10. DECIDUOUS FRUIT PRODUCTION IN VIETNAM

Philippe Cao-Van* and Nguyen Minh Chau**

* Centre de Cooperation Internationale en Recherche Agronomique pour le Development, Department des Productions Fruitieres et Horticoles (CIRAD-FLHOR), c/o Southern Fruit Research Institute, Vietnam.

* Southern Fruit Research Institute, PO Box 203, My Tho, Tien Giang, Vietnam

Many deciduous fruits originated from South-East Asia and for this reason these fruits are still being cultivated in the highlands of Vietnam. These are currently grown in the provinces of Ha Giang, Cao Bang, Lai Chau, Lao Cai, Tuyen Quang, Lang Son, Bac Thai, Son La, Vinh Phu, Quang Ninh, Hoa Binh and also in the Dalat region (Lam Dong province) in the South (Table 1). During the French colonial occupation, some of the native cultivars were studied and described by Mieville (1921) and Chevalier (1923). Several European cultivars were introduced during that time but disappeared later.

Deciduous fruits are cultivated today by the ethnic minorities who inhabit the mountainous areas. Large areas are in production but traditional practices have prevented any improvement in yield and quality. These crops, however, present an important challenge to the Government which would like to achieve the following:

- improve the living conditions of ethnic groups and fight against poverty;
- satisfy a greater part of the domestic demand for deciduous fruits;
- modernize traditional production practices and intensify production systems;
- discourage the production of the prohibited opium poppy crop;
- encourage the ethnic groups to engage in settled agriculture instead of resorting to destruction of forests from their shifting cultivation practices.

2. PRESENT SITUATION OF DECIDUOUS FRUIT CROP CULTIVATION

Various deciduous fruit species are grown in the highlands of the country. Some information on these species is given below:

2.1 Japanese Plum (Prunus salicina)

Only this species or its hybrids are grown in Vietnam between 700-1000 m altitude. The Japanese plums are produced only for the domestic market. Three cultivars, namely, Man Tam Hoa, Man Hau and Man Duong predominate. In fact, these three cultivars appear to be from one main variety that originated in South China. They all have the following disadvantages:

- lack of a long harvest period, which leads to a serious oversupply to local markets, and a sudden drop in prices immediately after the harvest in June;

- they have small-sized fruit (average fruit size is 20-30 mm);

- they have very poor keeping quality.

Table 1. Acreage of Fruit Crops in 1995 and Planned Acreage for the Year 2010 for 11 Mountain Provinces (in hectares)

Province	1995 (ha)	2010 (ha)
Ha Giang	3,503	10,000
Tueyen Quang	1,070	7,000
Cao Bang	720	6,000
Lang Son	3,290	10,000
Lai Chau	560	8,000
Lao Cai	2,690	6,000
Yen Bai	720	7,000
Bac Thai	10,780	10,000
Son La	5,557	12,000
Hoa Binh	833	10,000
Quang Ninh		14,000
Total	32,443	100,000

Source: Research Institute of Fruit and Vegetables, Vietnam (RIFAV)

This fruit is smaller than the European apricot (Prunus armeniaca) but it is an old introduction and its cultivation is widespread in the country. Due to its hardiness, it has been recommended in the past, particularly for reforestation programs. In 1993, this crop occupied an area of nearly 1638 ha in the North-East and was second only to citrus. The fruit has some potential as a fresh fruit as well as for processing into dried fruit which has a ready market. The principal cultivars of Japanese apricot are Mo Vang Bach Thong (yellow apricot), Mo Vang Moc Chau (yellow type) and Mo Ma Dao (Pink apricot).

2.3 Peach (Prunus persica L.)

This fruit species has its center of origin in South-East Asia and is cultivated above 700 m altitude in North Vietnam. It is well adapted to local climatic conditions and is moderately resistant to several diseases. Under good growing conditions, cultivars like Hmong peach or Dao Meo can produce reasonably large fruits like the European types, but most locally grown cultivars give small fruit and have a very short harvest season. In addition to a selection program for this species, it is also necessary to improve the cultural practices. For future introductions, emphasis should be given to low chilling cultivars which would allow expansion of existing areas where humidity may be a limiting factor. A testing program for apple, peach, plum and apricot at Bac Ha in Lao Cai province in 1991, carried out under the auspices of FAO, showed that a peach introduction from Bulgaria (cultivar DA2) performed well (Tranh, 1996). Other promising peach cultivars were Dao Sapa and Dao Mau Son.

