Phellinus Noxius Research Articles

Oil palm pest infestation monitoring and evaluation by helicopter-mounted, low altitude remote sensing platform

Timely detection of pest or disease infections is extremely important for controlling the spread of disease and preventing crop productivity losses. A specifically designed radio-controlled helicopter mounted low altitude remote sensing (LARS) platform can offer near-real-time results upon user demand. The acquired LARS images were processed to estimate vegetative-indices and thereby detecting upper stem rot (Phellinus Noxius) disease in both young and mature oil palm plants. The indices helped discriminate healthy and infested plants by visualization, analysis and presentation of digital imagery software, which were validated with ground truth data. Good correlations and clear data clusters were obtained in characteristic plots of normalized difference vegetation index (NDVI)LARS and green normalized difference vegetation indexLARS against NDVISpectro and chlorophyll content, by which infested plants were discriminated from healthy plants in both young and mature crops. The chlorophyll content values (μmol m−2) showed notable differences among clusters for healthy young (972 to 1100), for infested young (253 to 400), for healthy mature (1210 to 1500), and for infested mature (440 to 550) oil palm. The correlation coefficients (R2) were in a reasonably acceptable range (0.62 to 0.88). The vegetation indices based on LARS images, provided satisfactory results when compared to other approaches. The developed technology showed promising scope for medium and large plantations.

Cross Inoculation Tests with Phellinus noxius Isolates from Nine Different Host Plants in the Ryukyu Islands, Southwestern Japan.

Brown root rot, caused by Phellinus noxius, leads to problems in management of shade, ornamental, and windbreak trees in subtropical regions of the world, and it has been causing serious problems in Japan since 1988. To identify the pathogenicity, host specialization, and virulence of the pathogen, cross inoculation tests were carried out using isolates of the fungus obtained from nine different tree species. P. noxius was pathogenic to all of the nine tree species tested, and it killed inoculated seedlings. Among the 810 trees inoculated with the fungus, a total of 141 trees (17.4%), including all nine species, were dead within 110 days after inoculation. The first symptom of infection was rapid wilt with discoloration of leaves 20 to 30 days after inoculation, and then the plants quickly declined. Only one isolate of P. noxius that was tested caused significantly higher mortality in its original host than in other species, suggesting that the pathogen has little to no host specificity. However, the fungus did show variation in virulence, with the isolates originating in Bischofia javanica and Casuarina equisetifolia causing significantly higher mortality than those collected from other host species. More isolates of P. noxius from the same host species and/or from various countries should be studied to understand host specialization and virulence of the pathogen.

Evaluation ofOchrobactrum anthropiTRS-2 and its talc based formulation for enhancement of growth of tea plants and management of brown root rot disease

To evaluate Ochrobactrum anthropi TRS-2 isolated from tea rhizosphere and its talc based formulation for growth promotion and management of brown root rot disease of tea. Ochrobactrum anthropi TRS-2, isolated from tea rhizosphere could solubilize phosphate, produce siderophore and IAA in vitro and also exhibited antifungal activity against six test pathogens. Application of an aqueous suspension of O. anthropi to the rhizosphere of nursery grown tea seedlings of five varieties of tea (TV-18, T-17, HV-39, S-449, UP-3 and) led to enhanced growth of the treated plants, as evidenced by increase in height, in the number of shoots and number of leaves per shoot. Treatment with O. anthropi also decreased brown root rot of tea, caused by Phellinus noxius. Multifold increase in activities of chitinase, beta-1,3-glucanase, peroxidase and phenylalanine ammonia lyase in tea plants was observed on application of O. anthropi to soil followed by inoculation with P. noxius. A concomitant increase in accumulation of phenolics was also obtained. Further, talc based formulation of O. anthropi was prepared and its survival determined every month up to a period of 12 months. Ochrobactrum anthropi could survive in the formulation up to a period of 9 months with a concentration of 7.0 log(10) CFU g(-1), after which there was a decline. Talc formulation was as effective as aqueous suspensions in both plant growth promotion and disease suppression. Ochrobactrum anthropi, either in aqueous suspension or as talc formulation induced growth of tea plants and suppressed brown root rot disease. It induced defense responses in tea plants. Ochrobactrum anthropi and its talc based formulation can be considered as an addition to available plant growth promoting rhizobacteria (PGPR) currently being used for field application. The present study offers a scope of utilizing this bacterium for growth promotion and disease management which would help in reduction of the use of chemicals in tea plantations.

