The project was officially launched in Bhutan in June 2007. At this inception meeting the project objectives and main activities for the 2007 season were outlined. A draft survey of grower practices was circulated and feedback incorporated. The main activities for 2007/08 were the selection of demonstration orchards, collection of leaf & soil samples from the demonstration orchards for nutrient analysis, a comprehensive survey of citrus grower practices from all regions of Bhutan, to start monitoring the citrus phenological stages in different growing regions of Bhutan and to begin to implement best management practices on the demonstration orchards.

Four demonstration orchards have been established. Basic improvements such as basin formation to allow for application of water and inorganic fertilisers and the clearing of vegetation under trees were the first activities undertaken. Soil & leaf samples were collected and analysed and a basic fertiliser program started in February 2008. Selected trees at each of the sites have been pruned to varying degrees to assess the timing of operations and tree response in Bhutan (February & April 2008). Tensiometers were installed at one site at Rimchu in April 2008 to help in assessing soil moisture levels and water application timing. Meteorological and other general site information from the Punakha and Phuntsholing regions have been sourced. Citrus phenological data is also being recorded at these sites. More extensive soil sampling was undertaken in early 2008 and the results have just been received. More leaf samples will be taken in August-September 2008. A nutrient survey of citrus orchards in Bhutan will be undertaken in 2008 through the collection of about 100 leaf samples from the different growing regions. In late 2008 an application of gibberellic acid (GA) will be made to selected trees (when fruit are almost fully coloured) to delay fruit maturity (harvest) and improve rind firmness. The work on GA will be linked to researchers from the National Post Harvest Centre for assessment and measurement of fruit quality & firmness.

The first two week training visit to Australia by three Bhutanese personnel was made in October-November 2007. During the visit a wide range of both formal and informal training activities were undertaken. Formal training workshops were provided on soil and irrigation management (accredited course), citrus nutrition & citrus canopy management -including topworking. Practical sessions were undertaken on pruning, budding, grafting & topworking of citrus. Visits to two commercial citrus nurseries provided an insight into nursery production practices in Australia. Visits were made to a commercial citrus packing company and juicing plant to look at post harvest operations and facilities. Visits to the Auscitrus (supplier of citrus rootstock seed and budwood to the Australian industry) facilities at EMAI, Camden and the new established facility at Dareton were undertaken to provide an insight into the facilities and operations used to maintain the Australian repository of clean citrus germplasm. A visit to a commercial citrus orchard demonstrated Australian production practices.

The citrus grower survey was distributed to extension officers throughout Bhutan who collected information from citrus growers in the main production districts throughout July-December 2007. The survey focussed on collecting data on tree plantings, replanting plans, pest and disease problems (with an emphasis on Chinese citrus fruit fly & the pysllid vector of Huanglongbing), current control strategies, fertiliser and water application programs. A total of 401 surveys were completed which far exceeded expectations. All the survey data was entered into a master record sheet by project officer Phuntsho and sent to Australia in February 2008. Preliminary analysis of the survey data was undertaken at Gosford by Biometrician Anne Harris with additional input provided by the Australian project officer Julian Connellan. The data is currently being compiled into a comprehensive report outlining results on both a country and district basis. More detailed analysis may be warranted for some survey questions. Assumptions about the data collected will also need to be checked by the local DoA (Department of Agriculture) staff in the various growing regions before the final report is released. The survey data will provide an invaluable source of baseline data for this project and will be useful for any other projects undertaken on citrus in Bhutan.

Several training workshops have been undertaken in Bhutan by both the Bhutanese and Australian project team for extension and research personnel and these are outlined in Section 4.

NSW DPI has produced a training video for citrus growers in Australia & Bhutan on "Topworking Citrus" demonstrating the main budding and grafting techniques used in propagating citrus trees.

All promising genetic rootstock material from previous NSW DPI rootstock breeding programs undertaken at the NSW DPI Gosford site has been collected and transferred to the citrus arboretum at NSW DPI Dareton Agricultural Research and Advisory station.

