A tool box for operational mosquito larval control: preliminary results and early lessons from the Urban Malaria Control Programme in Dar es Salaam, Tanzania

Background

As the population of Africa rapidly urbanizes, large populations could be protected from malaria by controlling aquatic stages of mosquitoes if cost-effective and scalable implementation systems can be designed.

Methods

A recently initiated Urban Malaria Control Programme in Dar es Salaam delegates responsibility for routine mosquito control and surveillance to modestly-paid community members, known as Community-Owned Resource Persons (CORPs). New vector surveillance, larviciding and management systems were designed and evaluated in 15 city wards to allow timely collection, interpretation and reaction to entomologic monitoring data using practical procedures that rely on minimal technology. After one year of baseline data collection, operational larviciding with Bacillus thuringiensis var. israelensis commenced in March 2006 in three selected wards.

Results

The procedures and staff management systems described greatly improved standards of larval surveillance relative to that reported at the outset of this programme. In the first year of the programme, over 65,000 potential Anopheles habitats were surveyed by 90 CORPs on a weekly basis. Reaction times to vector surveillance at observations were one day, week and month at ward, municipal and city levels, respectively. One year of community-based larviciding reduced transmission by the primary malaria vector, Anopheles gambiae s.l., by 31% (95% C.I. = 21.6–37.6%; p = 0.04).

Conclusion

This novel management, monitoring and evaluation system for implementing routine larviciding of malaria vectors in African cities has shown considerable potential for sustained, rapidly responsive, data-driven and affordable application. Nevertheless, the true programmatic value of larviciding in urban Africa can only be established through longer-term programmes which are stably financed and allow the operational teams and management infrastructures to mature by learning from experience.     

Weather-based prediction of Plasmodium falciparum malaria in epidemic-prone regions of Ethiopia I. Patterns of lagged weather effects reflect biological mechanisms

Background

Introducing sustainability and self-reliance is essential in chronic humanitarian emergencies before financial assistance is phased out. In Pakistan-based Afghan refugee camps, this was attempted through shifting from indoor residual spraying (IRS) to the subsidized sale of insecticide-treated nets (ITNs) for prevention of malaria and anthroponotic cutaneous leishmaniasis (ACL). Here we outline the strategy and document the progress to provide guidance for replication of similar approaches in other chronic refugee situations.

Methods

The operational monitoring data presented were collected through: (i) two surveys of knowledge, attitude and practice (KAP); (ii) routine sales reporting of health-care providers; (iii) records completed during field visits; and (iv) registers used during annual re-treatment campaigns.

Results

From 2000 until 2003, subsidized ITN sales expanded from 17 to 44 camps. Based on 2003 sales records, maximum coverage from subsidized sales exceeded 50% in 13 camps and 20% in an additional 14 camps. Free annual treatment campaigns showed that many refugees were in possession of non-programme nets, which were either locally-made or had leaked from an ITN programme in Afghanistan. Estimated re-treatment coverage of sold and existing nets through annual campaigns exceeded 43% in all camps and was above 70% in the majority.

Conclusion

Subsidized sales of ITNs have effectively introduced the components of sustainability and self-reliance to the prevention of malaria and ACL in Afghan refugee camps. Similar approaches should be investigated in other chronic refugee situations to discourage expectations of continuing humanitarian donations that cannot be fulfilled.     

Increasing coverage of insecticide-treated nets in rural Nigeria: implications of consumer knowledge, preferences and expenditures for malaria prevention

Background

The coverage of insecticide-treated nets (ITNs) remains low despite existing distribution strategies, hence, it was important to assess consumers' preferences for distribution of ITNs, as well as their perceptions and expenditures for malaria prevention and to examine the implications for scaling-up ITNs in rural Nigeria.

Methods

Nine focus group discussions (FGDs) and questionnaires to 798 respondents from three malaria hyper-endemic villages from Enugu state, south-east Nigeria were the study tools.

Results

There was a broad spectrum of malaria preventive tools being used by people. The average monthly expenditure on malaria prevention per household was 55.55 Naira ($0.4). More than 80% of the respondent had never purchased any form of untreated mosquito net. People mostly preferred centralized community-based sales of the ITNS, with instalment payments.

Conclusion

People were knowledgeable about malaria and the beneficial effects of using nets to protect themselves from the disease. The mostly preferred community-based distribution of ITNs implies that the strategy is a potential untapped additional channel for scaling-up ITNs in Nigeria and possibly other parts of sub-Saharan Africa.     