2.4 Asian Pear (Pyrus pyrifolia)

Introduced into Vietnam from China many years ago with the Hmong migrations in the 1960s as well as through a cooperative bilateral program, the species spread into many parts of the mountainous areas. The spread of this species is, however, limited as it has a short harvest season. Other species of limited adaptability are Pyrus pashia which gives fruits of poor quality and some hybrids of Pyrus communis x P. pyrifolia such as the Kieffer pear introduced by Mieville in 1921. This late hybrid has low chilling requirements, moderate tolerance to fire blight (Erwinia amylavora), intermediate quality as a fresh fruit and good cooking quality. The principal pear cultivars are Le Tao and Le Duong which are both derived from P. pyrifolia species.

2.5 Apple (Malus doumeri)

A semi-wild species which has spread from North to South in areas above 1400 m altitude is popularly called the Meo apple. It is well adapted to local conditions and is highly resistant to many diseases. It is a tall variety which is well adapted to agro-forestry programs and grown on an orchard scale. Its fruits are smaller and of poorer quality than Malus domestica. This species has, however, never been subjected to any selection programs or application of any modern production techniques such as the use of rootstocks and pollinators, pruning etc. to improve production.

In 1995, several varieties of Malus domestica were introduced into Sapa State Farm in Lao Cai province at an altitude of 1500 m. The initial successes motivated the Government to formulate a development project for improvement of deciduous fruits. The cultivars Fuji and Granny Smith were found to perform well when grafted on M9 rootstock (Tuyen, 1997). The market for apple is assured all year round and current demand is met by imports from China, USA, New Zealand and Europe.

2.6 Persimmon (Diospyros kaki)

This fruit is traditionally cultivated in all areas of the country above 700 m altitude and is popular among consumers. Its strong astringency is normally controlled by selection of good quality cultivars or by several post-harvest treatments. The most popular cultivars are Hong Thach That, Hong Son Duong, Hong Li Nhan, Hong Luc Yen, Hong Bao Lam and Hong Kuan Ba. There are also many more cultivars grown in the South in Lam Dong province.

3. PRODUCTION OF PLANTING MATERIAL

Only a few ethnic communities have mastered the technique of grafting in some private nurseries. In general, most of the deciduous fruit plants are propagated by seedlings and in some instances by marcottage that does not yield sufficient planting material in quality. Lack of good planting material is the main limiting factor to expansion of deciduous fruit production. In the Bac Ha region (Lao Cai province), however, peach is propagated by grafting, but budding techniques are not used at all. The lack of expertise in grafting/budding is also a serious impediment to research studies on virus transmission and control of common virus diseases. Whilst vegetative propagation techniques are frequently practiced on mango, citrus and lychee, they are only recently introduced and developed for deciduous fruits at the Sapa state farm. Although the price of grafted planting material is only 20-40 US cents/plant, it provides a substantial income to nurserymen. Since 1996, researchers, extension staff and nurserymen have been trained in modern propagation techniques under a technical assistance program sponsored by CIRAD-FLHOR. Although these activities are currently insufficient to meet local demand for planting material, a start has been made by introducing rootstock seed for training and demonstration in propagation and production of disease-free certified planting material.

4. ESTABLISHMENT OF ORCHARDS

There is no significant preparatory work in the establishment of orchards. The practices followed leave much to be desired. Even the soil preparation to establish new orchards is somewhat superficial, preparing small planting holes to receive new plants. The plant density is often 400 trees/ha at a spacing of about 5m x 5m.

5. CARE AND MANAGEMENT OF ORCHARDS

Management of the orchards consists mainly of the control of weeds and application of fertilizers, which depends on the level of resources available to farmers. Pruning and training techniques are virtually unknown to most farmers. As a result, trees have a multitude of branches and fruit loads on trees are not controlled, resulting in smaller fruit and poorer yields. However, local cultivars can survive under poor management although the quality of fruit is deplorably low.

In the same way, very little effort is made to control pests and diseases even if they are identified and well known to researchers. Although systems of pest and disease control is the mainstay of the agricultural practices in Vietnam for other crops, the situation is still unsatisfactory for deciduous fruits. Since these species are highly sensitive to high humidity prevailing in many fruit growing areas, the control of pests and diseases becomes problematic. The presence of pests, particularly fruit fly (Dacus sp.) appears to be a serious problem. In the case of peach, fruit fly attacks are severe at the beginning of the fruiting season. Fruits that appear normal, harbor the larvae that destroy the fruits. The pest has not been studied well enough to recommend any effective control measures. Population dynamics, life cycle, chemical and biological control mechanisms and economic significance need to be properly assessed to control the spread of the pest.

The status of viral and bacterial diseases is uncertain. Recent interest on deciduous fruits and the lack of understanding of the serious phytosanitary risks due to introduction of foreign material could make the present situation much worse. These risks are even underplayed by responsible researchers. This attitude has been brought home by those researchers who received their training in Central Europe. Consequently, the past introductions of crops like plum from Bulgaria, from an area notorious for high infection pressure from Sharka viral disease, have been conveniently ignored. This material has already been released to most parts of North Vietnam from the Bac-Ha Station.

