Butt Rot Research Articles

Armillariella mellea . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Armillariella mellea [Armillaria mellea] . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: The fungus has been recorded as a pathogen on an extremely wide range of dicotyledonous and coniferous trees and shrubs (Raabe, 1962; Browne, 1968). It has also been found on potato (1: 357), narcissus (11: 376), strawberry (8: 727), bamboo (40: 436), geranium (12: 5227), sugarcane and banana (25: 355), but attack of monocotyledons and herbaceous plants is rare. DISEASE: Armillaria root rot. Armillaria root disease. Honey fungus. Armillariella mellea has two roles as a plant pathogen. It may act as a lethal pathogen by invading and destroying the cambium of the root and lower stem, following which it may colonize and rot the woody tissues of the host after its death, or it may cause a butt rot without attacking the living tissues of the host. Both types of disease have a patchy distribution in the field, characteristically spreading from inoculum centres in the soil, so that the hosts which have been most recently attacked are found at the edge of the patch. Where lethal attack occurs the host dies rapidly and (in the case of conifers and certain dicotyledonous trees) the bark of the roots and stem base is cracked and covered with gum or resin exudate. Thick, creamy-white, fan-like sheets of mycelium are found under the bark and these are frequently accompanied by flattened, dark brown rhizomorphs ( forma subcorticalis ). These rhizomorphs may also be epiphytic on roots and grow out into the soil, where their form is more cylindrical ( forma subterranea ). Sporophores may be formed on the host in advanced stages of the disease. The butt rot is a typical soft white rot with pronounced black zone lines. It seldom advances more than 1-2 m up the stem. The rotten wood is often luminous. Armillariella mellea also forms balanced mycorrhizal associations with the orchids Galeola septentrionalis and Gastrodia elata . GEOGRAPHICAL DISTRIBUTION: World wide, throughout forests of the temperate and tropic regions (CMI Map 143, ed. 3, 1969). TRANSMISSION: By infection of woody debris and stumps by air-borne basidiospores, by the growth of rhizomorphs through the soil, by root contact with infected soil debris and transport of infected plant material.

Inonotus weirii . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Inonotus weirii . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Abies amabilis, A. grandis, A. lasiocarpa, Chamaecyparis spp., Larix occidentalis, Picea engelmannii, P . sitchensis, Pinus contorta, P. monticola, P. ponderosa, Pseudotsuga menziesii, Thuja plicata, Tsuga heterophylla . DISEASE: Laminated butt rot and yellow ring rot of conifers. GEOGRAPHICAL DISTRIBUTION: North America (Western Canada, Oregon, Washington); Japan. TRANSMISSION: The disease is spread by root contact with infected material in the soil; there appears to be little spread of the fungus by growth through the soil. It is likely that infection of freshly exposed wounds takes place through airborne basidiospores.

Fomes annosus Root and Butt Rot: A Threat in Managed Stands in Coastal British Columbia

In coastal British Columbia stands, airborne spores of Fomes annosus are present throughout most of the year and are particularly numerous during October-November and February-March. Stumps of most commercial conifer species are susceptible to spore infection and the fungus can grow from diseased into healthy roots when in contact. Infection centers in immature stands have originated from mycelium present in stumps of the previous stands. Indications are that Fomes annosus root rot will be a significant problem should thinning become a common forest management practice if steps are not taken to control stump infection. Application of borax is recommended to reduce spore infection of stumps.

Modes of Infection and Spread of Fomes Annosus

The root and butt rot caused by Fomes annosus is one of the most eco­ nomically important diseases of conifers in the north temperate zone of the world. Sinclair (112) lists almost 150 species of trees, including some an­ giosperms, on which F. annosus has been reported. Species of Abies, Juni­ perus, Larix, Picea, Pinus, Pseudotsuga, and Tsuga are the major hosts. On most species of Pinus and Juniperus, F. annosus causes primarily a root rot and kills trees within several months to years after infection. The major exception is Pinus strobus, which is subject to typical butt rot as well as root rot, and trees usually remain alive for several years after infection un­ less windthrown. Spruces, true firs, larches, hemlocks, and Douglas fir may be killed by F. annosus when young, but later are primarily damaged by butt rot which may extend for several meters up the stem. Koenigs' (59) bibliography lists 438 references on F. annosus. Since then, more than 300 additional papers have been published. This review will not attempt to evaluate all aspects of the F. annosus problem. Instead, at­ tention will be focused only on the aspects of spread and infection which are important in devising controls for this disease. Regardless of host and type of disease produced, spread of F. a nnosus is accomplished in two major ways: (a) by spores, and (b) by growth of my­ celium across contacts between healthy and infected roots. Spores are re­ sponsible for initiation of new infection centers in previously uninfected stands whereas growth of mycelium at points of root contacts or grafts re­ sults in the enlargement of established infection centers. Factors relating to these two types of spread will be discussed separately.

