Spatial dispersal of Nectria ditissima canker of beech in an international provenance trial

Abstract

Beech canker caused by Nectria ditissima was abundant in many plots of a large beech provenance trial in Germany. In 149 plots a total of 9015 plants were assessed. No difference in susceptibility of individual provenances was established. However, significant spatial correlation was found between canker incidence in the plantation and the distance to neighbouring diseased shelterwood. The latter evidently served as a source of inoculum. Predominant juveniles tended to be more infected presumably by being more exposed to the inoculum. Trees planted up to 20 m from diseased shelterwood were most significantly infected, up to 48% per plot. In order to ascertain the role of wind for dispersing inoculum, distance zones were combined with locally predominant wind directions. The resulting wind dispersal zones served better for modelling disease dispersal than the distance zones.

Radial-growth and wood anatomical changes inAbies albainfected byMelampsorella caryophyllacearum: a dendroecological assessment of fungal damage

“…Similar observations have been made on Pseudotsuga menziesii and on Tsuga mertensiana affected by the root rot pathogen Phellinus weirii [18]. It seems that taller trees are more readily exposed to fungal propagules, a finding that is consistent with the distribution of Nectria ditissima cankers on beech trunks [21]. Swellings in the lower stem may have been initiated quite early, and swellings in upper parts must have developed later, when the trees had reached the respective height.…”

“…Mean diameters (± SD) of disks of the felled trees were significantly (P ≤ 0.05) higher at the swelling level (31.9 ± 1.6 cm), Brooms on trunk -9.0 (7-11) 15.8 (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) Brooms on branches --12.5 (10)(11)(12)(13)(14)(15)(16) than at 60 cm above and below the swelling level (23.5 ± 1.7 and 25.2 ± 2.9 cm, respectively). Only the oldest tree showed rot xylem, with percentages of transversal rot area at the swelling level, 60 cm above, and 60 cm below of 37, 22, and 18%, respectively.…”

Antifungal effect of bark extracts from some European tree species

“…Nectria ditissima infection seems to occur via leaf scars, small wounds caused by feeding insects and late frost injuries (Metzler et al 2002) on deciduous trees. The related N. fuckeliana is a weak wood pathogen on conifers, as well as a common wound inhabiting species, causing necrotic bark canker (Langrell 2005).…”

Cut-off shoots method for estimation of partial resistance in apple cultivars to fruit tree canker caused byNeonectria ditissima

“…This pathogen can infect apple by either conidia or ascospores during all growth stages and attack trunks, branches, shoots and fruit. The main avenue for infection is leaf scars, but damage occurs also in pruning wounds, cracks and frost injuries (Metzler et al 2002;Plante et al 2002;Mccracken et al 2003;Xu & Robinson 2010).…”