmer temperatures, the sporangia germinate directly by the production of a germ tube. New sporangia are produced on sporangiophores which emerge from stomata and may be dispersed by wind or water. Sporangia may also come through the soil to infect tubers. If both mating types come into contact with each other, thick-walled oospores may be produced to persist in soil or plant tissues. Oospores usually germinate by producing a sporangium . use disease-free seed - use fungicidal sprays - Use appropriate cultural practices - That’s all Group Topic A Overview of Plant defense against pathogen B Plant disease management strategies in organic farming C Virus transmission by parasitic higher plant D Host resistance disease management strategies E Importance and modern trends in Plant Pathology F Changes in Plant behaviour because of virus attack G Chemical and mechanical incasion mechanism of pathogen H Important Fungal, Bacterial, Viral and nematode diseases of cereal crops I Ecosystem dynamics due to plant diseases J Mycoviruses K How pathogen recognition happens in plants: A molecular view