Rigidoporus ulmarius . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Rigidoporus ulmarius . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Ulmus . Also reported on Acer, Aesculus, Populus, Robinia and Tilia . DISEASE: Elm butt rot. Forming a conical column of decayed wood in the lower part of the host stem, which becomes dark brown and friable, splitting into brick-shaped fragments with no mycelial sheets within the cracks. GEOGRAPHICAL DISTRIBUTION: Asia (India, Japan, U.S.S.R.); Europe (Cyprus, France, Germany, Great Britain, Italy, Portugal); North America (Mexico); Central America (British Honduras). TRANSMISSION: By air-borne spores.

Stem and Butt Rot Diseases of Forest Trees

Stem and Butt Rot Diseases of Forest Trees

DECAY OF LODGEPOLE PINE IN TWO FOOTHILLS SECTIONS OF THE BOREAL FOREST IN ALBERTA

Cull in lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) is highly variable in the B19a and B19c Sections of the Boreal Forest in Alberta, depending upon whether the wood is used for pulp or sawed products. Sixty-nine per cent of 2,436 sample trees were suspected of containing volumes of red heartwood stain and advanced decay on the basis of the presence of external defects. Fifty-three per cent of the suspects were sound, 36 per cent had red heartwood stain and 11 per cent were partly or entirely decayed. Sixty per cent of the trees without external defects were sound, and 40 per cent had red heartwood stain. In cubic-foot measure decay was unimportant in stands less than 100 years old. In older stands a few infested trees accounted for most of the decay. In foot-board measure 62 of 2,746 sample trees were totally culled and 122 were partially culled. Considerable loss occured in 90-year old and older stands near Whitecourt and in 170-year old stands in the other sample areas. Fomes pini (Thore) Lloyd and Polyporus tomentosus Fr. were the principal fungi isolated from white pitted trunk rots. P. tomentosus and Flammula alnicola (Fr.) Kummer were isolated most frequently from white pitted root and butt rots, and Coniophora puteana (Schum. ex Fr.) Karst. from brown cubical root and butt rots. Peniophora pseudo-pini Weres. and Gibson was the most frequently isolated fungus but was always associated with red heartwood stain. Scars of all kinds were the most important points of entry for decay fungi.

Butt rot fungi and their habitant (2)

Butt rot fungi and their habitant (2)

Butt-Rot and Death of Conifers

Butt-Rot and Death of Conifers

PATHOLOGICAL CONDITION OF IMMATURE BALSAM FIR STANDS OF HYLOCOMIUM-OXALIS TYPE IN THE LAURENTIDE PARK, QUEBEC

The pathological condition of fully stocked immature balsam fir stands was investigated in the Hylocomium-Oxalis forest type in the Laurentide Park. Phacidium infestons Karst. was the only foliage disease associated with severe defoliation of trees of all crown classes in 6- to 15-year-old stands. Other foliage diseases were responsible for severe defoliation of intermediate and suppressed trees in stands as old as 45 years. Decays of trunks, butts, and roots were present in all stands, including stands of the 6- to 15-year age class. Fungi associated with trunk rots entered mainly through broken trunks and scars. The principal wood-destroying fungus causing trunk decays was Stereum sanguinolentum Alb. and Schw. ex Fr. Fungi associated with root and butt rots of dominant and codominant trees entered mainly through injuries caused by larvae of Hylobius pinicola Couper. This is the first time that H. pinicola has been associated with infection courts of wood-destroying fungi. Injuries of undetermined nature were the principal infection courts of fungi causing root and butt rots of intermediate and suppressed trees. Corticium galactinum (Fr.) Burt was the most frequently isolated Basidiomycete from root and butt rots.