Invasion of Ureaplasma diversum in Hep-2 cells

Background

Mozambique is one of the countries with the highest burden of tuberculosis (TB) in Sub-Saharan Africa, and information on the predominant genotypes of Mycobacterium tuberculosis circulating in the country are important to better understand the epidemic. This study determined the predominant strain lineages that cause TB in Mozambique.

Results

A total of 445 M. tuberculosis isolates from seven different provinces of Mozambique were characterized by spoligotyping and resulting profiles were compared with the international spoligotyping database SITVIT2. The four most predominant lineages observed were: the Latin-American Mediterranean (LAM, n = 165 or 37%); the East African-Indian (EAI, n = 132 or 29.7%); an evolutionary recent but yet ill-defined T clade, (n = 52 or 11.6%); and the globally-emerging Beijing clone, (n = 31 or 7%). A high spoligotype diversity was found for the EAI, LAM and T lineages.

Conclusions

The TB epidemic in Mozambique is caused by a wide diversity of spoligotypes with predominance of LAM, EAI, T and Beijing lineages.     

Multi-centre cluster randomised trial comparing a community group exercise programme with home based exercise with usual care for people aged 65 and over in primary care: protocol of the ProAct 65+ trial

Background

Earlier diagnosis followed by multi-factorial cardiovascular risk intervention may improve outcomes in Type 2 Diabetes Mellitus (T2DM). Latent phase identification through screening requires structured, appropriately targeted population-based approaches. Providers responsible for implementing screening policy await evidence of clinical and cost effectiveness from randomised intervention trials in screen-detected T2DM cases. UK South Asians are at particularly high risk of abnormal glucose tolerance and T2DM. To be effective national screening programmes must achieve good coverage across the population by identifying barriers to the detection of disease and adapting to the delivery of earlier care. Here we describe the rationale and methods of a systematic community screening programme and randomised controlled trial of cardiovascular risk management within a UK multiethnic setting (ADDITION-Leicester).

Design

A single-blind cluster randomised, parallel group trial among people with screen-detected T2DM comparing a protocol driven intensive multi-factorial treatment with conventional care.

Methods

ADDITION-Leicester consists of community-based screening and intervention phases within 20 general practices coordinated from a single academic research centre. Screening adopts a universal diagnostic approach via repeated 75g-Oral Glucose Tolerance Tests within an eligible non-diabetic population of 66,320 individuals aged 40-75 years (25-75 years South Asian). Volunteers also provide detailed medical and family histories; complete health questionnaires, undergo anthropometric measures, lipid profiling and a proteinuria assessment. Primary outcome is reduction in modelled Coronary Heart Disease (UKPDS CHD) risk at five years. Seven thousand (30% of South Asian ethnic origin) volunteers over three years will be recruited to identify a screen-detected T2DM cohort (n = 285) powered to detected a 6% relative difference (80% power, alpha 0.05) between treatment groups at one year. Randomisation will occur at practice-level with newly diagnosed T2DM cases receiving either conventional (according to current national guidelines) or intensive (algorithmic target-driven multi-factorial cardiovascular risk intervention) treatments.

Discussion

ADDITION-Leicester is the largest multiethnic (targeting >30% South Asian recruitment) community T2DM and vascular risk screening programme in the UK. By assessing feasibility and efficacy of T2DM screening, it will inform national disease prevention policy and contribute significantly to our understanding of the health care needs of UK South Asians.

Trial registration

Clinicaltrial.gov (NCT00318032).     

Pest pressure,hurricanes, and genotype interact to strongly impact stem form in young loblolly pine (Pinus taeda L.) along the coastal plain of North Carolina

Key message

Stem defects in loblolly pine due to insect pests and wind damage can decrease economic value and affect ecosystem function, however silvicultural management can decrease the impact of these stresses.

