Cankers are localized dead areas in the bark of stems, branches or twigs of many types of trees and shrubs, and are usually caused by fungi. We observed severe canker symptoms in oak trees located in Gyeongnam province in 2011. A total 31 trees were discovered with cankers of varied size, with an average of 48.5 × 15.2 cm. Black, half-rounded globular mound shaped stromata were associated with ...

Previously we showed in laboratory studies that the fungivorus nematode, Aphelenchoides hylurgi, was attracted to and fed upon the chestnut blight fungus, Cryphonectria parasitica, from American chestnut bark cankers and was a carrier of biocontrol, white hypovirulent C. parasitica strains. In the present field study, we recovered Aphelenchoides spp. in almost all (97.0 %) of 133 blight canker ...

What is thousand cankers disease of walnut? Thousand caners disease (TCD) is a newly recognized disease (2008) of certain walnut species (Juglans) caused by a fungus (Geosmithia morbida) that is vectored by a bark beetle (Pityophthorus juglandis, the “walnut twig beetle”). Thousand cankers disease has produced widespread death of walnuts in many western states during the past decade. In recent ...

Thousand cankers disease (TCD) is a newly recognized disease of various species of walnut (Juglans). Black walnut (Juglans nigra) is particularly susceptible to TCD and during the past decade it has devastated plantings of black walnut in most western states. In July 2010 thousand cankers disease was found over an extensive area around Knoxville, Tennessee, the first finding of TCD within the n...

ABSTRACT Sustainable biological control of the chestnut blight fungus Crypho-nectria parasitica with hypovirulence depends on the production and dissemination of hypovirus-infected propagules of the pathogen. We investigated the ability of C. parasitica to sporulate and produce hypo-virus-infected spores on recently dead chestnut wood in coppice stands in southern Switzerland where hypovirulenc...

Leaf scorch, top dieback, and lethal bole cankers were found in two progeny tests of sycamore in Mississippi. Both tests indicated that southern seed sources are more disease resistant than northern seed sources and that some progenies within seed source have even greater resistance. Although eight organisms associated with one or more of the disease symptoms were identified, determination of t...

Dogwood canker is a serious production problem of unknown etiology. From May 1985 through April 1989, cankers from 290 flowering dogwood trees in 15 separate nurseries were sampled for nematodes. Seventy-three percent (213) of the cankers contained nematodes. Panagrolaimus rigidus (Schneider) Thorne (115/290) and Aphelenchoides spp. (91/290) were the most frequently collected taxa. Panagrolaimu...

Cryphonectria parasitica, introduced in the NE of Portugal since 1989, is now an important and widespread pathogen of chestnut (Castanea sativa Mill.) which causes losses in chestnut fruit production and led to decline and death of many chestnut trees. Hypovirulence, a virus mediated attenuation of fungal pathogenesis, has not been frequent until now in Portugal but recently some cases of heali...

Chestnut blight, Cryphonectria parasitica (Murrill) Barr, was reported in Portugal 1989. The disease rapidly spread within the chestnut region of Trás-os-Montes (the Northeast Portugal). Eradication and mechanical/burning exclusion failed to control natural hypovirulence is still absent or very low incidence. introduction human-assisted therapeutic therefore required disease. We presente here e...

B and Phomopsis/Diaporthe (P/D) spp. are fungal pathogens known to cause cankers on a variety of woody hosts such as avocado, grapevine, almond, citrus, cherry, plum, mango, and coast live oak. On avocado (Persea americana Mill.), the disease came to be known as Dothiorella canker because the pathogen most often isolated at the time was known as Dothiorella gregaria (2). However, new research h...