DECAY OF TREMBLING ASPEN

A total of 1754 aspen trees were examined on 47 sample plots located in even-aged stands considered representative of the study area. Decay was found in the merchantable portions of the trunks of 1212 or 69% of these trees. Three types of heart rot were encountered, viz., a white spongy trunk or butt rot and a yellow stringy trunk rot associated respectively with Fomes igniarius var. populinus (Neu.) Campb., and Radulum casearium (Morgan) Lloyd; and stringy butt rots from which several fungi, notably Pholiota spectabilis Fr. and Armillaria mellea (Vahl ex Fr.) Quél., were isolated. Two heartwood stains, one brown and the other mottled red, were present in many of the aspen trees examined. Corticium polygonium Pers. and two members of the Fungi Imperfecti, Libertella sp. and Phialophora alba van Beyma, were consistently isolated from these stains and from incipient decays. Fructifications of F. igniarius were the most reliable external indication of heart rot in this species. A pronounced relationship existed between age and decay. Older stands as a rule contained higher proportions of decayed heartwood than young stands. A less pronounced relationship was found to exist between soil conditions and decay; trees occurring on drier sites were somewhat more decadent than those growing on moist sites. The possible reasons why the decay process in the heartwood of living aspen is one in which certain fungi, mainly Fungi Imperfecti, colonize and stain the wood prior to its invasion and destruction by the Basidiomycetes associated with advanced decay are discussed.

STUDIES IN FOREST PATHOLOGY: XVI. DECAY OF BALSAM FIR, ABIES BALSAMEA (L.) MILL., IN THE ATLANTIC PROVINCES

Analyses of approximately 2600 living balsam fir, examined at seven localities in the Atlantic Provinces, established that, after adjustment for age, differences in the amount of cull existed between some of the localities. The analyses indicated that the effect of age on trees between 60 and 120 years of age is expressed mainly in the number of trees infected with decay, although in some areas it also has an effect on the amount of butt cull in infected trees. Differences in the amount of trunk cull between localities could be attributed to differences in the number of trees possessing this type of decay. No significant effect of age on the amount of trunk cull in infected trees was found in any locality, nor were there any differences in the amount of trunk cull in these trees among localities. Differences in the amount of butt cull were caused both by the number of trees infected with butt rot and by the amount of cull in infected trees. Some factors have been enumerated which require further study before the causes of such differences can be determined. It is felt that a critical study of the infection courts may disclose reasons for differences in the amount of trunk infection. Butt rot relationships appear to be more complex and an understanding of the causes of the variations encountered can be determined only after further intensive studies.

DECAY IN SUBALPINE SPRUCE ON THE ROCKY MOUNTAIN FOREST RESERVE IN ALBERTA

Data from 456 living subalpine spruce on six 0.1-ac. plots in the Bow River Forest in 1950 and six 0.2-ac. plots in the Crowsnest, Bow River, and Clearwater Forests in 1952 show a total of 203 separate infections of which approximately half occurred in the basal part of the trees. Most of the butt rot was associated with Polyporus circinatus var. dualis Peck, Flammula connissans Fr., and an unidentified fungus designated "Unknown C". Coniophora puteana (Schum. ex Fr.) Karst. was the fungus associated with the major portion of the brown butt rot. Among the white trunk rots, Stereum sanguinolentum Alb. & Schw. ex Fr. was the fungus most frequently isolated from infected trees and Fames pint (Thore) Lloyd was responsible for the largest, cull losses. Peniophora septentrionalis Laurila, which was isolated from Picea glauca (Moench) Voss and P. engelmannii Parry, was the third most important fungus associated with trunk rot. Trunk rots account for 70% of the decay losses while fungi producing white rots account for 93.6% of the total decay. The incidence of decay increased progressively with age at different rates for trees on "dry" and "moist" sites. The two sites are characterized by distinctive ground cover associations.

