Category: Pathogen Profile

Symptoms of Bacterial spot on a bell pepper fruit.

Pathogen Profile: Xanthomonas euvesicatoria

Xanthomonas euvesicatoria What is Xanthomonas euvesicatoria? Xanthomonas euvesicatoria is a bacterium that causes bacterial spot disease in plants of tomatoes and peppers [1,2]. It is aerobic and has a long tail (flagellum), allowing it to move in water. Please refer to Figure 1 where the flagellum can be seen on the bottom right side of […]
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tomato bacteria Pseudomonas syringae

Pathogen Profile: Pseudomonas syringae

Pseudomonas syringae What is Pseudomonas syringae? The bacteria Pseudomonas syringae is a common plant pathogen mostly found in stems and leaves [1]. It infects a wide range of plants—including fruit trees, greenhouse vegetables, ornamentals, and field crops. Annually, the bacteria cause billions of dollars of damage worldwide from lost fruits, damaged trees, unmarketable ornamentals, and […]
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rhizoctonia tomato stem

Pathogen Profile: Rhizoctonia solani

Rhizoctonia solani What is Rhizoctonia solani? The fungus Rhizoctonia solani is a soilborne pathogen that spreads in wet and warm conditions. It infects many economically vital plants—including greenhouse vegetables, ornamentals, and field crops [1, 2]. Crops affected by this pathogen include peppers, lettuce, potatoes, tomatoes, rice, soybeans, wheat, lilies and turf grass. In fact, it […]
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Impatiens Necrotic Spot Virus lettuce

Pathogen Profile: Impatiens Necrotic Spot Virus

Impatiens Necrotic Spot Virus An emerging threat to greenhouse vegetables Impatiens necrotic spot virus first emerged in floriculture and nursery crops [1] and is now affecting and causing considerable losses to these greenhouse-grown vegetable crops such as cucumber, tomato, pepper, and lettuce [2]. An economic analysis done on two lettuce growers in the Salinas Valley […]
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ralstonia bacterial wilt tomato potato

Pathogen Profile: Ralstonia solanacearum

Written by: Becky Anderson Published by: David Santos Ralstonia solanacearum What is Ralstonia solanacearum? The bacterial pathogen Ralstonia solanacearum is a Gram-negative, soil-borne bacterial pathogen that causes bacterial wilt and brown rot in potatoes. This bacterium belongs to a complex of four groups called phylotypes. These groups are known as the R. solanacearum species complex (RSSC). Each […]
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fusarium in banana root

Pathogen Profile: Fusarium oxysporum

Written by: Becky Anderson Published by: David Santos What is Fusarium oxysporum? Fusarium oxysporum is a fungus which can cause root rot, crown rot and, most commonly, wilting in a wide variety of crops such as basil, lettuce, cannabis and tomatoes (Figure 1). Wilting caused by F. oxysporum is known as Fusarium wilt and is a common […]
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Figure 3. Powdery mildew on watermelon leaves, caused by Sphaerotheca fuliginea, Erysiphe cichoracearum. 

Pathogen Profile: Podosphaera xanthii

Written by: Becky Anderson Published by: David Santos What is Podosphaera xanthii? Podosphaera xanthii is a pathogenic fungus which causes “powdery mildew” on plants, especially cucurbits [1]. The naming of this fungus is not standardized, and you may also know it as Podosphaera fusca, Sphaerotheca fuliginea or Sphaerotheca fusca [1]. In addition to P. xanthii, powdery mildew […]
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lettuce soft rot

Pathogen Profile: Pectobacterium carotovorum 

Written by: Becky Anderson Published by: David Santos What is Pectobacterium carotovorum? Pectobacterium carotovorum is one pathogen, of many, that causes soft rot in plants. It is a Gram-negative, rod-shaped, facultative anaerobe [1], (Figure 1). This bacteria is part of the order Enterobacterales [2] which includes other well-known bacteria such as Escherichia coli, Klebsiella pneumoniae and Salmonella, to […]
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alfalfa hairy root Rhizobium

Pathogen Profile: Agrobacterium rhizogenes

Written by: Becky Anderson Published by: David Santos What is Agrobacterium rhizogenes? Agrobacterium rhizogenes, also currently known as Rhizobium rhizogenes (1), is a Gram-negative, rod shaped, pathogenic bacteria (2) (Figure 1). A. rhizogenes lives in the rhizosphere, which is where the name derived (rhiza a root and gennao to make or to produce; hence, rhizogenes or root-producing).  […]
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tomatoes infected tobrfv

Pathogen Profile: Tomato Brown Rugose Fruit Virus

What is ToBRFV? Tomato brown rugose fruit virus, commonly known as ToBRFV, is a virus belonging to the genus Tobamovirus. This virus has been around since 2014, when it was first discovered in Israel [1]. Although it is too early to estimate global crop production damage, data gathered from Florida, USA showed an estimated 30% – […]
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