Nectria Research Articles

Increase Of Death Malady And Energy Situation Of Trees Of Choosy Aspect During A Frequently Contribute Fagus Beam-Point Stance

We tend to compare the results of observations of bark death malady and defoliation of Fagus absorptive organs administrated in 1998 and 2002. A frequently managed, 53-year previous Fagus beam -point interchange Central European country was chosen as Associate in Nursing object of our analysis. it had been found that death malady had Associate in Nursing increasing trend. The degree of death malady indicated on trees of choosy aspect that area unit the most focus of interest of silvicultural managers was not up to the degree of death malady on the opposite trees within the same stance layer (trees of undiscriminating quality). The defoliation of absorptive organs wasn't influenced by Associate in Nursing increasing trend of death malady increase . it had been confirmed that the strategy of crown thinnings realized with the aim to support the trees of choosy quality, combined with healthful choice, was affordable conjointly in Fagus beam -point stances suffering from gangrene. throughout the analysis amount within the studied stance we tend to detected four tracheomycotic fungi of Nectria (Fr.) Fr. genus and 2 species of imperfect fungi of the genus Cylindrocarpon Wollenw. and fungus Nees.

FIRST REPORT OF NECTRIA HAEMATOCOCCA ASSOCIATED WITH DIEBACK OF OLIVE TREES IN TUNISIA

During a routine survey for olive diseases conducted in autumn 2013 in southern Tunisia (Bir Ali region), wilting and chlorosis of the leaves accompanied by brown-to-black discoloration of the wood in cross-sectioned twigs were observed on 3- to 10-year-old olive trees. On potato dextrose agar (PDA), a fungus was isolated from symptomatic twigs and branches with an initially white mycelium that over time became light gray-brown. This fungus was identified as Nectria sp. based on morphological characteristics and analysis of the ITS gene region (White et al., 1990). A BLAST search of GenBank database revealed 99% homology of the amplified product with a reference sequence of Nectria haematococca (strain HLJ_14, accession No. JN088237.1). Pathogenicity tests were conducted on 10 two-year old olive trees of cv. Chemlali, by placing a mycelial plug in a shallow wound on the stem of each plant. Control plants were inoculated with sterile PDA plugs. Two months post inoculation, symptoms appeared, with stems showing brown discolorations and necrotic lesions. Controls remained healthy. N. haematococca was recovered from necrotic lesions, thus fulfilling Koch's postulates. N. haematococca was held responsible for root rot of olive trees in Argentina (Barreto et al., 2003). To our knowledge this is the first report of N. haematococca as a causal agent of dieback of olive trees in Tunisia.

<i>Neonectria fuckeliana</i> infection of <i>Pinus radiata</i> nursery stock

Nectria flute canker is a disease of Pinus radiata stems caused by Neonectria fuckeliana The fungus is not known in the North Island leading to concern that it may be transported north via asymptomatically colonised nursery stock Wounded P radiata seedlings and cuttings were exposed to natural inoculum from an adjacent infected forest and half were artificially inoculated No disease symptoms were recorded throughout the trial Neonectria fuckeliana was reisolated from 24 and 7 of inoculated seedlings and cuttings respectively 3 months after inoculation and at 12 months from 35 of the remaining inoculated seedlings only Neonectria fuckeliana was not isolated from uninoculated seedlings or cuttings exposed to natural inoculum These results indicate that nursery plants have little capability of retaining N fuckeliana within the tissue even when directly inoculated Nursery stock is therefore unlikely to be a pathway for transport of the fungus

Summer pruning of apple: impacts on disease management

Pruning, including summer pruning, of apples can have a positive impact on disease management in two basic ways: through removal of dead tissue and inoculum, and through alteration of the canopy microclimate. Summer pruning can also increase diseases if it is done when disease risk is high. However summer pruning is used almost exclusively as a horticultural tool to improve fruit quantity and quality. As orchard planting and training systems have moved from semi-dwarf trees to high-density, fully-dwarf trees, very few summer pruning studies have looked at impacts related to disease, yet summer pruning in high-density systems may have important disease management effects. Growers should avoid summer pruning practices which will increase disease risks, and use those that offer both horticultural and disease management benefits. More research in this area is needed, as cultural components of apple disease management will become increasingly important in sustainable production systems. This review looks at important apple diseases, including apple scab, fire blight, sooty blotch and flyspeck, black rot, white rot, Nectria canker and powdery mildew, and uses dormant pruning studies plus knowledge of the epidemiology of the diseases to suggest ways that summer pruning would be expected to impact disease management.

Reappearance of Nectria polyporina

Reappearance of Nectria polyporina

A Revision of the Fungi Formerly Classified as Nectria Subgenus Hyphonectria

A Revision of the Fungi Formerly Classified as Nectria Subgenus Hyphonectria

A Revision of the Fungi Formerly Classified as Nectria subgenus Hyphonectria

A Revision of the Fungi Formerly Classified as Nectria subgenus Hyphonectria

Taxonomy and Morphology of Hypocrea Citrina

A new variety of Hypocrea citrina is described. It and H. citrina var. citrina have asci and perithecia of the Nectria developmental type, but in addition produce short basal paraphyses early in ce...

Heliscus submersus sp.nov., an aquatic hyphomycete from Jamaica

Heliscus submerstis sp.nov. is described from submerged decaying leaves and petioles. Its behaviour in culture is compared with that of Nectria lugdunensis .

Cytoplasmic Variation in Nectria stenospora

DURING an investigation of the suitability of Nectria stenospora Berk, and Br. for the study of fungal variation, a case of cytoplasmic variation occurred which, at first appearance, closely simulated a gene-controlled effect.