The project was launched in Bhutan in 2007 and is now in its second year and continues to progress towards the aim of increasing sustainable yield of quality mandarins through the implementation of on farm best management practices. The major activities which took place over the 2008/09 year were:

The implementation of improved management practices on demonstration orchards.
The monitoring and documentation of citrus phenological stages in various citrus growing regions of Bhutan.
A visit to Australia by a contingent of four Bhutanese personnel for training.
The delivery of formal training to 82 research and extension staff in Bhutan by both the Australian and Bhutanese project team in August & October 2008 and May 2009.
The initiation of a survey of citrus tree nutritional status across Bhutan, collection and analysis of 40 leaf samples.
The delivery of the final report of the survey of citrus grower practices from the major citrus growing regions of Bhutan.
The development and delivery of eight training packages in the form of Power Point presentations for use by Australian and Bhutanese staff.
The delivery of a mandarin production guide in draft form for comment by Bhutanese research and extension personnel.
Pest and Disease survey of Bhutan orchards in the Rimchu, Punakha, and Tsirang districts.
Establishment of the Bhutan Citrus Coordination Committee comprised to plan and implement activities for the national citrus industry.
Collection of citrus disease samples and pysllid samples for species identification and Huanglongbing testing in Australia.

Improved management practices have been implemented at all four demonstration orchards with responses to pruning, the addition of chemical fertilisers and pest control measures assessed over the last 12 months. Initial response by citrus trees to various levels of pruning has been very positive with the full effects to become apparent over the next twelve months. Gibberellic acid which is used to delay mandarin rind ageing to prolong the harvest season and help the fruit better withstand post harvest handling practices has been trialled at two of the demonstration orchards. Initial results have been positive with formal research trials to be undertaken by the National Post-Harvest Centre (NPHC) during the 2009 season. The installation of tensiometers at the Rimchu demonstration orchard has provided valuable soil moisture data which has been used to further refine the management practices put in place at the site. Meteorological data was sourced from Punakha and Phuntsholing and used in a NSW Department of Primary Industries (DPI) Heat Unit Mapping model which is run by Dr Tahir Khurshid (Research Horticulturist, NSW DPI) to compare the citrus growing regions of Australia to those in Bhutan, to give Australian and Bhutanese personnel a clearer understanding of the climatic regions in both countries in which citrus is grown. This information has been presented in Australia and in Bhutan to research and extension personnel.

A survey of 401 citrus farmers from across Bhutan was conducted in 2007. The survey results were statistically analysed and a comprehensive report developed outlining results on a national, district and farm size basis, looking at issues such as tree age, replant plans, pest and disease and current control strategies and fertiliser and water application programs. The report was formally handed to the Honourable Secretary Ministry of Agriculture, Sherub Gyaltshen by the Australian project officer Julian Connellan and the Bhutanese project leader Citrus Dorjee in October 2008. Copies of the report were also formally handed to the Director of the Department of Agriculture Chencho Norbu and the Joint Director Ganesh B.Chettri. The findings of the survey were presented at a workshop in Bhur (Sapang district) to 28 research and extension personnel. The report has since been distributed to all relevant Bhutanese staff. Information from the survey is being used to plan activities for the Bhutan citrus industry now and in the future.

A national survey of the nutritional status of citrus orchards in Bhutan was initiated on the April 2008 visit, to gain a better understanding of the impact of current fertiliser programs used by Bhutanese farmers on the nutritional status of their trees. Over 40 samples from various citrus growing regions across Bhutan have been taken and analysed. Further sampling will take place over the next twelve months to continue to develop a profile of the nutritional status of citrus in Bhutan and will culminate with the development of a report detailing findings and recommendations. Additionally two duplicate leaf samples from Australia were delivered to the National Soil Service Centre (NSSC) in Bhutan in May 2009 to compare results between Australian and Bhutan laboratories.

A five day pest and disease survey of citrus orchards was undertaken in May 2009 with scientists from the Bhutan Department of Agriculture and National Plant Protection Centre and visiting citrus entomologists and pathologists from Australia. Orchards in the Punakha and Tsirang district were visited and disease and pysllid samples were collected for further identification and analysis in Bhutan and Australia. The survey provided an invaluable insight into the occurrence and distribution of Huanglongbing (HLB) and the pysllids Diaphorina citrii and Diaphorina communis and their relationship with altitude. Additionally it confirmed the importance of powdery mildew as a major cause of citrus tree dieback and death. A control strategy for this disease needs to be urgently developed and implemented. It is suspected that a significant percentage of cases of orchard decline/tree death has been wrongly attributed to HLB, whereas it is more likely that the cause has been as a result of powdery mildew infection. The information derived from this survey will ideally result in the production of collaborative scientific publications for Bhutanese and Australian scientists.

A package of 8 Power Point based training packages were developed and distributed for use by Australian and Bhutanese research and extension personnel. The presentations cover the following areas:
citrus canopy management
citrus establishment
citrus nutrition
citrus phenology
leaf analysis and sampling
soil analysis
general overview of soils
outline of the Australian citrus industry.