First report of the brown root rot disease caused by Phellinus noxius, its distribution and newly recorded host plants in the Amami Islands, southern Japan

SummaryTo determine whether the brown root rot disease caused by Phellinus noxius is present in the Amami islands, which are situated near Okinawa, we conducted six field surveys from 1999 to 2005. The brown root rot disease was found in 22 tree species in 17 plant families at 25 different sites in all the islands surveyed. Sixteen of these species were newly recorded as host plants of P. noxius. The disease was more common in the low elevation plains and on hills less than 100 m above sea level than in mountainous areas. This is the first report of the brown root rot disease caused by P. noxius in the Amami Islands, Japan, and Ohshima Island is currently the northern‐most distribution point of the disease in the northern hemisphere.

Basal Root Rot, a new Disease of Teak (Tectona grandis) in Malaysia caused by Phellinus noxius

Basal root rot of teak was first reported from Sabak Bernam, Selangor making this the first report of the disease on teak in Peninsular Malaysia. The fungus found associated with the disease was Phellinus noxious. The disease aggressively killed its host irrespective of the host health status. Bark depression at the root collar which was visible from a distance was the characteristic symptom and the main indicator in identifying the disease in the plantation since above ground symptoms of the canopy could not be differentiated from crowns of healthy trees. However, although above ground symptoms were not easily discernible, the disease was already advanced and the trees mostly beyond treatment; 3.4 % of the trees in the plantation were affected and the disease occurred both on solitary trees and in patches. Below ground, infected trees had rotted root systems, mainly below and around the collar region with brown discolored wood and irregular golden-brown honeycomb-like pockets of fungal hyphae in the wood. Pathogenicity tests showed that the fungus produced symptoms similar to those observed in the plantation and killed two year-old teak plants. The disease killed all the inoculated hosts within three months, irrespective of wounded or unwounded treatments.

Incidence of teak basal root rot caused byPhellinus noxiusin Malaysia

This is the first report of basal root rot of teak, caused by Phellinus noxius, in Peninsular Malaysia. The disease aggressively killed its host irrespective of health status. Bark depression at the root collar was a very characteristic symptom of this disease on teak and was visible from a distance. Below ground, infected trees had rotted root systems, mainly at the collar region, brown discoloured wood and irregular golden-brown honeycomb-like pockets of fungal hyphae in the roots. Pathogenicity tests showed that the fungus killed 2-year-old teak saplings gradually, producing below- and above ground-symptoms similar to those in the plantation. The disease killed all the infected hosts within 3 months, irrespective of wounded or unwounded treatments. Additional keywords: forest plantation, root disease, teak, Tectona grandis.

Phellinus noxius Brown Root Rot of Fruit and Ornamental Trees in Taiwan.

Phellinus noxius Brown Root Rot of Fruit and Ornamental Trees in Taiwan.

Brown Root Rot Disease in American Samoa's Tropical Rain Forests

Phellinus noxius (Corner) Cunningham causes root and lower stem rot of woody plants throughout the South Pacific region. Its hosts include rubber, mahogany, cacao, and many timber, fruit, and landscape trees. Though endemic to the Tropics, no reports were found describing brown root rot disease in native forests, exclusively. Incidence, distribution, and host range of P. noxius were measured in primary and secondary rain forests on Tutuila Island, American Samoa. Phellinus noxius was recorded in 19 of 20 strip transects and 1.2-ha established plots and in all vegetation types, infecting 37 tree species in 30 genera and 22 families. Species most affected were Myristica fatua, Dysoxylum samoense, and Hibiscus tiliaceusN25, 16, and 10%, respectively. Of 62 infection centers, 33 contained the same tree species and 13 were dominated by a single species. The fewest infections were recorded at primary montane and ridge top sites. Regenerating secondary valley sites had the highest incidence of disease and greatest number of infection centers. Infection centers at these disturbed sites also contained more trees on average than centers at primary sites. Disease incidence was influenced more by human disturbance than by vegetation type, topography, stem diameter, stem density, or soil type. The disturbed sites also appeared to lack the species richness of mature sites. This agrees with other host/pathogen associations, such as Douglas-fir/P. weirii and hardwood/P. noxius plantations, where disease incidence and spread was higher in species-poor than in species-rich stands.

Brown Root Rot of 10 Species of Fruit Trees Caused by Phellinus noxius in Taiwan.

