Collar Area Research Articles

Environmental Scanning Electron Microscopy of the Infection Process of Fusarium solani f. sp. passiflorae in Seedlings of Passionfruit (Passiflora edulis f. flavicarpa)

Se realizó microscopía electrónica de barrido ambiental (ESEM) en plántulas de maracuyá (Passiflora edulis f. flavicarpa) inoculadas con Fusarium solani f. sp. passiflorae (teleomorfo: Haematonectria haematococca) agente causal de la secadera. Las inoculaciones se realizaron cada 24 h hasta el séptimo día y hasta el día quince el intervalo fue de 72 h. El aislamiento en medio de papa (PDA) se colocó sobre el cuello de la raíz mediante la metodología de cribado en tubos de ensayo modificada. La superficie del cuello, tallo, hojas y secciones longitudinales del cuello y tallo fueron observadas. Después de 24 h de la inoculación, se observaron conidios y micelio denso septado sobre la epidermis del tallo y el cuello e hipertrofia y degradación de la pared celular de los tejidos vasculares. Al quinto día se formaron macroconidios a partir de monofiálides en el micelio aéreo en el tallo. Diez días después, las células del xilema y médula del cuello fueron colonizadas por hifas, esporodoquios maduros e inclusiones. La colonización de las estomas por las hifas comenzó seis días después de la inoculación y trece días después de la inoculación se observaron monofiálides con microconidios in situ sobre la superficie foliar. Basados en la evidencia y estudios previos, la colonización interna por hifas de F. solani f. sp. passiflorae se concentra en el área del cuello y los daños de las células indican una actividad enzimática extracelular del hongo. El periodo de incubación y latencia de F. solani f. sp. passiflorae fue de 1,4 y 4 días, respectivamente. © 2017. Acad. Colomb. Cienc. Ex. Fis. Nat.

Reaction of Solanum (section Lycopersicon) germplasm to Phytophthora capsici

The use of resistant cultivars is one of the most efficient strategies for reducing the amount of pesticides in agricultural crops. Several species of the Solanaceae and Cucurbitaceae families are susceptible to diseases caused by Phytophthora capsici isolates. Even though sources of resistance have been identified in other host plants, reports of resistance to P. capsici in cultivated and wild tomato species [genus Solanum (section Lycopersicon)] germplasm are yet scarce. The main objective of the present work was to characterize the reaction of 244 Solanum (Lycopersicon) accessions to P. capsici under controlled greenhouse experiments. In the first set of experiments, tomato seedlings were inoculated at the collar area with a 3 mL of a spore suspension (2 × 104 zoospores mL−1). Disease incidence (dead plants/total plants) was assessed 14 days after inoculation. The accessions were separated in five well-defined reaction groups: highly resistant (HR), resistant (R), moderately susceptible (MR), susceptible (S), and highly susceptible (HS). The reaction of a group of the ten accessions with the highest levels of resistance was then evaluated against a collection of five P. capsici isolates. Differential reaction was observed among accessions and isolates. The resistant response was host species-dependent with susceptibility being more often found in S. peruvianum accessions, whereas sources of resistance were identified more frequently among accessions of the cultivated tomato (S. lycopersicum).

Titanium posts and bonded amalgam core longevity: A 22-year clinical survival retrospective study

BackgroundThe authors conducted a retrospective study to evaluate the long-term (18-22 years) clinic results of titanium post and bonded amalgam core restorations with metal-ceramic crowns placed in patients. MethodsFrom 1992 through 1996, the authors placed 88 restorations in 66 patients. They measured the ferrule effect in the minor dentin collar area. In 2014, the authors analyzed the following variables: ferrule length, length and thickness of the post, and tooth position. ResultsThe overall survival of the restorations decreased over time with survival rates of 89.6% after 5 years of follow-up appointments and 64.2% after 18 years of follow-up appointments. There were 42 failures, and the maxillary premolars had the most failures. The teeth with 2 or more millimeters ferrule length had a higher survival rate than those with a 0 to less than 2 mm ferrule length; these results were not statistically significant. ConclusionsStatistically significant differences were detected according to the location of the tooth. The cores in the anterior teeth were 3.26 times more likely to fail than those in the molars, which presented higher survival rates; maxillary premolars had the most failures (28.5%). Both the metallic post length and its diameter did not influence restoration survival. The ferrule length was not statistically significant. Practical ImplicationsThe clinical technique to restore endodontically treated teeth that includes a titanium post and bonded amalgam restorations results in greater coronal destruction but shows good long-term results, ease of fabrication, and modest cost in comparison with other techniques.