A mandarin production guide for use by Bhutanese extension officers and farmers has been developed and distributed to Bhutanese extension and research officers for comment. Feedback has been received and the final management guide will be available for distribution in July 2009. The guide will be a reference document for Bhutanese extension staff and citrus growers covering the key management practices recommended for citrus, including control measures for major pests and diseases, fertiliser and water requirements. Practices are linked to crop phenological stages so that it is relevant to all citrus growing regions.

In July 2008 a contingent of four Bhutanese Department of Agriculture (DoA) personnel (comprising one soil research officer, one post harvest research officer, one research assistant and the Bhutan project leader) visited Australia for two weeks of formal and informal training. Formal training included soil and irrigation management (accredited course), on-farm food safety and quality assurance, post harvest handling of citrus, citrus nutrition and canopy management. Practical sessions included training in laboratory pathology methods (Post harvest research officer), mandarin harvesting, grading of mandarins, fruit quality testing and how to use gibberellic acid.

Visits included inspection of the NSW DPI Fruit fly disinfestation research facilities at Gosford, an inspection of a citrus packing shed in the Gosford region and a citrus juice plant and packing facility in Mildura to look at post harvest operations and facilities. A visit to the Auscitrus (citrus rootstock and budwood scheme) facility at Dareton was undertaken to look at nursery practices such as rootstock seed collection and the processing and sowing of seed. This was followed by training in citrus budding and field grafting at NSW DPI Dareton. CITTgroup (Citrus Information Technology Transfer Groups) meetings and field walks were attended in Griffith and in Mildura to hear about issues faced by Australian citrus growers and new varieties now available to the citrus industry. These meetings allowed the Bhutanese to interact with Australian growers and gain an insight into the operation of industry facilitated citrus extension field days and seminars.

In August 2008 two 2 day training workshops were run in the Samdrupjongkhar and Pemagatshel districts for 22 extension officers by project staff in Bhutan. Training was provided on canopy management, soil nutrition, crop phenology, leaf sampling, reworking and crop sanitation practices.

In October 2008 a delegation from the Australian ACIAR project team travelled to Bhutan to assess the impacts of improved management practices at the demonstration orchards at Rimchu and to hold a three day training workshop for 28 Bhutanese research and extension personnel. Further details of this training are outlined in Section 4.

In October 2008 three project personnel (Graeme Sanderson, NSW DPI, Dorjee and Ms. Pema Yuden, MoA Bhutan) attended the 11th International Citrus Congress in China. The congress provided opportunities for the Bhutanese personnel to meet and initiate linkages with international citrus researchers and to get an overview of international citrus research activities.

In January 2009 a field day for local growers on canopy management was held at the Rimchu demonstration orchard by Bhutan project staff.

In May 2009 a delegation from the Australian ACIAR project team accompanied two Australian scientists working on Huanlongbing to Bhutan to undertake a pest and disease survey of citrus orchards, discuss control and management options for Huanglongbing (HLB) and conduct training on pest and disease management. Formal training was conducted for 28 personnel from the National Plant Protection Centre (NPPC), Bhutan Agriculture & Food Regulatory Authority) BAFRA and research staff on germplasm management, nursery production practices, citrus pests and diseases, with an emphasis on Huanlongbing, it's insect vector and powdery mildew. Further details of this training are outlined in Section 4.

In 2008 project leader Dorjee set up a Citrus Coordination Committee to discuss and plan research and extension activities for the citrus industry in Bhutan. Four meetings were held in Thimphu in June, July, September and January with attendance of around 10 key research & extension project collaborators. Additionally two stakeholder meetings were held with the Australian team during the October 2008 visit to Bhutan.