Wilt and death of fruit trees was surveyed from 1990 to 1996. Most trees with decline symptoms in central and southern Taiwan had brown root rot caused by Phellinus noxius. The infected trees included litchi, sugar-apple, plumum, pear, loquat, persimmon, carambola, wax apple, grape, and jellyfig, with ages ranging from young seedlings up to 10-year-old trees. Symptoms were leaf discoloration, unthrifty appearance, and eventual death. Upon inoculation of the roots with P. noxius grown in a wheat-oat medium, healthy seedlings of these 10 tree species were killed. P. noxius was reisolated from diseased tissues of inoculated roots. The isolates of P. noxius obtained from different hosts were similar in morphological characteristics. Host specificity among the tested isolates was not observed in the cross-inoculation test, but variability in virulence was noted in some tests. Mycelial growth of different isolates of P. noxius showed similar temperature response, but the growth rates varied dramatically. Fruiting bodies were rarely found in the field. However, the fungus produced fruiting bodies artificially, on a sawdust medium, that were similar to those produced on the lower stems of declining trees. Brown root rot can be induced by replanting seedlings in infested soil or by contact with the diseased or dead roots. P. noxius causing brown root rot of these 10 fruit trees has not been previously reported.

Generation of volatile ammonia from urea fungicidal to Phellinus noxius in infested wood in soil under controlled conditions

Phellinus noxius was not recovered from pieces of artificially infested wood placed in or on soil amended with urea (NH4)2CO3 or aqueous ammonia. High concentrations of volatile NH3 were detected in these treatments, indicating that NH3 generated from these chemicals was fungicidal to P. noxius. A high concentration of volatile NH3 was detected from nonautoclaved soil amended with urea, but not from amended autoclaved soil, indicating that soil microorganisms were involved in NH3 generation. To kill P. noxius completely required 3000 p.p.m. urea in soil. Volatile NH3 was generated from urea in alkaline soil, but not in acidic soil. In acidic soil 1 month after urea amendment, populations of both fungi and bacteria, and the concentration of NH4+ (but not of NH3 in the air), were significantly greater than in the no urea treatment and in the urea treatment 3 d after amendment, indicating that NH4+, generated from urea in the soil enhanced the activity of soil microorganisms. In contrast, 1 month after amendment of alkaline soil, the concentration of NH4+ in the soil and NH3 in the air increased significantly and the populations of both fungi and bacteria decreased, indicating that NH3 in the air inhibited activity of soil microorganisms. Similar quantities of volatile NH3 were generated at temperatures ranging from 12 to 32°C. A large quantity of NH3 was generated at low soil matric potentials (− 0.75 to − 0.15 MPa) while high potentials (> − 0.025 MPa) and flooded soil hindered production of volatile NH3. Ammonia was more effective at killing P. noxius growing in smaller pieces of wood than in larger pieces. The fungus was not recovered from wood pieces less than 3 cm in diameter. Volatile NH3 was also lethal to six other root rotting fungi (Ganoderma australe, G. lucidum, G. tropicum, Rigidoporus vinctus, Heterobasidion annosum, and Rosellinia necatrix) in addition to P. noxius.

Phellinus noxius in Taiwan: distribution, host plants and the pH and texture of the rhizosphere soils of infected hosts

From 1991 to 1996, Phellinus noxius was collected on 60 host plant species at 136 different sites in Taiwan, and two host plant species at two different sites on Kinmen Island. It was collected mostly on hosts growing in the low elevation plains and hills of western, eastern and southern Taiwan, while it was found on only a few hosts in northern Taiwan and was absent from the high mountain areas. P. noxius was observed on and isolated from 57 woody species, and three annual herbaceous plants. In the field, basidiomes of P. noxius have only been observed on Casuarina equisetifolia, Delonix regia and Ficus microcarpa. A dark brown mycelial mat on the surface of the roots and up the base of stems was used reliably for the field identification of P. noxius. Although P. noxius did not favour a particular soil pH, it was not found in extreme pH conditions. It was found in soils from pH 4 to 9 and most frequently in soil from pH 5 to 8. P. noxius occurred mostly in soils with sand, loamy sand and sandy loam textures.

Distribution of clones of Phellinus noxius in a windbreak on Ishigaki Island

SummaryThe distribution of clones of Phellinus noxius, the causal agent of brown root rot, was studied in a windbreak on Ishigaki Island of Japan. In total, 99 isolates obtained from infected trees of Calopbyllum inophyllum, Casuarina equisetifolia and Bauhinia racemosa were analysed by means of a somatic compatibility test on a sawdust‐rice‐bran medium, an antagonism test on PDA with guaiacol solution, and by esterase analysis with isoelectric focusing. Results obtained from the three methods were almost identical, although the somatic compatibility test was less precise than the other methods. Isolates from neighbouring infected trees belonged to the same clone in many cases. On plots of 150–400 m2, 1–5 clones were found. Single clones covered an area of up to 20 × 20 m. A total or 25 different clones were recognized within the sample sites. This suggested that multiple basidiospore infection existed in the site, although infection centres spread by vegetative growth across root contacts of neighbouring trees.

