Managing pest fruit flies to increase production of fruit and vegetable crops in Vietnam

Vietnam is one of many countries in South East Asia which experience serious preharvest fruit and vegetable losses to fruit flies ranging from 70 - 100%. As a result, fruit flies are seen as a major contributor to the ongoing problems of hunger, poor nutrition and poverty, especially in the rural communities, which comprise over 75% of Vietnam's population. The purpose of the project is to develop and introduce simple yet practical, in-field solutions to the fruit fly problem that will result in a direct and positive influence on household and food security for Vietnam.

The key collaborating institutions in Vietnam are the Ministry of Agriculture and Rural Development (MARD) through the National Institute of Plant Protection (NIPP) in Hanoi, the Southern Fruits Research Institute (SOFRI) at Long Dinh, the Provincial Plant Protection Departments (PPPD), Foster's Asia (Tien Giang Brewery) and AVENTIS Crop Science (Vietnam office). Collaboration within Australia is with Foster's Brewery, Melbourne, AVENTIS Crop Sciences and the Crawford Fund.

The various components of the project are progressing well and have yielded good results as follows:
Surveys of fruit flies in Vietnam are being conducted through trapping and host fruit collecting. These surveys have revealed nine species of fruit flies as being of major economic importance, along with another 20 non-pest species in Vietnam.
Studies to define the pest species of fruit flies, their geographic and host ranges, and levels of damage to major food crops have shown that crops such as gourds and water apple experience losses in excess of 95% in unprotected situations.
The construction of a protein manufacturing plant at Foster's Brewery, Tien Giang, although initially delayed, has now been completed and the necessary equipment (yeast waste evaporator, digestor and drum dryer) has been installed. Production of protein from the brewery yeast waste is expected to commence in the final quarter of 2002.
As an interim measure, Vietnamese collaborators were taught the procedures and have begun processing Foster's Brewery waste into protein bait in the laboratory at SOFRI. This laboratory prepared bait is being used for the scheduled laboratory and field tests to determine the correct formulations and application rates for the new protein product for efficient use in fruit fly control programs.

The first of three training workshops planned for the project was conducted in SOFRI from 3 - 7 June 2002. The purpose of the workshop was to train a core group of Vietnamese trainers who will then conduct further training for other Vietnamese staff, especially Plant Protection Sub-Department staff. A comprehensive training manual covering morphology, taxonomy and management of fruit flies in Vietnam was prepared and distributed to all participants. A total of 27 participants from 12 different agencies in Vietnam attended the training workshop. A major outcome of the workshop was the design of a brochure in the Vietnamese language by workshop participants for local farmers on fruit fly identification, biology and management. This brochure is to be produced by NIPP and SOFRI and widely distributed to Vietnamese farmers. The circulation of this farmer brochure will be made in conjunction with the release of the new protein bait from Foster's Brewery at Tien Giang.

Extensive collections of adult fruit flies collected from male lure traps and reared from host fruits (cultivated and wild) over 23 provinces covering north, central and south Vietnam have revealed that there are nine species of fruit flies are of economic importance to horticultural production and export trade in Vietnam. These are Bactrocera dorsalis, B. carambolae, B. correcta, B. cucurbitae, B. diversa, B. latifrons, B. pyrifoliae, B. zonata and B. tau. The species causing the greatest damage in north Vietnam are B. dorsalis, B. pyrifoliae and B. cucurbitae, whereas in south Vietnam the species causing greatest damage are B. dorsalis, B. correcta and B. cucurbitae. Crop losses ranging from 40 to 100% are being recorded in a wide range of fruits and vegetables when no control measures are applied.

To assist with field control studies, laboratory colonies (rearing on artificial diet) of B. cucurbitae have been established at the National Institute of Plant Protection (NIPP). Colonies of two other major pest species-B. dorsalis reared from litchi and B. pyrifoliae reared from peach are also being set up at NIPP. At the Southern Fruits Research Institute (SOFRI) colonies of pest species B. correcta and B. dorsalis have been successfully established. These laboratory colonies currently provide adult flies for laboratory and field testing of the new protein bait produced at Foster's Tien Giang brewery.

The production plant at Foster's Brewery at Tien Giang to process brewery waste into a fruit fly bait has been fully commissioned. Batches of protein bait produced at the plant are currently being evaluated by NIPP for field control of fruit flies infesting peach and bitter luffa, and by SOFRI on water apple and guava.

