Development of national strategies to manage citrus gall wasp (CT15006)
Status: Ongoing project
What’s it all about? Citrus gall wasp is a major and widespread pest in citrus. Established in 2015, this project is developing national management strategies for the wasp based on:
- Enhanced biological control
- Better timing of control actions, through investigation of the relationship between weather and the wasp’s development (the development of ‘degree-day’/phenology models)
- Improved use of oil and other potential repellents
- Identification of new insecticide options compatible with integrated pest management approaches.
What’s the latest update? Some of the project’s initial activity focused on the efficacy of petroleum spray oil in deterring citrus gall wasps from laying eggs. This work used BioPest® paraffinic mineral oil and lemon shoots as the host material. It found that at a one per cent rate the oil was successful in preventing egg-lay in all test shoots, but that at an 0.5 per cent rate the oil may not be sufficient in the control of citrus gall wasp (a finding supported by anecdotal evidence from some growers).
Other work has included:
- Field trials to confirm the effectiveness of Surround® in deterring egg-lay, and to confirm the effectiveness of Samurai® and Confidor® Guard in controlling citrus gall wasp larvae
- Estimating the effect of heat stress on the survival of citrus gall wasp parasitoids
- Ongoing collection of citrus gall wasp phenology data.
For the 2016-17 period of the project, activities will include:
- Investigating the scope for reducing Surround® rate
- Mass rearing of citrus gall wasp parasitoids
- Collection of toxicity data of Samurai® on key beneficial insects in citrus
- Autumn application of Samurai® and Confidor Guard® in Valencia blocks
- Effects of hedging timing on citrus gall wasp control and yield
- Development of a citrus gall wasp infestation map
- Scoping studies of factors affecting the selection of egg-lay sites and orientation by citrus gall wasp
- Releases of parasitoid wasps.
Development of phenology models and a timing guide for the management of Californian red scale in Australian citrus (CT15008)
Status: Ongoing project
What’s it all about? Aphytis wasps and petroleum spray oils are used in the control of Californian red scale (CRS) in Australian citrus crops – but they are only (or mostly) effective at certain life stages of the pest, and thus timing is everything.
This project is developing degree-day-based phenology models to predict the timing of peak abundance of vulnerable life stages of CRS to better guide Aphytis releases and oil applications.
What’s the latest update? This project is still in the early stages of data collection. During the 2015-16 season, seasonal patterns of CRS male flights were monitored, with pheromone traps placed at three sites in the Riverina area and two sites in Sunraysia.
This first-year data showed multiple peaks of male flight over a season. The first two post-winter peaks occurred around similar dates across the different sites.
Together with crawler data, timing of the two male flight peaks can be used to predict when crawlers are likely to become abundant, and hence when to spray to achieve a better control of CRS populations.
A pheromone trap used to monitor CRS male flight
Australian Citrus Quality Standards – stage 3 (CT15013)
Status: Ongoing project
What’s it all about? Established in 2011 and beginning its third stage this year, the Australian Citrus Quality Standards program has an overarching goal of ensuring the price of Australian citrus is maximised. To do this, it is working to solidifying the industry’s reputation as a reliable supplier of high-quality citrus, capitalising on aspects of taste, colour, freshness and food safety.
Some of the key objectives of the project include:
- Capturing and disseminating maturity levels of fruit for sale in the wholesale market to inform marketing decisions
- Developing and implementing procedures to improve quality outcomes, including a maximum granulation standard for Imperial mandarins to help restore consumer confidence
- Increasing knowledge in the supply chain to achieve greater adoption of quality improvement practices
- Developing a standard operating procedure for start of harvest that reduces the likelihood of immature fruit entering the supply chain.
What’s the latest update?
- Back in April quality testing of citrus in market commenced, with reporting including an Imperial mandarin granulation assessment for the first time. Nearly 550 tests had been conducted at the time of reporting to Hort Innovation, with 14 Australian Citrus Quality Standards reports delivered to value-chain participants.