The project was launched in Bhutan in 2007 and is now in its third year and continues to progress towards the aim of increasing sustainable yield of quality mandarins through the implementation of on-farm best management practices. The major activities which took place over the 2009/10 year were:
The continued implementation of improved management practices on project demonstration orchards.
The establishment of an additional 3 regional demonstration sites (using funding from the ASSP project) in the districts of Tsirang Dagana and Sarpang to showcase management practices.
The continued monitoring and documentation of citrus phenological stages in various citrus growing regions of Bhutan.
The establishment of a permanent on-site irrigation system at a Rimchu demonstration orchard using novel pumping technology imported from Australia.
Trials to assess the effects of gibberellic acid (GA) on mandarin rind quality and fruit maturity were undertaken in 2009 and will continue in the 2010 season. One positive but unexpected result was that treated fruit did not develop post harvest moulds as opposed to untreated fruit.
The development and implementation of trials to determine the effectiveness of wettable sulphur for powdery mildew control in citrus in Bhutan.
Supply and testing of horticultural mineral oils (HMO) for any phytotoxicity effects on mandarins in high altitudes.
A visit to Australia in September 2009 by a contingent of seven Bhutanese personnel for training.
A visit to Australia in October 2009 by the Bhutanese ACIAR project officer Mr Phuntsho Wangdi to undertake formal training activities in citrus production practices for a one month period.
The delivery of a formal training course on irrigation and soil management for 25 extension and research officers in Bhutan by the Australian project team in May 2010.
Completion of statistical analysis and production of a report on a citrus nursery survey (based on 56 private nurseries) undertaken by Bhutanese project staff in 2008/09 in 6 districts of Bhutan.
Completion and posting on the Ministry of Agriculture Bhutan website of the 'Production Guide for Mandarin Orchards in Bhutan'.
Leaf samples collected in Bhutan during the May 2009 pest and disease survey of citrus orchards and nurseries were tested in Australia and Bhutan by conventional and real-time PCR for the presence of Huanglongbing (HLB) to validate the results in both laboratories and investigate the effect of altitude on disease incidence.
The powdery mildew occurring in Bhutan has now been identified as Odium citri - this is the first report of this species in Bhutan. A Scientific paper authored by Holford P, Donovan NJ, Thinlay, Kabanoff E, Wildman O, Hardy S, Beattie GAC, Namgay Om, Dorjee, Phuntsho Wangdi titled 'First report of Odium citri in Bhutan' has been accepted for publication in Australasian Plant Diseases Notes.
Testing of psyllids collected from HLB infected trees during the May 2009 trip to determine if they are infected with HLB is in progress. The leaf and psyllid samples from Bhutan are also being used in Australia to update and validate procedures in the national diagnostic standard for HLB.
Improved management practices continue to be implemented at all four project demonstration sites with the continued application of chemical fertilisers and the application of pest control measures and canopy management practices. Soil moisture monitoring equipment (tensiometers) installed at the Rimchu demonstration site has continued to provide valuable soil moisture data throughout the growing season.
Data obtained from tensiometers has shown that soil moisture levels during the winter (dry) season are usually critically low. A drip irrigation system has been installed at the Rimchu demonstration site to show the benefits of irrigating citrus during dry periods. A novel pump has also been installed to provide the water for the irrigation system. The pump does not require fuel or electricity to operate. However it has to be removed from the river during the wet season due to the ferocity of the water flow.
A survey of 56 private citrus nurseries from 6 of the 17 major citrus growing districts of Bhutan was conducted in 2008. The survey results were statistically analysed and a comprehensive report produced describing nursery size, pest and disease control strategies and fertiliser and water application programs. The report was provided to the Project Leader Bhutan in May 2010.
In September 2009 a contingent of seven Bhutanese Department of Agriculture (DoA) personnel (comprising 3 research officers, two extension officers and one engineer) visited Australia for two weeks of formal and informal training. Formal training included soil and irrigation management (accredited course), practical training in citrus shoot tip grafting, PCR analysis and plant diagnostics.
During the trip two members of the group were stationed with Nerida Donovan (Citrus Plant Pathologist) at Elizabeth Macarthur Agricultural Institute (EMAI) for specialised training in plant diagnostics and to attend the Australasian Plant Pathology Society conference at Newcastle.
Visits by the entire Bhutanese delegation in the Sydney region included: inspections of the Industry & Investment EMAI facilities and Australian citrus repository; visits to commercial citrus orchards on the central coast of New South Wales; a visit to the Eastern Creek Plant Quarantine Station to look at the operation of quarantine facilities in Australia and how they deal with the movement of plant materials into the country; a visit to Eyles citrus nursery at Kenthurst, to examine nursery production practices and a visit and tour of the Sydney wholesale fruit and vegetable market at Flemington.