Controlling Honey Locust (Gleditsia triacanthos) with Cut Stump- and Basal Bark-Applied Herbicides for Grazed Pasture

Honey locust is a deciduous tree that is now present throughout most of the United States. Fire suppression and introduction of honey locust into shelter belts has allowed honey locust to increase in pastures of mixed grass prairie. Because locust trees can produce abundant sprouts, mechanical measures also require herbicides to effectively control trees. Each year for 2 yr, trees were treated with one of five combinations of herbicides and application methods. Treatment combinations, on a v/v basis, included (1) triclopyr 25% + diesel 75% and (2) aminopyralid 5% + bark oil 95%, both applied to the lower 38 cm of basal bark including the root collar area of live trees, as well as (3) triclopyr 25% + diesel 75%, (4) aminopyralid 10% + water 90%, and (5) dicamba 33% + 2,4-D 2% + water 65%, all applied immediately to the outer cambium layer of cut stump surfaces. One year after treatment, aminopyralid applied as a basal bark or as a cut-tump treatment had the best control and averaged over 97% dead trees. The triclopyr + diesel cut-stump treatment had the fewest dead trees (just over 50%) and produced many new sprouts. In grazed pasture, treating cut tree surfaces with dicamba + 2,4-D + water or aminopyralid + water and treating standing live trees with a basal bark application of aminopyralid + oil are three effective control options. Triclopyr + diesel displayed better control on live standing trees with a basal bark treatment rather than as a cut-stump treatment.

THE GOLD AND GARNET CHAIN FROM ISENBÜTTEL, GERMANY: A POSSIBLE PIN SUITE WITH ANGLO-SAXON PARALLELS

The ‘Isenbüttel gold necklace’, now in the Lower Saxony State Museum in Hanover, was found almost a century ago in Lower Saxony, an area with no history of early medieval gold finds or richly furnished burials. As no parallels are known for the object, scholars have long debated the dating, provenance and function of this unique loop-in-loop chain, with its animal-head terminals and garnet cloisonné. Recent excavations of Anglo-Saxon cemeteries dating to the seventh century have, however, added new finds to the small corpus of objects known as ‘pin suites’, consisting of comparatively short pins perhaps designed to fix a veil or a light shawl in the collar area, with ornate pinheads, linked by chains. This paper focuses on Anglo-Saxon pin suites from high-status burials of the second half of the seventh century and seeks to set the finds group in its wider social and historical context, revealing the far-reaching relationships that existed between early medieval elites.

Influence of site and stand factors on Hymenoscyphus fraxineus‐induced basal lesions

Hymenoscyphus fraxineus is an invasive fungus in Europe and causes a severe decline affecting ash, which began in the late 1990s. One of the symptoms associated with the disease is lesions in the outer bark of the collar area. However, the aetiology of these basal lesions, and in particular the relative roles of H. fraxineus and Armillaria species, is still controversial; moreover, little is known about the influence of environmental factors on the disease epidemiology. This study therefore surveyed 42 plots located in northeastern France, in an area affected by ash decline since 2008, in order to determine which environmental factors condition the severity of lesions associated with H. fraxineus on ash collar. The spatial pattern that is a consequence of the invasive spread of the disease was taken into account in the analysis, using a spatial hierarchical Bayesian model fitted by integrated nested laplace approximation (INLA). Results show that while basal lesions are tightly associated with H. fraxineus, their severity is influenced by the Armillaria species present in the plot. Sites with vegetation indicating moist conditions, or more humid topographical positions, were associated with more developed basal lesions.

English

Soil fungi, Fusarium oxysporum FO and F. solani FS (teleomorph: Nectria hematococca), are pathogens of economic importance passion fruit crops. The present work was developed in order to standardize the methodology of inoculation, as an initial step to confirm the etiology of diseases associated with Fusarium wilt and collar rot. Strains of FO for A14, A16, A22, A27, A29, A32, A34, A48, A54, A64 and FS A11, A23, A62, A63 were used; they were obtained from symptomatic crops of P. edulis. Inoculations were carried with and without wounds, on seedlings of two and four months of P. edulis. To assess incidence and severity, a scale designed for symptoms and growth variables was used. An incubation period of 14 to 19 days for FO, and was found highly virulent strains (A54, A64, A34). The symptoms are characterized by vascular wilt corresponded to a pattern of descending necrosis. Cross sections showed discoloration in vascular vessels and roots showed necrotic processes that lead to delayed development of seedlings. FS causes disease but the evolution in most strains is very low and exceeds 100 days. Wounds are further evidence for the fungus required in the plant tissue. Symptoms are manifested in the collar area with redness, mild canker associated with cracking and dry appearance on the injury.   Key words: Pathogenicity, collar rot, Fusarium wilt, passion flower, Passiflora edulis, Koch´s postulates.