- A proposed maximum granulation standard has been developed and endorsed by the Citrus Australia board. This standard is now being extended to the citrus industry through Australian Citrus News and presentations at meetings. Quality standards materials are also being developed for quality-control personnel across the value chain.
- A citrus maturity calculator app for iPhone and Android devices has continued to be updated and maintained.
- The Manager of Citrus Quality and Information (MCQI) has continued to liaise with the entire supply chain on Australian Citrus Quality Standards, including visiting packing sheds, participating in regular teleconferences with packers, and meeting with quality assurance teams at the large retailers.
- A pilot standard operating procedure for harvest protocol has been raised with retailers and a draft is being prepared – it is intended that the procedure will be in place for the 2017 season.
- A pilot program of pre-season testing and reporting was conducted earlier in 2016, with learnings to be applied for the 2017 season and results to be extended to industry.
- Citrus Quality Community of Practice and Domestic Market Leadership Groups have been established and at least one meeting of each held.
Increasing market access, profitability and sustainability through integrated approaches to fungal disease control (CT13020)
Status: Near-completed project
What’s it all about? Established in 2013, this project aims to overcome trade barriers by looking at fungal disease control in the citrus industry. It has a specific focus on citrus black spot (CBS) and emperor brown spot (EBS), and includes the investigation of:
- Fungal disease control protocols
- Improved fungicide options
- The use of disease-resistant varieties to reduce the use of fungicides.
What’s the latest update? This project is currently wrapping up, with a final report due in early 2017 and no new milestone report due in the period since the last edition of Hortlink (Winter 2016). At the time of last reporting, a treatment schedule had commenced for the project’s EBS trial, which was to include a treatment specifically for residue removal at commercial maturity.
Citrus industry communications (CT15009)
Status: Ongoing project
What’s it all about? This project delivers effective and timely communications to ensure Australian citrus growers and other industry stakeholders are kept up-to-date with the latest R&D and marketing activities, and other industry news and information. Among its key goals are to support decision-making within citrus businesses and to facilitate the uptake of new research and technologies, to ultimately strengthen the profitability and sustainability of the industry.
This project is supported by the project Citrus Australia Limited – communication support on CT15009 (CT15015).
What’s the latest update? A number of regular communication channels continue to be produced and maintained by this project, including but not limited to:
- The quarterly national magazine, Australian Citrus News, which has been redesigned under this project
- Monthly Season Update newsletters, also recently redesigned
- Fortnightly Citrus eNews e-newsletters
- The industry website, www.citrusaustralia.com.au.
The project also produces industry media releases as required, maintains a photography database, and develops grower case studies for peer-to-peer learning.
The spring edition of Australian Citrus News
Other R&D projects of note…
» Protecting Australian citrus germplasm through improved diagnostic tools project (CT14009). Running since 2014, this project is assessing, developing and validating diagnostic methods for a number of endemic graft-transmissible pathogens of citrus to help secure the high health status of the Australian citrus industry. The project also aims to boost Australia’s preparedness for an incursion of devastating citrus disease Huanglongbing.
» Australian citrus industry innovation and market development program (CT15012), which begun at the start of 2016 and has three broad focus areas for the citrus industry: market development, market information and market access.
» Evaluating new citrus varieties 2013-17 (CT12026), for which the number of varieties being evaluated continues to grow. Field evaluation of new material will begin in 2017/18, when the first fruit is produced from top-worked trees.
» Evaluation and commercialisation of new citrus rootstocks (CT13042), which has been running since 2014 to make promising new rootstocks commercially available.
» Agrichemical residue monitoring program for Australian citrus exports – stage 2 (CT15016), which commenced in recent months.
» MRL risk analyses and risk management options for major citrus export markets (CT14003), which collects, prepares and supplies maximum residue level (MRL) information to keep the Australian citrus industry informed of changes that could lead to pesticide-related market problems for exporters.