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Erysiphe graminis f.sp. tritici is a plant pathogen that causes a fungal infection known as powdery mildew. It is most common in grains, and it can be identified by the characteristic white spots on leaves and stems that appear to be made of powder. Powdery mildew is one of the most widespread and easily recognizable plant diseases.
Red ring rot is common in North America. The pathogen Porodaedalea pini is widely spread in the temperate zone in the Northern Hemisphere. [4] It infects a wide range of coniferous trees, including jack pine, lodgepole pine, Sitka and white spruce, Douglas-fir, balsam and true fir, western hemlock, and tamarack.
Plant pathology or phytopathology is the scientific study of plant diseases caused by pathogens (infectious organisms) and environmental conditions (physiological factors). [1]
Plant diseases are diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). [1] Organisms that cause infectious disease include fungi , oomycetes , bacteria , viruses , viroids , virus -like organisms, phytoplasmas , protozoa , nematodes and parasitic plants . [ 2 ]
Since most plant pathogens are Gram-negative detection of Gram-positive bacterium, using methods such as the KOH test, is a beginners diagnostic tool used to identify this bacterium. [12] Bacteria may be detected beneath the seedcoat by means of a combined cultural and slide agglutination test. Bean seed from countries where the disease is ...
Relative to a susceptible plant, disease resistance is the reduction of pathogen growth on or in the plant (and hence a reduction of disease), while the term disease tolerance describes plants that exhibit little disease damage despite substantial pathogen levels.
It is a destructive disease of fruits, vegetables, and ornamentals found worldwide, and affects genera from nearly all the plant families. The bacteria mainly attack the fleshy storage organs of their hosts ( tubers , corms , bulbs , and rhizomes ), but they also affect succulent buds, stems, and petiole tissues.
The disease starts out as yellowing and drooping on one side of the plant. Leaf wilting, plant stunting, browning of the vascular system, leaf death and lack of fruit production also occur. [8] F. oxysporum f. sp. melonis attacks muskmelon and cantaloupe. It causes damping-off in seedlings and causes chlorosis, stunting and wilting in old plants.