Abstract

Loblolly pine (Pinus taeda L.) is one of the most important tree crops in the southern United States, comprising 45 % of commercial forestry land. Stem defects can reduce timber product quality and influence competitive interactions. We examined the effects of controlling Nantucket pine tip moth (Rhyacionia frustrata Scudder in Comstock, 1880) and site management (fertilizer or herbicide use) on stem defects, of two full-sib families (C1 and C2) and two clonal varieties (V1 and V2) of loblolly pine at upper and lower coastal plain sites in North Carolina (UCP and LCP, respectively). At UCP, V1 and V2 had fewer stem defects with insecticide treatment indicating that pest pressure affected stem form. C2 had twice as many defects as other genotypes at LCP, while C1 had the most defects at UCP, showing that carefully matching site and genotype could improve plantation performance without increasing costs. Additionally, we examined the effects of Hurricane Irene on stem leaning at LCP. V1, the tallest genotype, was most strongly affected, indicating genotype differences in tolerance to this form of abiotic stress. Interestingly, insecticide treatment decreased the negative effects of the hurricane on C1 stem lean, indicating that tip moth pressure may make C1 more susceptible. Our results illustrate that the interaction of biotic and abiotic stressors, such as pest infestation and climate, can strongly impact stem form, potentially affecting ecophysiological function and economic value. Cost-effective silvicultural options, such as pest control and management of genetic resources can potentially decrease exposure to such environmental risk.     

Plasma IP-10, apoptotic and angiogenic factors associated with fatal cerebral malaria in India

Background

Knowledge on insecticide resistance in target species is a basic requirement to guide insecticide use in malaria control programmes. Malaria transmission in the Mekong region is mainly concentrated in forested areas along the country borders, so that decisions on insecticide use should ideally be made at regional level. Consequently, cross-country monitoring of insecticide resistance is indispensable to acquire comparable baseline data on insecticide resistance.

Methods

A network for the monitoring of insecticide resistance, MALVECASIA, was set up in the Mekong region in order to assess the insecticide resistance status of the major malaria vectors in Cambodia, Laos, Thailand, and Vietnam. From 2003 till 2005, bioassays were performed on adult mosquitoes using the standard WHO susceptibility test with diagnostic concentrations of permethrin 0.75% and DDT 4%. Additional tests were done with pyrethroid insecticides applied by the different national malaria control programmes.

Results

Anopheles dirus s.s., the main vector in forested malaria foci, was susceptible to permethrin. However, in central Vietnam, it showed possible resistance to type II pyrethroids. In the Mekong delta, Anopheles epiroticus was highly resistant to all pyrethroid insecticides tested. It was susceptible to DDT, except near Ho Chi Minh City where it showed possible DDT resistance. In Vietnam, pyrethroid susceptible and tolerant Anopheles minimus s.l. populations were found, whereas An. minimus s.l. from Cambodia, Laos and Thailand were susceptible. Only two An. minimus s.l. populations showed DDT tolerance. Anopheles vagus was found resistant to DDT and to several pyrethroids in Vietnam and Cambodia.

Conclusion

This is the first large scale, cross-country survey of insecticide resistance in Anopheles species in the Mekong Region. A unique baseline data on insecticide resistance for the Mekong region is now available, which enables the follow-up of trends in susceptibility status in the region and which will serve as the basis for further resistance management. Large differences in insecticide resistance status were observed among species and countries. In Vietnam, insecticide resistance was mainly observed in low or transmission-free areas, hence an immediate change of malaria vector control strategy is not required. Though, resistance management is important because the risk of migration of mosquitoes carrying resistance genes from non-endemic to endemic areas. Moreover, trends in resistance status should be carefully monitored and the impact of existing vector control tools on resistant populations should be assessed.     

Participation of African social scientists in malaria control: identifying enabling and constraining factors

Background

Insecticide-treated nets represent currently a key malaria control strategy, but low insecticide re-treatment rates remain problematic. Olyset? nets are currently one of two long-lasting insecticidal nets recommended by WHO. An assessment was carried out of the effect of Olyset? nets after seven years of use in rural Tanzania.

Methods

A survey of Olyset? nets was conducted in two Tanzanian villages to examine their insecticide dosage, bioassay efficacy and desirability compared with ordinary polyester nets.

Results

Of 103 randomly selected nets distributed in 1994 to 1995, 100 could be traced. Most nets were in a condition likely to offer protection against mosquito biting. Villagers appreciated mainly the durability of Olyset? nets and insecticide persistence. People disliked the small size of these nets and the light blue colour and preferred a smaller mesh size, features that can easily be modified. At equal price, 51% said they would prefer to buy an Olyset? net and 49% opted for an ordinary polyester net. The average permethrin content was 33%-41% of the initial insecticide dose of 20,000 mg/Kg. Bioassay results indicated high knock-down rates at 60 minutes, but the mosquito mortality after 24 hours was rather low (mean: 34%). No significant correlation was found between bioassay results and insecticide concentration in and on the net.

Conclusions

Olyset? nets are popular, durable and with a much longer insecticide persistence than ordinary polyester nets. Hence, Olyset? nets are one of the best choices for ITN programmes in rural malaria-endemic areas.     