Two Implant/Abutment Joint Designs: A Comparative Finite Element Analysis

The aim of this study was to compare the influence of abutment screw preload on the marginal bone stress around a conventional external-hex implant system and one with a new implant/abutment joint design. Two implant/bone models, each consisting of three parts and fabricated of titanium and bone (cortical), were built and arranged with computer-aided design software. The first model represented an external-hex implant system, while the second had a tapered extension over the external hex, 1.5 mm high, so that the apical extension of the abutment screw in the assembly did not go beyond the lower level of the implant shoulder. Meshing and generation of boundary conditions, loads, and interactions were performed for the two models. All parts were meshed independent of each other. The sole load applied on the model was a torque of 32 Ncm on the abutment screw about its axis of rotation. The first model showed deformation of the implant collar, and the resulting von Mises stress was 60 MPa in the marginal bone. In contrast, no deformation was observed in the second model. The new implant/abutment joint eliminated the deformation at the implant collar area caused by the application of tightening torque and thus eliminated the resulting stresses in the marginal bone.

Ultrastructure and function of stalks of the diatom Didymosphenia geminata

One of the most striking features of the diatom Didymosphenia geminata, which has increased markedly in abundance in a number of countries in recent years, is the very large branched stalks. In order to help understanding their role, an ultrastructural study was carried out on two populations, one from a stream in northern England and the other from a river on Vancouver Island, Canada. In both cases, the main part of the stalk had a central reticulate core surrounded by an outer region with dense fibres. A longitudinal structure in the uppermost part of the stalk just under the collar surrounding the base of the cell may perhaps correspond to a tube. The structure of the septa formed where branches divide is also described. Phosphomonoesterase activity known to be present in the stalks was shown to occur in the inner peripheral layers of the stalks and especially in the collar area. The results show that stalks have a complex structure suggesting their importance for their phosphatase activity to overcome low inorganic phosphate concentrations. Their large surface may function in herbivory avoidance, a better exposure of cells to turbulent conditions to increase nutrient uptake, adsorption of limiting elements and gas exchange.

Relations between the air/wine adsorption layer and the bubble collar stability in experimental and commercial champagnes

A bubble collar is expected on a champagne flute. The mechanisms of formation of that collar have been tackled, by an integrated approach including the analysis of the adsorption layer occurring at the air/champagne interface, the measurement of the lifetime of isolated air bubbles blown in degassed champagne and the kinetics of the area covered by the collar after pouring in a flute. In the case of experimental champagnes where the surface concentration of the adsorption layer is varied, very good correlations were observed between the adsorption layer parameters, the lifetime of isolated bubbles and the kinetics of the collar area. These correlations were expected from the physics of bubbles and foams. The same parameters were determined on commercial samples bought in supermarkets. The adsorption layer concentrations were found to be in the same range as those of the experimental products, the lifetimes of isolated bubbles were often shorter and the area of the collar was much less stable than with the experimental samples. Moreover, with the commercial samples, no correlations were noticed between the measured parameters. It is hypothesised that the main differences between the experimental and the commercial samples come from the wine making technologies including the ageing on lees and in bottle.

