Information AboutPlant Disease |
| CATEGORIES ABOUT PHYTOPATHOLOGY | |
| phytopathology | |
| plant pathogens and diseases | |
| agronomyphytopathology | |
| plant pathogens and diseases | |
| agronomy | |
| branches of botany | |
| botany | |
| pathology | |
| SHOPPER'S DELIGHT | |
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Common plant pathogens (in rough order of importance) include species from these groups: : Fungi - the most common pathogens (root rot fungi, molds, rusts, and mildews). : Water Molds (Oomycetes) - such as ''Phytophthora infestans'' ( Potato Blight ). : Bacteria - Prokaryotic organisms which include as many as 18 genera. : Virus es - more than 700 are plant pathogens, comprised of only Protein and DNA . : Roundworm s (Nematoda) - both as pathogens and Vectors , the only animals normally regarded as plant pathogens. : Viroid s - small, single-stranded RNA pathogens causing a dozen plus diseases. :Parasitic Angiosperms - plants that parasitize other plants, Mistletoe and witchweed are common examples. : Slime Mold s (Myxomycetes) - usually not actual pathogens but may be aesthetically unpleasant. : Phytomyxea - true pathogens represented by the genera ''Polymyxa'' and ''Plasmodiophora'' FUNGAL PLANT PATHOGENS The majority of plant pathogens are fungal, with Ascomycetes the leading group. Fungal plant pathogens can be described as polycyclic if the disease is capable of making spores and reinfecting plants during a growing season, or monocyclic if it has to wait until a new season. Fungal pathogens are also defined by the types of Spore s they create and the methods by which they enter the plant tissue. Once the pathogen enters the plant tissue it either creates a Haustorium and grows inside the living tissue ( Biotroph ) or kills the surrounding cells and lives off the dead tissue ( Necrotroph ). Indications of pathogen presence are divided into signs and symptoms. Sign s are observational evidence of the pathogen (such as visible Sporulation ). Symptom s are secondary evidence that a pathogen is present (such as Wilt ing of the leaves). Significant abiotic disorders can be caused by: :''Natural'' :: Drought :: Frost damage, and breakage by Snow and Hail :: Flood ing and poor drainage :: Nutrient deficiency :: Salt deposition and other soluble mineral excesses (e.g. Gypsum ) :: Wind (windburn, and breakage by Hurricane s and Tornado s) :: Lightning and Wildfire (also often man-made) :''Man-made'' (arguably not abiotic, but usually regarded as such) :: Soil compaction :: Pollution of air and/or soil :: Salt from winter road salt application :: Herbicide over-application ::Poor education and training of people working with plants (e.g. lawnmower damage to trees) :: Vandalism SEE ALSO EXTERNAL LINK
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