Smoking among morbidly obese patients

Background

Urinary incontinence (UI) is a distressing problem for older people. To investigate the relationship between UI and respiratory symptoms among middle-aged and older men, a community-based study was conducted in Japan.

Methods

A convenience sample of 668 community-dwelling men aged 40 years or above was recruited from middle and southern Japan. The International Consultation on Incontinence Questionnaire-Short Form, the Medical Research Council's dyspnoea scale and the Australian Lung Foundation's Feeling Short of Breath scale, were administered by face-to-face interviews to ascertain their UI status and respiratory symptoms.

Results

The overall prevalence of UI was 7.6%, with urge-type leakage (59%) being most common among the 51 incontinent men. The presence of respiratory symptoms was significantly higher among incontinent men than those without the condition, especially for breathlessness (45% versus 30%, p = 0.025). The odds of UI for breathlessness was 2.11 (95% confidence interval 1.10-4.06) after accounting for age, body mass index, smoking and alcohol drinking status of each individual.

Conclusions

The findings suggested a significant association between UI and breathlessness in middle-aged and older men.     

The geographical distribution of lymphatic filariasis infection in Malawi

Background

Papua New Guinea is the only endemic country in the Western Pacific Region that has not yet introduced a countrywide programme to eliminate lymphatic filariasis. However, on Misima Island in Milne Bay Province, government and private sectors have collaborated to implement a pilot elimination programme. Although interim evaluation indicated that the programme has been parasitologically successful, an appreciation that sustainable health gains depend on understanding and accommodating local beliefs prompted this qualitative study.

Methods

We investigated Misima community members knowledge and attitudes about lymphatic filariasis and the elimination programme. A combination of focus groups and key informant interviews were used to explore participants perceptions of health; knowledge of the aetiology and symptoms of filariasis, elephantiasis and hydrocele; attitudes towards the disease and mass drug distribution; and the social structure and decision-making protocols within the villages.

Results

Focus group discussions proved inferior to key informant interviews for gathering rich data. Study participants did not consider lymphatic filariasis ("pom") a major health problem but were generally positive about mass drug administration campaigns. A variety of conditions were frequently and incorrectly attributed to filariasis. Participants expressed the belief that individuals infected with filariasis always had visible manifestations of disease. A common misconception was that taking drugs during campaigns provided long-term immunity against disease. The role of mosquito vectors in transmission was not generally appreciated and certain clinical presentations, particularly hydrocele, were associated with supernatural forces. Multiple adverse events were associated with mass drug administration campaigns and most study participants mentioned community members who did not participate in campaigns.

Conclusion

Important issues requiring educational intervention and elimination activity modification in the Misima region were identified during this study. Research outcomes should assist Papua New Guinea in developing and implementing a national elimination strategy and inform discussions regarding the appropriateness of current elimination strategies.     

Modelling the cost-effectiveness of mass screening and treatment for reducing Plasmodium falciparum malaria burden

Background

Past experience and modelling suggest that, in most cases, mass treatment strategies are not likely to succeed in interrupting Plasmodium falciparum malaria transmission. However, this does not preclude their use to reduce disease burden. Mass screening and treatment (MSAT) is preferred to mass drug administration (MDA), as the latter involves massive over-use of drugs. This paper reports simulations of the incremental cost-effectiveness of well-conducted MSAT campaigns as a strategy for P. falciparum malaria disease-burden reduction in settings with varying receptivity (ability of the combined vector population in a setting to transmit disease) and access to case management.

Methods

MSAT incremental cost-effectiveness ratios (ICERs) were estimated in different sub-Saharan African settings using simulation models of the dynamics of malaria and a literature-based MSAT cost estimate. Imported infections were simulated at a rate of two per 1,000 population per annum. These estimates were compared to the ICERs of scaling up case management or insecticide-treated net (ITN) coverage in each baseline health system, in the absence of MSAT.

Results

MSAT averted most episodes, and resulted in the lowest ICERs, in settings with a moderate level of disease burden. At a low pre-intervention entomological inoculation rate (EIR) of two infectious bites per adult per annum (IBPAPA) MSAT was never more cost-effective than scaling up ITNs or case management coverage. However, at pre-intervention entomological inoculation rates (EIRs) of 20 and 50 IBPAPA and ITN coverage levels of 40 or 60%, respectively, the ICER of MSAT was similar to that of scaling up ITN coverage further.