Ring around the collar area

Ring around the collar area

Disposition of rainwater under creosotebush

AbstractIn desert shrubland ecosystems water and nutrients are concentrated beneath shrub canopies in ‘resource islands’. Rain falling on to these islands reaches the ground as either stemflow or throughfall and then either infiltrates into the soil or runs off as overland flow. This study investigates the partitioning of rainwater between stemflow and throughfall in the first instance and between infiltration and runoff in the second.Two series of 40 rainfall simulation experiments were performed on 16 creosotebush shrubs in the Jornada Basin, New Mexico. The first series of experiments was designed to measure the surface runoff and was performed with each shrub in its growth position. The second series was designed to measure stemflow reaching the shrub base and was conducted with the shrub suspended above the ground. The experimental data show that once equilibrium is achieved, 16% of the rainfall intercepted by the canopy or 6·7% of the rain falling inside the shrub area (i.e. the area inside the shrub's circumscribing ellipse) is funnelled to the shrub base as stemflow. This redistribution of the rainfall by stemflow is a function of the ratio of canopy area (i.e. the area covered by the shrub canopy) to collar area (i.e. a circular area centred on the shrub base), with stemflow rate being positively correlated and throughfall rate being negatively correlated with this ratio.The surface runoff rate expressed as a proportion of the rate at which rainwater arrives at a point (i.e. stemflow rate plus throughfall rate) is the runoff coefficient. A multiple regression reveals that 75% of the variance in the runoff coefficient can be explained by three independent variables: the rainfall rate, the ratio of the canopy area to the collar area, and the presence or absence of subcanopy vegetation. Although the last variable is a dummy variable, it accounts for 66·4% of the variance in the runoff coefficient. This suggests that the density and extent of the subcanopy vegetation is the single most important control of the partitioning of rainwater between runoff and infiltration beneath creosotebush. Although these findings pertain to creosotebush, similar findings might be expected for other desert shrubs that generate significant stemflow and have subcanopy vegetation. Copyright © 2003 John Wiley & Sons, Ltd.

Whorl and pollen‐shed stage application of Beauveria bassiana for suppression of adult western corn rootworm

AbstractThe corn rootworm complex is the most damaging insect pest of corn (Zea mays L.). This study was conducted to determine the efficacy of whorl and pollen‐shed stage applications of a granular formulation of Beauveria bassiana (Balsamo) Vuillemin for control of adult western corn rootworm (Diabrotica virgifera virgifera Le Conte). The effect of application time (whorl‐stage, pollen‐shed) and plant surface exposed (leaves and leaf collars; silks; leaves, leaf collars, and silks) on level of beetle fungal infection were investigated. In addition, the number of colony forming units of B. bassiana in the corn leaf collar area was quantified. In the three years (1998–2000) of the study, application of B. bassiana at whorl‐stage did not significantly increase beetle fungal infection. Beauveria bassiana applied to plants at pollen‐shed in 1998 resulted in a significant increase in beetle infection with 51% of beetles from treated plants infected and 6.0% from control plants. Similar applications at pollen‐shed in 1999 and 2000 resulted in very low infection levels. Beauveria bassiana application at pollen‐shed stage significantly increased the number of colony forming units per leaf collar during all years of the study. Beetle infection with B. bassiana did not differ consistently among plant surface to which beetles were exposed for either application. Increased fungal load in leaf collars was not correlated with increased levels of adult infection. Increased rates of B. bassiana and application when beetles are present on the plants are likely needed to significantly increase infection rates.

Sexual selection of multiple handicaps in the red-collared widowbird: female choice of tail length but not carotenoid display.

Although sexual selection through female choice explains exaggerated male ornaments in many species, the evolution of the multicomponent nature of most sexual displays remains poorly understood. Theoretical models suggest that handicap signaling should converge on a single most informative quality indicator, whereas additional signals are more likely to be arbitrary Fisherian traits, amplifiers, or exploitations of receiver psychology. Male nuptial plumage in the highly polygynous red-collared widowbird (Euplectes ardens) comprises two of the commonly advocated quality advertisements (handicaps) in birds: a long graduated tail and red carotenoid coloration. Here we use multivariate selection analysis to investigate female choice in relation to male tail length, color (reflectance) of the collar, other aspects of morphology, ectoparasite load, display rate, and territory quality. The order and total number of active nests obtained are used as measures of male reproductive success. We demonstrate a strong female preference and net sexual selection for long tails, but marginal or no effects of color, morphology, or territory quality. Tail length explained 47% of male reproductive success, an unusually strong fitness effect of natural ornament variation. Fluctuating tail asymmetry was unrelated to tail length, and had no impact on mating success. For the red collar, there was negative net selection on collar area, presumably via its negative relationship with tail length. None of the color variables (hue, chroma, and brightness) had significant selection differentials, but a partial effect (selection gradient) of chroma might represent a color preference when tail length is controlled for. We suggest that the red collar functions in male agonistic interactions, which has been strongly supported by subsequent work. Thus, female choice targets only one handicap, extreme tail elongation, disregarding or even selecting against the carotenoid display. We discuss whether long tails might be better indicators of genetic quality than carotenoid pigmentation. As regards the evolution of multiple ornaments, we propose that multiple handicap signaling is stable not because of multiple messages but because of multiple receivers, in this case females and males.

