ARMILLARIA MELLEA

The Armillaria mellea fungus is the cause of a disease in the sensitive plants that causes the rot of the radicular system, which kills to the plant by starvation, since it prevents him to absorb the water and the nutrients of the ground.  The aerial parts of the affected plant are free of the fungus.  This has allowed to take me cuttings of the same ones and to reproduce them through grafts or of the taken root one with hormones, to the first symptoms of affectation, before their definitive death. 

 

The Armillaria mellea is one of the greater phyto-sanitary problems of the Garden.  Every year is the cause of the death of a dozen of trees and shrubs, that die thundered against after the springlike budding-flowering.  In the middle of Autumn the mushrooms leave the Armillaria next to the base of the trunk of the affected trees.  Frequently, once taken tree, they continue leaving mushrooms during years in the pieces roots that have been in the ground.  The fungus transmits itself by the spores that emit the mushrooms.  If a spore falls in a wound of the crust of sensitive tree, germinates and begins to invade it with the filaments of his micelium, that are eating the cambium that is the most nutritious and tender part of tree, forming a target-grayish filament maze under the crust.  Affected tree begins to languish but it follows alive, until in the Spring, with the resumption of the circulation of the sap, the fungus also it is reactivated and it ended up killing tree of sudden form, when not being able this one to feed the new buds and flowers.

 

 

With the death of tree the Armillaria does not die but that continues growing under the ground extending its filaments by the finest roots and, when it contacts with the root of another sensitive plant, also invades it, extending by the subsoil as an oil spot, going of tree in tree.  This way it is killing all the plants that find in their way, respecting solely the resistant plants or the moderately resistant ones, that are the able ones to synthesize vegetal antibodies against the fungus, so that, although they are invaded by this one, the antibodies more or less quickly destroy the fungus and stops their invasion.  It is possible to destroy the fungus when the affected plant is only beginning its invasion starting of root.  Later all the parts of the plant must be burned in the same hole, coverall the base with the main roots.  In the case of a greater invasion little it is possible to be done, since the fungus is in the subsoil and you do not go away.  The only way to end him is to seed a resistant tree entanglement, that prevents their expansion.

 

In this photo of the base of the trunk of an Elder, Sambucus nigra, is directly appraised white micelium of the Armillaria melles that has caused the rot of the system to radicular and the emission by roots of the subcortical cambium that go towards the ground, as strategy to survive the attack of the fungus.  The Elder was practically dead with the dry leaves, but, after weeks, it directly sprouted again thanks to the emission by roots of the trunk.

 

In the following list I have put the plants whose sensitivity or resistance to the Armillaria I have verified by my same one.  The plants with intermediate resistance were attacked by the Armillaria and survived.

SENSIBILITY

INTERMEDIATE RESISTANCE

RESISTANCE

Acacia dealbata

Cryptomeria japonica

Acrocarpus fraxinifolius

Acacia longifolia

Eryobotria japonica

Anagyris foetida

Acacia trineura

Ficus carica

Buxus balearica

Actinidia chinensis

Persea gratissima

Buxus sempervirens

Adansonia digitata

Pyrus communis

Casimiroa edulis

Agave attenuata

Sechium edule

Ceratonia siliqua

Alnus incana

Sambucus nigra

Citrus aurantium

Annona cherimolia

Trachycarpus fortunei

Cydonia oblonga

Carica papaya

 

Cyphomandra betacea

Citrus paradisi

 

Fraxinus excelsior

Cedrus deodara

 

Juniperus chinensis

Cupressus arizonica

 

Juniperus virginiana

Erythrina caffra

 

Livistona chinensis

Eucalyptus gunnii

 

Lucuma mammosa

Feijoa sellowiana

 

Myrtus communis

Harpephyllum caffrum

 

Pinus pinea

Juniperus phoenicea

 

Pinus halepensis

Kigelia africana

 

Pistacia lentiscus

Lavandula stoechas

 

Psidium friedrichsthalianum

Leucaena glauca

 

Psidium guajava

Litchi sinensis

 

Prunus cerasus

Malus pumilla

 

Quercus ilex

Mangifera indica

 

Robinia pseudoacacia casque rouge

Morus alba

 

Tilia cordata

Opuntia robusta

 

 

Passiflora alata

 

 

Passiflora edulis var. edulis

 

 

Passiflora mollissima

 

 

Pistacia vera

 

 

Prunus amigdalus

 

 

Prunus armeniaca

 

 

Prunus avium

 

 

Prunus cerasifera

 

 

Prunus persica

 

 

Psidium littorale longipes

 

 

Quercus coccifera

 

 

Rosa ssp.

 

 

Sequoia sempervirens

 

 

Tamarix gallica

 

 

Thuia orientalis

 

 

Vitex agnus-castus

 

 

Vitis vinifera

 

 

 

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