Conclusions

In all the transmission settings considered, achieving a minimal level of ITN coverage is a “best buy”. At low transmission, MSAT probably is not worth considering. Instead, MSAT may be suitable at medium to high levels of transmission and at moderate ITN coverage. If undertaken as a burden-reducing intervention, MSAT should be continued indefinitely and should complement, not replace, case management and vector control interventions.     

Evaluation of next generation sequencing platforms for population targeted sequencing studies

Background

Next generation sequencing (NGS) platforms are currently being utilized for targeted sequencing of candidate genes or genomic intervals to perform sequence-based association studies. To evaluate these platforms for this application, we analyzed human sequence generated by the Roche 454, Illumina GA, and the ABI SOLiD technologies for the same 260 kb in four individuals.

Results

Local sequence characteristics contribute to systematic variability in sequence coverage (>100-fold difference in per-base coverage), resulting in patterns for each NGS technology that are highly correlated between samples. A comparison of the base calls to 88 kb of overlapping ABI 3730xL Sanger sequence generated for the same samples showed that the NGS platforms all have high sensitivity, identifying >95% of variant sites. At high coverage, depth base calling errors are systematic, resulting from local sequence contexts; as the coverage is lowered additional 'random sampling' errors in base calling occur.

Conclusions

Our study provides important insights into systematic biases and data variability that need to be considered when utilizing NGS platforms for population targeted sequencing studies.     

Head and Neck Manifestations of Paracoccidioidomycosis: An Epidemiological Study of 36 Cases in Brazil

Background

Paracoccidioidomycosis is a systemic mycosis caused by the dimorphic fungus Paracoccidioides brasiliensis. It is the principal systemic mycosis in Brazil, with higher incidence rates in the southern, southeastern, and midwestern regions. It primarily involves the lungs, but head and neck manifestations are common, and differential diagnosis with granulomatous and neoplastic diseases should therefore be considered.

Methods

We conducted a retrospective analysis of medical records of paracoccidioidomycosis cases with head and neck manifestations in southern Brazil over a 10-year period, from 1998 to 2008.

Results

A total of 36 cases of paracoccidioidomycosis were confirmed by histopathological examination, fungal investigation, or culture. Most cases consisted of men with smoking and/or chronic drinking habits and with poor hygiene and nutrition.

Conclusions

Paracoccidioidomycosis is endemic to southern Brazil. Most cases with mucocutaneous manifestations affect the head and neck region. Given that risk factors and clinical manifestations are similar to those of head and neck carcinomas, a differential diagnosis has to be done.     

Cerebrospinal fluid and serum biomarkers of cerebral malaria mortality in Ghanaian children

Background

Successful malaria vector control depends on understanding behavioural interactions between mosquitoes and humans, which are highly setting-specific and may have characteristic features in urban environments. Here mosquito biting patterns in Dar es Salaam, Tanzania are examined and the protection against exposure to malaria transmission that is afforded to residents by using an insecticide-treated net (ITN) is estimated.

Methods

Mosquito biting activity over the course of the night was estimated by human landing catch in 216 houses and 1,064 residents were interviewed to determine usage of protection measures and the proportion of each hour of the night spent sleeping indoors, awake indoors, and outdoors.

Results

Hourly variations in biting activity by members of the Anopheles gambiae complex were consistent with classical reports but the proportion of these vectors caught outdoors in Dar es Salaam was almost double that of rural Tanzania. Overall, ITNs confer less protection against exophagic vectors in Dar es Salaam than in rural southern Tanzania (59% versus 70%). More alarmingly, a biting activity maximum that precedes 10 pm and much lower levels of ITN protection against exposure (38%) were observed for Anopheles arabiensis, a vector of modest importance locally, but which predominates transmission in large parts of Africa.

Conclusion

In a situation of changing mosquito and human behaviour, ITNs may confer lower, but still useful, levels of personal protection which can be complemented by communal transmission suppression at high coverage. Mosquito-proofing houses appeared to be the intervention of choice amongst residents and further options for preventing outdoor transmission include larviciding and environmental management.     

Analysis of raw cork production in Portugal and Catalonia using life cycle assessment

Purpose

This study aims to (1) evaluate the environmental impacts associated with the three types of raw cork produced in Portuguese cork oak woodlands (in Alentejo region) considering two alternative practices for stand establishment (plantation and natural regeneration), (2) compare the environmental impacts of raw cork production in Portuguese cork oak woodlands and in Catalonian cork oak forests, and (3) assess the influence of different allocation criteria for partitioning the environmental impacts between the different types of raw cork produced.