An extensive training program for on the biology and control of fruit flies for Provincial Plant Protection Department (PPPD) staff, as well as for farmers has been successfully implemented in various provinces around Vietnam. Project staff from Brisbane initially ran a week-long workshop in June 2002 to train a core group of trainers from NIPP, SOFRI, PPD and selected universities in Vietnam. These staff members from NIPP and SOFRI have subsequently completed training a total of 177 PPPD staff as well as 1600 farmers from 16 provinces across Vietnam. The training was accompanied by the distribution of over 3000 illustrated brochures in the Vietnamese language on the biology and management of fruit flies, incorporating the new bait spray technology.

Continued collections of adult fruit flies collected from male lure traps and reared from host fruits (cultivated and wild) over various provinces covering north, central and south Vietnam have not revealed any new pest species beyond the nine that have so far in the project been identified as being of economic importance to horticultural production and export trade in Vietnam. These are Bactrocera dorsalis, B. carambolae, B. correcta, B. cucurbitae, B. diversa, B. latifrons, B. pyrifoliae, B. zonata and B. tau. In the current sampling period, however, B. correcta has also been recorded in North Vietnam where it was not recorded before. Crop losses ranging from 40 - 100% are still being recorded in a wide range of fruits and vegetables when no control measures are applied.

Laboratory colonies (rearing on artificial diet) of B. cucurbitae at the National Institute of Plant Protection (NIPP) and B. correcta and B. dorsalis at the Southern Fruits Research Institute (SOFRI) continue to be maintained. These laboratory colonies currently provide adult flies for laboratory and field testing of the new protein bait produced at Foster's Tien Giang brewery.

The protein bait production plant at Foster's Tien Giang has been fully commissioned and was officially launched together with the bait called SOFRI PROTEIN on 16 April 2004 by the Australian Ambassador to Vietnam, the Hon Joe Thwaites. The high profile ceremony was attended by senior officials from the Tien Giang provincial government, Ministry of Agriculture and Rural Development (MARD) Vietnam, Fosters Brewing International, Griffith University, Queensland Government, AusAID and ACIAR.

The one-day training program for farmers on the biology and control of fruit flies for Provincial Plant Protection Department (PPPD) staff, as well as for farmers has been successfully continued. In South Vietnam, training in this reporting period has focussed on Barbados Cherry farmers with whom an large area fruit fly control program is being organised. Over 4,000 copies of farmer extension leaflets have been printed and distributed by NIPP and SOFRI.

To ensure more effective control of fruit flies, two large-area fruit fly control programs have been implemented, one on peach grown by minority hill tribe people in Moc Chau, North Vietnam, and the second in Barbados cherry grown largely in Tien Giang province in South Vietnam. These trials combine the use of male lures with SOFRI PROTEIN bait sprays for more effective fruit fly population suppression. Farmers are organised in large groups of 25 or more and apply these treatments in a coordinated manner. Initial results show excellent suppression of pest fruit fly populations and very low levels of fruit damage to the benefit of a large number of farmers in an area.

SUMMARY FROM FINAL REPORT:
Extensive collections of adult fruit flies obtained from male lure traps and reared from host fruits (cultivated and wild) over 23 provinces covering north, central and south Vietnam have revealed that there are eight species of fruit flies are of economic importance to horticultural production and export trade in Vietnam. These are Bactrocera dorsalis, B. carambolae, B. correcta, B. cucurbitae, B. latifrons, B. pyrifoliae, B. zonata and B. tau. The species causing the greatest damage in north Vietnam are B. dorsalis, B. pyrifoliae and B. cucurbitae, whereas in south Vietnam the species causing greatest damage are B. dorsalis, B. correcta and B. cucurbitae. Crop losses ranging from 40 - 100% are being recorded in a wide range of fruits and vegetables when no control measures are applied.

To assist with field control studies and other ACIAR funded projects to improve postharvest fruit quality, laboratory colonies (rearing on artifical diet) of B. cucurbitae B. dorsalis and B. pyrifoliae were established at the National Institute of Plant Protection (NIPP). At the Southern Fruits Research Institute (SOFRI) colonies of pest species B. correcta and B. dorsalis were successfully established. These laboratory colonies provide adult flies for laboratory and field attractancy testing for on-going quality control of the new protein bait produced at Foster's Tien Giang brewery.