DECAY OF YELLOW BIRCH IN NOVA SCOTIA

A study of the amount and types of decay in yellow birch, Betula lutea Michx. f., in Nova Scotia was undertaken in 1951 and 1952 in order to supply those concerned with information necessary for proper forest management of even-aged stands. A total of 374 trees was examined of which 35% contained some measure of decay. Volume of decay increased with increasing age. Approximately 50% of the trees contained decay at 120 to 130 years of age and 100% at 230 years of age. The loss in merchantable volume increased from a negligible amount at 60 years to about 10% at 240 years. No attempt was made to predict a rotational cut based on diameter. A pathological rotation age of 170 years is suggested for yellow birch in Nova Scotia. Ten wood-destroying fungi were found associated with rot in living trees, five in the butt and five in the trunk. Poria cocos (Schw.) Wulf. caused the most frequent butt rot and Fomes igniarius (L. ex Fr.) Gill. the most common trunk rot.

DECAY IN POPLAR PULPWOOD IN STORAGE

Deterioration of poplar pulpwood (a mixture of Populus tremuloides Michx. and P. balsamifera L.) on Manitoulin Island, Ontario, was studied in field, pit, and block pile storage with reference to the reaction of the rot fungi present in the living tree to storage conditions, and the penetration of fungi which attack wood subsequent to felling. The rots found most prevalent in the living trees, and the most important from the standpoint of volume of wood affected, were the white trunk rots caused by Fomes igniarius var. populinus (Neu.) Campb., Radulum casearium (Morgan) Lloyd, Polyporus dryophilus var. vulpinus (Fr.) Overh., a rot associated with a non-Basidiomycete designated in this paper as Fungus X, and the brown rot produced by Poria cocos (Schw.) Wolf. The first four rots may survive in storage, but are not appreciably active. Butt rots caused by Armillaria mellea (Vahl.) Quél., Pholiota spectabilis (Fr.) Quél., and a gray–brown butt rot were not uncommon, but of limited importance both on account of the amount of wood attacked and the practical inactivity of the causal agents in storage. The only tree-rot fungus found likely to cause damage in storage was P. cocos; it produces brown rot and is capable of spreading vigorously in stored wood. Other tree rots occurred, but were of minor importance. Stereum purpureum Pers. was the first fungus to infect the wood after the trees were felled; it spread rapidly and fruited during the first summer. It was followed by three species of Polyporus, P. adustus (Willd) Fr., P. hirsutus (Wulf.) Fr., and P. versicolor (L.) Fr. These became established in the wood during the first summer; they fruited on field and pit logs during the second season, and were fruiting luxuriantly on block pile logs which had been stored three years. They produce white rots and in some logs caused advanced decay in two years' storage. Other storage rot and staining fungi were isolated from the bolts under study, but during the period of observation did not effect wide spread penetration. The same pattern of decay and succession of fungi were found in all types of storage investigated.

OBSERVATIONS ON ARMILLARIA MELLEA IN IMMATURE DOUGLAS FIR

ARMILLARIA MELLEA (Vahl) Quél., the cause of shoestring root rot, was observed attacking all vigor classes in Douglas fir plantations. In vigorous stock the formation of latent cankers on the roots precluded the active spread of the disease. From these cankers the fungus frequently moved into the woody core causing yellow spongy butt and root rot, which is not fatal to the host. Planting trees on poor sites or with poor technique resulted in severe outbreaks of the disease.

STUDIES IN WOOD-INHABITING HYMENOMYCETES: I. ODONTIA BICOLOR

It has been found by cultural methods that Odontia bicolor (Alb. & Schw. ex Fries) Bres. is the cause of an important butt rot in various species of coniferous and broad-leaved trees in Canada. A description of the cultural characters of the fungus and the decay from which it has been isolated is presented.

NEW INFORMATION CONCERNING BALSAM FIR DECAYS IN EASTERN NORTH AMERICA

Four separate investigations of decay in balsam fir (Abies balsamea (L.) Mill.) have been carried out in recent years by forest pathologists in Eastern North America. Early in these studies it became apparent that the existing ideas concerning the identity of the fungi responsible for decay in living balsam fir trees required considerable revision. Trunk rot was confirmed as being caused mainly by Stereum sanguinolentum Alb. and Schw. ex Fries; however, five fungi, headed by Corticium galactinum (Fries) Burt, were found associated with most of the white stringy butt rots, and two fungi, Coniophora puteana (Schum. ex Fries) Karst. and Polyporus balsameus Peck, were associated with most of the brown cubical butt rots. Hitherto Poria subacida (Peck) Sacc. and P. balsameus were believed to cause practically all white and brown butt rots, respectively, in this species. The effect of site on the decay of living balsam fir is discussed, as is the extent and kind of decay with which each of the nine predominant heart-rot fungi was found associated. A brief outline is presented concerning the fungi found associated with the deterioration of dead balsam fir.