SEXUAL SELECTION OF MULTIPLE HANDICAPS IN THE RED-COLLARED WIDOWBIRD: FEMALE CHOICE OF TAIL LENGTH BUT NOT CAROTENOID DISPLAY

Although sexual selection through female choice explains exaggerated male ornaments in many species, the evolution of the multicomponent nature of most sexual displays remains poorly understood. Theoretical models suggest that handicap signaling should converge on a single most informative quality indicator, whereas additional signals are more likely to be arbitrary Fisherian traits, amplifiers, or exploitations of receiver psychology. Male nuptial plumage in the highly polygynous red-collared widowbird (Euplectes ardens) comprises two of the commonly advocated quality advertisements (handicaps) in birds: a long graduated tail and red carotenoid coloration. Here we use multivariate selection analysis to investigate female choice in relation to male tail length, color (reflectance) of the collar, other aspects of morphology, ectoparasite load, display rate, and territory quality. The order and total number of active nests obtained are used as measures of male reproductive success. We demonstrate a strong female preference and net sexual selection for long tails, but marginal or no effects of color, morphology, or territory quality. Tail length explained 47% of male reproductive success, an unusually strong fitness effect of natural ornament variation. Fluctuating tail asymmetry was unrelated to tail length, and had no impact on mating success. For the red collar, there was negative net selection on collar area, presumably via its negative relationship with tail length. None of the color variables (hue, chroma, and brightness) had significant selection differentials, but a partial effect (selection gradient) of chroma might represent a color preference when tail length is controlled for. We suggest that the red collar functions in male agonistic interactions, which has been strongly supported by subsequent work. Thus, female choice targets only one handicap, extreme tail elongation, disregarding or even selecting against the carotenoid display. We discuss whether long tails might be better indicators of genetic quality than carotenoid pigmentation. As regards the evolution of multiple ornaments, we propose that multiple handicap signaling is stable not because of multiple messages but because of multiple receivers, in this case females and males.Corresponding Editor: P. Dunn

Bacterial colonization of barrier material and periodontal regeneration.

The objective of this study was to evaluate the relationship between the presence of bacteria on the tooth-facing surface of ePTFE barriers and the clinical outcome of membrane supported reconstructive periodontal surgery. 20 systemically healthy subjects affected by chronic periodontitis were enrolled. One tooth site per patient, associated with an angular bony defect and a probing attachment loss of > 4 mm, was selected to be treated by means of a guided tissue regeneration procedure using an ePTFE barrier membrane. Antibiotics (Augmentin 1 g/day) for 2 weeks were prescribed. In addition to the use of chlorhexidine for post-surgical plaque control, all patients were recalled once a week for professional tooth cleaning. The barrier material was harvested for SEM analysis after 4-6 weeks. Professional tooth cleaning and reinforcement of sel-performed oral hygiene measures were given at 1 mouth intervals after membrane removal. For each treated site, the difference in probing attachment loss between baseline examination and a follow-up examination after 6 months of healing was calculated. The results of the SEM-analysis revealed that bacterial colonization was evident in the collar area of all the retrieved membranes. In the mid part of the membranes 30 out of 60 microscopic fields (50%) demonstrated microbial colonization, and in the most apical part 9 out of 60 fields (15%). Regression analysis indicated that gain in probing attachment level was positively correlated to initial attachement loss and negatively correlated to microbial colonization of the mid part of the membranes. It was concluded that bacterial colonization in the mid part of the ePTFE membrane reduced the potential gain in probing attachment following GTR-therapy with almost 50%.

“I want to do something better”: Career education, guidance and counselling for young women wtth disabilities in secondary schools

This paper is based on our studySchool subjects, tertiary education, career choice and occupational outcomes: A study of women with sensory and physical disabilities(van Kraayenoord & Bramley, 1993). First, we discuss the literature related to subject selection at high school. The second part of the article examines factors that assist or hinder career choice and development. These factors include specific career aspirations, parents, teachers, career counsellors and gender stereotyping. In the third section of the article we describe the continuum of career education, guidance and counselling that we believe would assist in career decision making if developed in schools. The fourth part of the article makes some specific suggestions related to the nature of assistance that young women with disabilities in secondary school need as part of the process of developing knowledge about work and careers. We argue that changes in practices and attitudes in high schools related to career information and support provided to young women with disabilities will lead to better planned and more effective career paths for these women in the long term.When I was at school, one of the career teachers thought I should … work in the blue collar area, not the white collar area … [and said] ‘No you can't do that’ … I really wanted that too much. I wanted something better. I couldn't argue though. Now I hope that the teacher sees what I am now. Be surprised, perhaps shrink down, realise that she had the wrong thought (van Kraayenoord & Bramley, 1993, p.68.)