In Mildura visits included the Dareton Primary Industries Institute with inspections of the citrus nursery, citrus variety arboretum and research trials investigating rootstock and scion varieties, nutrition and irrigation. A visit to the Auscitrus (citrus rootstock and budwood scheme) facility was undertaken to look at nursery practices along with rootstock seed collection and processing. Following this a local citrus packing shed and a juice processing plant were visited. The production of citrus under netting was also investigated at a local orchard. Irrigation infrastructure managed by Western Murray Irrigation was inspected looking closely at the engineering aspects of the delivery of irrigation water to the region. Two detailed property inspections occurred at a large corporate farming enterprise at Colignan, Victoria and an organic citrus farm at Ellerslie on the Darling River. The group was also taken to the Murray Valley Citrus Board to gain an understanding of the function and role of an industry based organisation.
In October 2009 Bhutanese project officer Mr Phunstho Wangdi undertook one month's intensive training in citrus production at the Dareton Primary Industries Institute. The on-site training program included nursery management, establishment of new citrus plantings, soil moisture monitoring, soil analysis and interpretation, irrigation scheduling, fruit size and yield assessments, canopy management, citrus propagation, fertiliser application, juice extraction and titration testing for maturity and Occupational Health and Safety. Additionally Mr. Wangdi completed two nationally accredited courses in Chainsaw Operation and Safe Use of Chemicals.
A small quantity of gibberellic acid (GA) was supplied to Bhutan in 2008 for trials to assess the effects on mandarin rind quality and fruit maturity. GA is widely used in Australia and overseas to improve rind quality and extend the harvesting season of some citrus varieties. Application of GA was undertaken at the Rimchu demonstration site in conjunction with the Post Harvest group. Another small trial has been undertaken by Mr. Dophu Namgyel a Senior Research assistant based at Yusipang. Preliminary results indicated that treated fruit showed no signs of post harvest breakdown, whereas untreated fruit were infected by moulds - this was an unexpected outcome. The GA trials will again be undertaken in the 2010 season.
Leaf samples collected in Bhutan during a May 2009 pest and disease survey of citrus orchards and nurseries in three of the citrus growing districts of Bhutan, were tested by conventional and real-time PCR for the presence of Huanglongbing (HLB or citrus greening). Samples were analysed in Australia and Bhutan to validate the results in both laboratories and investigate the effect of altitude on disease incidence. Testing of psyllids collected from infected trees during the same sampling trip is in progress. Leaf and psyllid samples will also be used in Australia to update and validate procedures in the national diagnostic standard for HLB.
Leaf samples collected in Bhutan during the May 2009 survey were analysed and tested for powdery mildew. The powdery mildew occurring in Bhutan has now been identified as Odium citri - this is the first report of this species in Bhutan. Previously the powdery mildew in Bhutan had been listed as being O. tingitaninum. A Scientific paper authored by Holford P, Donovan NJ, Thinlay, Kabanoff E, Wildman O, Hardy S, Beattie GAC, Namgay Om, Dorjee, Phuntsho Wangdi titled 'First report of Odium citri in Bhutan' has been accepted for publication in Australasian Plant Diseases Notes.
As part of the project, trial protocols have been developed to undertake testing of sulfur for powdery mildew control in mandarin orchards in Bhutan. These trials are currently being undertaken at several locations to test the efficacy, timing and rates of sulfur against citrus powdery mildew. Sulfur is widely used throughout the world to control powdery mildew in other crops including citrus. However sulfur is not available as a pest/disease control product in Bhutan, so the appropriate product had to be sourced from India by the Ministry of Agriculture.
Trial protocols for the assessment of HMO's against Chinese fruit fly oviposition have also been provided to the National Plant Protection Centre (NPPC), however at present there is no entomologist available to undertake this work. A preliminary trial to evaluate any phytotoxicity effects of HMO's on mandarins under Bhutanese conditions has been undertaken, with results indicating no obvious negative impacts.
During February and March a significant amount of information on technical specifications for building insect proof screen houses was supplied to Dorjee, National Citrus Coordinator and ACIAR Project Leader Bhutan, for a new facility to be built at the Mithun Research Station in Tsirang. Bhutan has received financial support from the UNDP for the establishment of insect proof citrus nurseries and mother block repositories. The information included the technical specifications used by the Florida Citrus Budwood Registration scheme for their new facility recently built at Chiefland.
In April 2010 two project personnel from Australia (Mr Jeremy Giddings and Mr Julian Connellan) travelled to Bhutan to establish a permanent drip irrigation system at the Rimchu demonstration orchard in the Punakha district. In Bhutan the majority of orchards being located on the mountain slopes do not have a permanent water supply on farm. Providing irrigation to tree crops throughout the growing season is uncommon and any watering is usually done by hand. A novel pump which uses stream flow to pump water was sent to Bhutan from Australia. The pump and irrigation system were installed successfully and a demonstration of the pump and irrigation system was held for 25 Bhutanese extension and research officers. A formal training course in soil and irrigation management was also delivered to 25 Bhutanese research and extension officers.