STUDIES IN FOREST PATHOLOGY: VII. DECAY IN WESTERN HEMLOCK AND FIR IN THE FRANKLIN RIVER AREA, BRITISH COLUMBIA

An investigation of decay in western hemlock (Tsuga heterophylla (Raf.) Sarg.) and fir (mainly Abies amabilis (Loud.) Forb.) in the Juan de Fuca forest region of British Columbia has shown that the major organisms causing root and butt rots are the same in both species. These are Poria subacida (Peck) Sacc., Fomes annosus (Fr.) Cke., Armillaria mellea Vahl ex Fr., Polyporus sulphureus Bull. ex Fr., and P. circinatus Fr. Those organisms causing trunk rots of western hemlock, in decreasing order of importance, are Fomes pinicola (Sw.) Cke., F. Pini (Thore) Lloyd, Stereum abietinum Pers., Fomes Hartigii (Allesch.) Sacc. and Trav., and Hydnum sp. (H. abietis). These same organisms causing trunk rots of fir, in decreasing order of importance, are Fomes pinicola, Stereum abietinum, Hydnum sp. (H. abietis), Fomes Pini, and Fomes Hartigii. The logs of 963 western hemlock were analyzed in detail. Maximum periodic volume increment was reached between 225 and 275 years of age. Maximum periodic volume increment was reached between 275 and 325 years of age in the 719 fir that were analyzed. Scars were the most frequent avenue of entrance for infection. In 59% of the cases of infection studied the fungus had entered through wounds.

INVESTIGATIONS OF DECAY IN WESTERN RED CEDAR IN BRITISH COLUMBIA

Investigations of decay in Thuja plicata D. Don. in British Columbia have shown that the major heart-rotting fungi of living western red cedar on the Coast, in decreasing order of importance, are Poria asiatica (Pilát) Overh. (brown cubical pocket and butt rot), Poria albipellucida Baxter (white ring rot), Fomes Pini (Thore) Lloyd (white pitted trunk rot), Merulius sp. (brown crumbly butt rot), and Poria subacida (Peck) Sacc. (spongy white rot). In the Interior of the Province they are Poria asiatica, P. Weirii Murr. (yellow ring rot), Fomes Pini, Polyporus balsameus Peck (brown cubical butt rot), Merulius sp., and Poria subacida. Other fungi attacking the heartwood of living trees less extensively are Fomes annosus (Fr.) Cke., F. nigrolimitatus (Romell) Egel., F. pinicola (Sw.) Cke., Armillaria mellea (Fr.) Quél., Omphalia campanella (Fr.) Quél., Polyporus Schweinitzii Fr., and Coniophora cerebella Pers.On the areas investigated, loss through decay in stands 50 to 450 years of age never exceeded growth increment. It was indicated that decay in younger stands was of importance. Loss through decay and incidence of infection was appreciably higher in the Interior than on the Coast. No reliable external indications of decay in the standing tree were found.Deterioration in felled trees was caused by Poria Weirii, P. albipellucida, P. subacida, Armillaria mellea, Omphalia campanella, Fomes annosus, F. nigrolimitatus, and F. pinicola. Polyporus cuneatus (Murr.) Overh., and Hymenochaete tabacina (Sow.) Lév. were the major decay organisms of cedar sapwood and slash. Polyporus abietinus (Dicks.) Fr., P. versicolor (L.) Fr., P. semipileatus Peck, P. hirsutus (Wulf.) Fr., and Poria isabellina (Fr.) Overh. were restricted in distribution or of irregular occurrence.To assist in the identification of cultures all the major heart-rotting organisms were grown on tannic and gallic acid media. Seventy-seven species of Basidiomycetes were collected on living and dead Thuja plicata in British Columbia from 1943 to 1945.