Exit block in pediatric cardiac pacing: Comparison of the suture-type and fishhook epicardial electrodes

Ninety-seven consecutive permanent epicardial pacemaker implantations were performed with either suture-type (group I, n = 52) or fishhook electrodes (group II, n = 45). In addition to epicardial fixation of the electrodes at the collar area, the suture-type was further secured in place by tying the electrode's suture at its exit to another nonabsorbable pledget-supported suture. Acute thresholds and slew rates were not significantly different between the two groups. Although the R wave was lower in group I (8.4 +/- 3.5 mV) than in group II (11.8 +/- 6, p less than 0.01), no sensing problems occurred. The larger surface area of suture-type electrode led to lower resistance in group I (271 +/- 61 omega) compared with group II (356 +/- 72, p less than 0.001); however, the difference in pacemaker generator longevity did not appear significant (group I, n = 12, mean 4.7 +/- 1.6 years; group II, n = 4, mean 5 +/- 0.6 years). The incidence of exit block was significantly higher in group II (40%, 18/45) than in group I (8%, 4/52, p less than 0.01). The length of the stimulation tip and better fixation of the suture-type electrode probably accounted for the observed difference in the incidence of exit block between the two electrodes.

Effects of Bud Demography and Elongation Patterns on Betula Cordifolia Near the Tree Line

Because plants acquire their structure through the activity of their meristems, whether meristems die, remain dormant, multiply, or develop inflorescences has distinct morphological implications. Studies of bud demography have the potential to explain the form of many temperate—zone trees. In this paper, I present field data collected on tree—line mountain white birches (Betula cordifolia Regel) whose buds were censused over a period of 1—3 yr. Birches ranged in shape from fully erect trees (7—8 m tall) in sheltered forest sites, to low polycormic shrubs (< 1 m tall) in nearby exposed tundra sites. Three questions were asked. (1) Is size merely an expression of age? (2) Is shoot elongation limited by (a) environmental factors, (b) low levels of meristematic activity, or (c) excessive allocation to reproduction? (3) Do bud and branch mortality vary from site to site? If so, is that variation a result of (a) herbivory or (b) climatic factors? Reproduction and browsing were not significant factors contributing to the reduced size of tundra birches. These birches however, did produce smaller long shoots and suffered heavier bud mortality during winter than birches at the other sites, with important year—to—year fluctuations, and thus parts of questions 2a and 3b were answered. After exposure to an extreme winter, most birches can resprout from dormant buds in the root collar area and form polycormic individuals. Both the frequency and severity of winter injury were related to the degree of exposure to the elements, and appear to be key factors in the morphogenesis of tree—line birches.

Growth and ectomycorrhizal development of Pinus caribaea seedlings inoculated with basidiospores of Scleroderma dictyosporum in fertilized nursery soil in Tanzania

Seeds of Pinus caribaea were sown in plastic pots containing nursery soil with or without a basidiospore inoculum of Scleroderma dictyosporum. After seedling establishment, five fertilizer treatments involving 0, 250, 500, 750 and 1000 g NPK per m 3 of nursery soil were administered. The ratio of N:P:K in NPK was 3:3:1. Basidiospores of S. dictyosporum were an effective inoculum for P. caribaea seedlings. Inoculated seedlings showed superior growth in height, root collar area, length of stem with needles and dry matter production. Inoculation also increased the concentration of P in the plant tissues but had no effect on other nutrients studied. Fertilizer response was evident, but there were generally no benefits of using fertilizer levels above 250 g NPK per m 3 soil. In fact, mycorrhizal development was progressively reduced with each increase in the level of NPK fertilizer. Tissue Mg concentrations were also deficient, a reflection of nutrient uptake imbalance due to high concentrations of ammonium sulphate and potassium chloride in the soil. Basidiospores of S. dictyosporum can therefore be used for routine inoculation of P. caribaea seedlings in nursery soils at low levels of NPK. Coincidentally such a reduction in the amount of NPK applied in nursery soil will have both biological as well as economic benefits.