The protein bait production plant at Foster's Tien Giang was officially launched on 16 April 2004 by the Australian Ambassador to Vietnam, the Hon Joe Thwaites. The ceremony was attended by senior officials from the Tien Giang provincial government, Ministry of Agriculture and Rural Development (MARD) Vietnam, Fosters Brewing International, Griffith University, Queensland Government, AusAID and ACIAR, as well as over 200 local farmers from the surrounding provinces. The protein product has been officially registered in Vietnam under the trade name SOFRI Protein 10DDD (yeast protein + fipronil insecticide) and is being made available for sale to farmers through a local pesticide distribution company that has numerous outlets in the Mekong delta. The price has been kept very low and is controlled by a steering committee comprising Griffith University, ACIAR Vietnam, SOFRI, Foster's Tien Giang and Cantho Pesticide Company. The protein production plant at Foster's Tien Giang has an annual production capacity of about 50,000 litres of protein.

The use of SOFRI Protein 10DD both in small farms and over large areas has provided excellent control of pest fruit flies across a range of fruit and fruiting vegetable crops in Vietnam, resulting in major increase in incomes for farmers. For example, H'Mong minority hill tribe people in the northern province of Son La, Moc Chau district cultivate peach as their main crop but have always had to harvest the fruits hard green because ripe fruits are 100 per cent infested by fruit flies. Using the spot spray protein bait technology, fruit fly damage was reduced to less than 5 per cent, resulting in farmers harvesting ripe fruits from which they obtained higher yields and better prices. Overall this resulted in a 4-fold increase in incomes in one season for the peach farmers. Barbados cherry farmers in Go Cong province in the Mekong Delta have also experienced a similar benefit with a 2-fold increase in incomes resulting from higher yields in orchards using SOFRI Protein 10DD. Control trials in other crops like guava, jujube, luffa and bitter gourd have reduced fruit fly damage from over 70 per cent to less than 5 per cent. The protein bait spot spray technique also provides major health and environmental benefits by utilizing extremely low amounts of pesticide and spray volumes in comparison with cover sprays of insecticides. The Ministry of Agriculture and Rural Development now plans to set up more protein production plants in other breweries across the country and extend the benefits of the protein spot spray bait technology to the wider farming community in Vietnam.

An extensive training program on the biology and control of fruit flies for Provincial Plant Protection Department (PPPD) staff, as well as for farmers has been successfully implemented in various provinces around Vietnam. Project staff from Brisbane initially ran a week long workshop in June 2002 at SOFRI to train a core group of trainers from NIPP, SOFRI, PPD and selected Universities in Vietnam. These staff from NIPP and SOFRI have subsequently completed training a total of 290 PPPD and sub-PPPD staff as well as 4445 farmers from 16 provinces across Vietnam. The training was accompanied by the distribution of over 5000 illustrated brochures in the Vietnamese language on the biology and management of fruit flies, incorporating the new protein bait spray technology introduced by the project.

Year 5 report not sent due to a gap between final report and new variation.

Year 6 progress summary is for the period 1 May 2006 - 30 April 2007.
1. Pairs of male lure traps (methyl eugenol and cue-lure) were set up in provinces that were not surveyed before. These are Kien Giang, Thua Thien Hue, Ca Mau, Tra Vinh, An Giang and Binh Phouc in South Vietnam, and Son La, Thai Nguyen, Tuyen Quang and Ha Giang in north Vietnam. No new species of flies have been recovered so far and the species composition remains the same as for the provinces surveyed in the earlier project. Additional samples of host fruit have been collected to verify uncertain host records.

2. Trials on peach and plum integrating fruit fly control using spot sprays of protein baits with improved crop management techniques and post-harvest handing introduced through ACIAR project CP/2002/086 - Improving postharvest quality of temperate fruits in Vietnam and Australia were planned for various locations in Moc Chau province. However, these trails could not be implemented this year because of high variability in fruiting and fruit load within some of the experimental sites. It is thus proposed to conduct these trials during the next fruiting season in March - June 2008.

In the Mekong Delta, trials were planned to integrate fruit fly control using spot sprays of protein baits with improved control of pests other than fruit flies using white mineral oils introduced through ACIAR Project CP/2000/043: Huanglongbing management for Indonesia, Vietnam and Australia. One trial on Barbados cherry has been established to evaluate the effectiveness of integrating SOFRI Protein and methyl eugenol trapping for fruit fly control, and the mineral oil SK Enspray 99 for other such as aphids, mites, scales and mealy bugs. The trial is in progress.

A new protein bait plant has been constructed at An Thinh Brewery in Hanoi, and the facility was officially launched on 9 May 2007.

3. The farmer training programme is continuing with another 2950 farmers having received training in fruitfly biology and field pest management in the provinces of Hue, Quang Nai, Quang Nam, Lam Dong, Contum, An Giang, Kien Giang, Ca Mau, Soc Trang and Bac Lieu.