Factors affecting sporulation and infection of Peronospora sparsa in New Zealand boysenberry gardens

Downy mildew, caused by Peronospora sparsa, is an economically important disease of boysenberries. Sporangia produced on infected tissue initiate berry infections; however the timing of sporangial release under New Zealand environmental conditions is unknown. The number of P. sparsa sporangia trapped on Vaseline®-coated slides placed weekly in three boysenberry gardens in the Nelson region from October to December in 2010 and September to December in 2011 was determined. Climate data were used to determine environmental factors that promoted sporangia production/release. Incidence of dryberry symptoms and sporulation on tissue samples incubated at 15 or 20°C under high relative humidity (RH) were assessed. Peronospora sparsa sporangia were observed on slides from all three sites, with peak sporangial numbers in mid-November in both years. Sites with the highest numbers of sporangia trapped in November had higher dryberry incidence in December. Data indicated that sporangial release was triggered by percentage of rainy days, RH and warm temperatures (16-23°C) in early spring, where high moisture periods promoted sporulation and a subsequent dry period allowed sporangial release. This study improves understanding of the timing of sporangial release to inform management practices

A one step nested PCR method for detection of Peronospora sparsa, the downy mildew pathogen, in boysenberry (Rubus ursinus)

Downy mildew is a major disease of boysenberries in New Zealand, caused by Peronospora sparsa. Most boysenberry plant material, including tissue culture propagated plants are systemically infected and this pathogen also presents as a latent infection. The current nested PCR method to detect latent infection of P. sparsa in asymptomatic boysenberry plants is time consuming as it employs two separate PCR, with potential contamination producing false positive and/or false negative results. To overcome these issues a one step nested PCR method was developed. The method was optimised for primer concentrations, PCR cycle number and DNA concentration. DNA was extracted using a CTAB method. The one step nested PCR method could detect latent infection of P. sparsa in both dormant and active plant growth at 0.4 pg genomic DNA. The most reliable detection was achieved from crown or root tissues. For surety of the infection status, replicate plant tissues should be assessed by PCR as inconsistency between the one step nested PCR and fluorescence microscopy indicated that P. sparsa colonisation is discontinuous through the plant. This method can be recommended for screening P. sparsa latent infection in boysenberry mother plants and daughter plants in nurseries, due to high sensitivity, improved throughput, low cost, and low contamination risk

Economic evaluation of an Australian nurse home visiting programme: a randomised trial at 3 years

ObjectivesTo investigate the additional programme cost and cost-effectiveness of &lsquo;right@home&rsquo; Nurse Home Visiting (NHV) programme in relation to improving maternal and child outcomes at child age 3 years compared with usual care.DesignA cost&ndash;utility analysis from a government-as-payer perspective alongside a randomised trial of NHV over 3-year period. Costs and quality-adjusted life-years (QALYs) were discounted at 5%. Analysis used an intention-to-treat approach with multiple imputation.SettingThe right@home was implemented from 2013 in Victoria and Tasmania states of Australia, as a primary care service for pregnant women, delivered until child age 2 years.Participants722 pregnant Australian women experiencing adversity received NHV (n=363) or usual care (clinic visits) (n=359).Primary and secondary outcome measuresFirst, a cost&ndash;consequences analysis to compare the additional costs of NHV over usual care, accounting for any reduced costs of service use, and impacts on all maternal and child outcomes assessed at 3 years. Second, cost&ndash;utility analysis from a government-as-payer perspective compared additional costs to maternal QALYs to express cost-effectiveness in terms of additional cost per additional QALY gained.ResultsWhen compared with usual care at child age 3 years, the right@home intervention cost $A7685 extra per woman (95$A7006 to $A8364) and generated 0.01 more QALYs (95$A50&thinsp;000 per QALY.ConclusionsBenefits of NHV to parenting at 2 years and maternal health and well-being at 3 years translate into marginal maternal QALY gains. Like previous cost-effectiveness results for NHV programmes, right@home is not cost-effective at 3 years. Given the relatively high up-front costs of NHV, long-term follow-up is needed to assess the accrual of health and economic benefits over time.Trial registration numberISRCTN89962120.</jats:sec