Modelling rubber‐tree root diseases, simulations of various inoculum rates and methods of control

SummaryTwo root‐rot fungi, Rigidoporus lignosus and Phellinus noxius are the causal agents of severe damage in Ivory Coast rubber tree (Hevea brasiliensis) plantations. Mathematical investigations were made using data from a previous 6 year long epidemiological survey. Modelling of spatial spread of the pathogens and mortality of the infected trees, lead to simulations of the quantitative evolution vs. time of root diseases. The theoretical kinetics obtained revealed intra‐ and interspecific variability among the studied stands with respect to the damage caused. Using this model, different phytosanitary scenarios were simulated in relation to the density of the initial inoculum, the control measures, the specificity of the fungicide, the efficiency of the treatment, and the optimal time for application. Their influence on root‐disease dynamics was quantified. The characteristics of the model, its applicability in plantations and its use in predicting disease or stand development are discussed.

Survival ofPhellinus noxiusin Soil and in the Roots of Dead Host Plants

The survival of Phellinus noxius arthroconidia, basidiospores, and mycelia and of P. noxius-colonized wood was measured in soils with different soil matrix potentials. Survival of arthroconidia declined more slowly in soils with -0.50 and -0.42 MPa of soil matrix potential compared with soils with -0.15 and -0.025 MPa. However, arthroconidia were rarely recovered from the treatments after 3 months. Basidiospores were not recovered after 3, 3.5, 4, and 4.5 months in the -0.025, -0.15, -0.42, and -0.50 MPa soil matrix potential treatments, respectively. Mycelia that were buried in the soil with -0.025 MPa were not recovered after 4 weeks, whereas mycelia in soils with -0.50, -0.42, and -0.15 MPa were not recovered after 10 weeks. P. noxius was not recovered from pieces of artificially infested wood subjected to 1 month of flooding. However, in treatments with lower soil moisture, P. noxius survival ranged from 80% to more than 90% over 2 years. Colonies of P. noxius were not recovered from the rhizosphere of soils around the infested roots of three host species, Calophyllum inophyllum, Casuarina equisetifolia, and Cinnamomum camphora. However, P. noxius was recovered from naturally infected roots of these hosts 1 to 10 years after they were killed. These results indicated that woody debris in soils harboring P. noxius played an important role in the long-term survival of the fungus. Flooding infested fields may help control P. noxius in the field.

A selective medium for Phellinus noxins

SummaryA selective medium was developed for isolation of Phellinus noxius. The medium consists of 20 g/l malt‐extract, 20 g/l agar, 10 mg/l benomyl, 10 mg/l dicloran, 100 mg/l ampicillin and 500 mg/1 gallic acid. For isolation of P. noxius from soils, 1000 mg/l tergitol NP‐7 was added to restrict the size of individual colonies. Comparisons of this selective medium with other media selective for isolation of hymenomycetes showed that the former was more effective for isolation of P. noxius.

Wood degradation by Phellinus noxius: ultrastructure and cytochemistry

An ultrastructural and cytochemical investigation of the development of Phellinus noxius, a white-rot fungus, in wood chips of Betula papyrifera was done to gain insight into the cellular mechanisms of wood cell wall degradation. Extracellular sheaths and microhyphae were seen to be involved in wood colonization. Close association was observed between these fungal structures and wood cell walls at both early and advanced stages of wood alteration. Fungal sheaths were often seen deep inside host cell walls, sometimes enclosing residual wood fragments. Investigations using gold probes indicated the occurrence of β-1,3-glucans within the fungal sheaths, while β-1,4-glucans were detected only within the fungal septa. The positive reaction with the PATAg test revealed that polysaccharides such as β-1,6-glucans were important components of the sheath. Chitin, pectin, β-glucosides, galactosamine, mannose, sialic acid, fucose, and fimbrial proteins were not found to be present in the sheath. Our data suggest that extracellular sheaths and microphyphae produced by P. noxius during wood cell wall colonization play an important role in wood degradation.Key words: cellulose, Phellinus, sheath, wood degradation.

Brown Root Rot of Trees Caused by Phellinus noxius in Windbreaks on Ishigaki Island, Japan. Incidence of Disease, Pathogen and Artificial Inoculation.

