11 torthaí
A new Phytophthora pathogen of trees and shrubs, previously informally designated Phytophthora taxon C, is formally named here as P. kernoviae. P. kernoviae was discovered in late 2003 during surveys of woodlands in Cornwall, south-west England, for the presence of another invasive pathogen, P.
European beech (Fagus sylvatica) is an important forest tree species common in northern and central Europe. In Italy, this species is typical in mountain areas over 1,000 m above sea level. In the last decade, decline and death was reported on European beech caused by several Phytophthora species
Phytophthora cactorum, P. citricola I, and P. plurivora cause bleeding cankers on mature European beech (Fagus sylvatica) trees in the northeastern United States. Inoculation experiments were conducted to compare the aggressiveness of the three Phytophthora spp. on stems, leaf disks, and roots of
During 2005 and 2006, eight declining, mature Fagus sylvatica trees with severe crown dieback were encountered at two stands near Ljubljana and Kamnik in central Slovenia. Bleeding cankers were seen mostly in the lower parts of the stem. Fresh cankers showed orange brown necroses of the inner bark
Phytophthora citricola and P. cactorum cause bleeding cankers that lead to the death of mature European beech (Fagus sylvatica) in the northeastern United States. The effects of two fungicides and a plant growth regulator on in vitro pathogen characteristics and on canker expansion were
During the last decade, typical symptoms of Phytophthora diseases were observed in beech stands of several European countries. The main symptoms were the presence of bleeding cankers on the stem, a low crown density as well as the yellowing of foliage and the small size of leaves. Several species of
Phytophthora ramorum causes bleeding cankers of trunks of trees native to the west coast of the United States (i.e., Quercus kelloggii, Q. parvula var. shrevei, and Lithocarpus densiflorus). In the United Kingdom so far, bleeding cankers caused by inner bark infections have been found on Aesculus
The analysis of stable isotope composition (delta13C, delta15N, delta18O) of phloem-transported organic matter is a useful tool for assessing short-term carbon and water balance of trees. A major constraint of the general application of this method to trees at natural field sites is that the
In autumn 2001, bleeding cankers were observed on the basal portion of the trunk of a declining tree in a forest stand of European beech (Fagus sylvatica L.) in Latium (central Italy). A Phytophthora sp. was isolated consistently from infected trunk bark using whole apples as bait. Isolations were
During 2006 and 2007, declining mature beech trees (Fagus sylvatica) were recorded in two stands in the Natural Park of Monti Cimini in central Italy. Symptoms included crown thinning and the presence of bleeding lesions on the main roots and lower stem. Incidence of decline was approximately 5%.
A homothallic, papillate Phytophthora species causing foliar and fruit blight of noni (Morinda citrifolia var. citrifolia) in Hawaii was identified. The asexual phase of this species is characterized by the production of umbellate sporangiophores and papillate sporangia that are ellipsoid and