Methods

A cradle-to-gate approach was adopted starting with stand establishment up to cork storage in a field yard. The system boundaries include all management operations undertaken during the following stages: stand establishment, stand tending, cork stripping, and field recovery. The allocation of the environmental impacts to reproduction, second, and virgin cork was based on mass and market price criteria. An alternative allocation approach was simulated by allocating environmental impacts also to the wood produced in the cork oak stands. The impact assessment was performed using the characterization factors recommended by the International Reference Life Cycle Data System (ILCD).

Results and discussion

In Portugal, cork produced from naturally regenerated stands has a better environmental performance than cork produced from planted stands, but the differences are smaller than 10 %. Different management models of cork oak stands in Portugal and Catalonia (agro-silvopastoral system and forest system, respectively) originate different impact levels, which tend to be significantly lower in Catalonia. The environmental hot spots in the two regions are also distinct. In Catalonia, they are associated with cleaning, road maintenance, and worker and cork transport. In Portugal, they are fertilization, pruning, and cleaning. The two allocation criteria affect significantly the results obtained for virgin cork in Portugal and for virgin and second cork in Catalonia. Besides, when impacts are also allocated to wood, mass allocation should be avoided as it would not create incentives for a sustainable management of cork oak stands.

Conclusions

The environmental impact from Catalonian cork may be reduced by decreasing mechanized shrub cleaning and road maintenance operations through the introduction of livestock in cork oak forests, and also by a better planning of management operations. For the Portuguese cork, improvements may be achieved by optimizing fertilizer dosage, planting nitrogen-fixing crops and pastures that improve soil quality, avoiding unnecessary operations, improving the efficiency of management operations, and increasing tree density.     

Use of local anaesthetics and adjuncts for spinal and epidural anaesthesia and analgesia at German and Austrian University Hospitals: an online survey to assess current standard practice

Background

The present anonymous multicenter online survey was conducted to evaluate the application of regional anaesthesia techniques as well as the used local anaesthetics and adjuncts at German and Austrian university hospitals.

Methods

39 university hospitals were requested to fill in an online questionnaire, to determine the kind of regional anaesthesia and preferred drugs in urology, obstetrics and gynaecology.

Results

33 hospitals responded. No regional anaesthesia is conducted in 47% of the minor gynaecological and 44% of the urological operations; plain bupivacaine 0.5% is used in 38% and 47% respectively. In transurethral resections of the prostate and bladder no regional anaesthesia is used in 3% of the responding hospitals, whereas plain bupivacaine 0.5% is used in more than 90%. Regional anaesthesia is only used in selected major gynaecological and urological operations. On the contrary to the smaller operations, the survey revealed a large variety of used drugs and mixtures. Almost 80% prefer plain bupivacaine or ropivacaine 0.5% in spinal anaesthesia in caesarean section. Similarly to the use of drugs in major urological and gynaecological operations a wide range of drugs and adjuncts is used in epidural anaesthesia in caesarean section and spontaneous delivery.

Conclusions

Our results indicate a certain agreement in short operations in spinal anaesthesia. By contrast, a large variety concerning the anaesthesiological approach in larger operations as well as in epidural analgesia in obstetrics could be revealed, the causes of which are assumed to be primarily rooted in particular departmental structures.     

Biological nitrification inhibition in sorghum: the role of sorgoleone production

Aims

Organically-certified orchard floor management was assessed for its ability to improve soil fertility and biological activity and apple orchard performance.

Methods

‘Ambrosia’/B9 apple was maintained for the first six growing seasons with four orchard floor treatments, including 1) annual compost application; 2) in-row application of mown alfalfa grown between the rows; 3) bark mulch plus in-row application of mown hay; and 4) black plastic mulch.

Results

Soil collected from 0 to 10 cm indicated high soil organic matter and exchangeable K were measurable for all treatments by the second year. After 6 years, highest organic matter, total-, particulate- and mineral–C were associated with soil beneath the bark mulch treatment which also had most vigorous trees, decreased leaf N and elevated leaf P and K. Addition of alfalfa and bark mulch were equally effective at maintaining high exchangeable K and soil phosphatase enzymes, high total and particulate-N by the fourth year.

Conclusions

Despite measurable improvements in soil properties among treatments, fruit yield and quality were minimally affected by management implying no limitations to adoption of any of the assessed strategies.