Extensive wilts of trees have recently occurred in the windbreaks at Okinawa Branch of the Tropical Agricultural Research Center in Ishigaki Island, Okinawa, Japan. Dead or declined trees were observed at 43 points, the total number of dead and declined trees was over 200 and total length of damaged windbreaks was 515m, in about 11% of the total length of windbreaks. Roots of dead and declined trees were collected and many fungus cultures were isolated from them. Most isolates had the following common cultural characteristics: no clamp connections on septa, staghorn-like hyphae and arthroconidia. Two cultures isolated from tissue of diseased trees were artificially inoculated into saplings of Podocarpus macrophyllus. Nine saplings were killed out of 19 inoculated saplings within 13 months and the fungus was reisolated from the dead saplings. As the isolates were considered to be a hymenomycetous fungus, fungal fruiting bodies were collected from windbreaks and from nearby and cultures were isolated from the collected fruiting bodies. One of cultures isolated from the collected fruiting bodies coincided in cultural characteristics with the isolates from dead and declined trees. The fruiting body from which this culture was isolated, was identified as Phellinus noxius (Corner) Cunningham. Taxonomic study revealed that Ph. sublamaenis (Lloyd) Ryvarden, published as a prior name for Ph. noxius, is a synonym of Ph. lamaensis. The fungus reported as Ph. lamaensis by Yasuda from Bonin Island of Japan in 1916, was identified as Ph. noxius.

Decline of Nine Tree Species Associated with Brown Root Rot Caused byPhellinus noxiusin Taiwan

A decline disease characterized by brown root rot, wilting of foliage, leaf discoloration, a brown mycelial mat growing on roots and stem bases of affected trees, and ultimate death of some trees was found on several tree species growing in the eastern and western coastal regions of central and southern Taiwan. These tree species were mainly growing in landscape plantings rather than in the forest. Species affected by the disease included Acacia confusa, Bauhinia variegata, Calophyllum inophyllum, Casuarina equisetifolia, Ficus microcarpa, Koelreuteria henryi, Podocarpus macrophyllus var. macrophyllus, Salix babylonica, and Swietenia mahagoni. A fungus isolated from diseased tissue produced resupinate, brownish polyporus fruiting bodies on sawdust medium, and was identified as Phellinus noxius. Seedlings of the various host plants found naturally infected in the field were inoculated with P. noxius grown on camphor twig medium. Seedings of all inoculated species were infected, and the fungus was reisolated from diseased tissues. This is the first report of P. noxius on these hosts. In cross pathogenicity tests, isolates of P. noxius from twelve tree species were used to inoculate each of the host species except for the original source of the inoculum. All isolates caused infection on all eleven hosts, indicating that the pathogen does not exhibit host specificity. However, A. confusa and S. babylonica showed lower mortality than other hosts.

Modeling Rubber Tree Root Disease Epidemics with a Markov Spatial Process

Abstract Root diseases of the rubber tree (Hevea Brasiliensis) due to Rigidoporus lignosus (Klotzsch) Imaz. and Phellinus noxius (Corner) G.H. Cunn spread along planting lines and cause serious damage. Various control methods exist. A mathematical model was developed which allows the influence of their various parameters on the dynamics of an epidemic to be evaluated. The health status of the trees on a planting line was considered as a Markov process. The model parameters were given a biological interpretation and estimated using the results of an epidemiological survey carried out in Côte d'Ivoire from 1977 to 1984. Hypotheses of influence of dead trees before the survey, stationarity of secondary infection, and development of initial infection were tested. By simulation of the main model, the parameters were linked to percentages of infected trees on each inspection and of healthy trees at the end of the epidemic, thereby allowing the effects of the control methods to be evaluated according to their nature, efficiency, and mode of application. FOR. SCI. 39(1):41-54.

New developments in chemical control of white root disease of Hevea brasiliensis in Africa

The main three parasites on Hevea brasiliensis roots in Africa are Rigidoporus lignosus, Phellinus noxius and Armillaria sp. Only R. lignosus, which causes white root disease, exists in all the Hevea-growing zones and remains the main cause of death throughout African countries. New fungicides have been tested to improve the control of white root disease caused by R. lignosus. Some of the triazole compounds have proved very effective in vitro and in small-scale experiments on seedlings or stumps placed in artificially infected soil. Two applications spaced 6 months apart in liquid form (Alto, Sandoz) or triadimenol applications in granular form (Bayfidan, Bayer) at 0.5 g a.i. per tree, have given good results in field trials. Their use is recommended in practice.