6. INTERCROPPING

Most deciduous fruit orchards are intercropped with special vegetables called ‘Cai Meo’ during the first three years after establishment. These crops give growers an income until the bearing of the trees commences and orchards become economically viable.

7. HARVESTING AND MARKETING

Apart from poor crop management practices, the situation becomes worse at harvest time. Fruit maturity is determined only by the arrival of a prospective buyer. Consequently, fruits are harvested immature and the situation gets exacerbated by the lack of facilities for handling, lack of temporary storage and equipment for packing and temperature control, inaccessibility of fruit farms to roads and communications etc. Quite often, fruits are harvested 3-8 weeks before ripening stage. This often results in considerable losses. Primitive packing devices such as used fertilizer bags carry immature fruits to Hanoi market from long distances. Under these conditions of low quality, rich consumers resort to purchase of imported fruit. The plum and peach crop is also marketed as dried fruit that is processed in traditional ways. For most of these reasons, deciduous fruits can only find a domestic market. In the summer months, apricot juice is a popular product preferred by most consumers.

8. POTENTIAL AND CONSTRAINTS IN DECIDUOUS FRUIT PRODUCTION DEVELOPMENT

The climatic conditions in the mountainous areas of Vietnam above 700 m altitude provide sufficient chilling for the production of several deciduous fruits. The range of cultivars presently available with the production system should be widened in order to spread the harvest season and produce quality fruits. Emphasis should be placed on the testing and popularization of low-chilling cultivars which are currently available in the world germplasm collections elsewhere. A systematic program of introduction of certified virus-free material should be undertaken under strict quarantine regulations and a vigorous testing under varying conditions needs to be carried out.

Introduction and testing should also be followed by training in nursery techniques and orchard management with assistance from countries with better resources and technologies in growing deciduous fruits in tropical highlands. Pest and disease control methods should also be included in such training programs.

Since the communication network in the country has already been improved, other aspects of the industry such as skills in handling, storage and processing should be developed through cooperative programs with other countries in the region.

The demand for deciduous fruits already exists and the domestic market should be supplied with new and better produce at reasonable prices. For these reasons and the existence of a potential future for the deciduous fruit industry, the Vietnamese Government has drawn up plans and targeted an expansion program for 100,000 ha in the Northern highlands during the next decade (2000-2010).

9. GOVERNMENT POLICIES AND PLANS FOR RESEARCH AND DEVELOPMENT OF DECIDUOUS FRUITS

Within the framework of the development program in the highlands, the Vietnamese Government has placed a high priority on fruit crop expansion which has already recorded a positive impact on the income of farmers. The advantage of the unique ecological conditions in the highlands will be profitably exploited by growing deciduous fruit crops that require a degree of chilling for successful production.

Several surveys conducted jointly by CIRAD-FLHOR experts and the Ministry of Agriculture have highlighted many limiting factors confronted in the mountainous areas. Based on these problems, the Government has requested assistance from the World Bank through a project proposal for deciduous fruit crop development. This Pilot project for fruit crop development in the Northern areas of Vietnam has been agreed upon by the World bank for funding, totaling a sum of US$1,090,000 for a 5-year period. The project involves also other crops in addition to deciduous fruits. It involves all aspects of production development, including the establishment of experimental sites in five provinces of the North (Son La, Lang Son, Lao Cai, Vinh Phu and Bac Thai). In addition, the Ministry of Agriculture and Rural Development (MARD) is expanding its activities through an Apple Development Project for the Sapa state farm, where nearly 200 ha are being developed for the production of apple by the year 2000. The outputs from this research and development program will help farmers in high altitude areas of Vietnam.

10. CONCLUDING REMARKS

Development of deciduous fruit crops is a challenge that the ethnic minorities are undertaking with the assistance of the Vietnamese Government. In terms of socio-economic impact, these development programs will improve the efficiency of farmer production systems and bring about an enhancement of incomes to the farmers. The Government also hopes to solicit the assistance of developed countries to transfer production skills through training and demonstration. The introduction and adaptation of low-chilling cultivars as well as the transfer of new technologies would be an essential component of this program. The behavior of such cultivars need to be critically assessed under Vietnam conditions. It is also envisaged to launch a hybridization program using the introductions and the locally popular hardy cultivars to improve yield and quality.

CIRAD has already embarked on a cooperative program with MARD for deciduous fruit research and development. This program involves germplasm introduction, improvement of local skills in production techniques, and generation of technology to suit local conditions.

REFERENCES

Blanchet P., Ha Minh Trung, Bourdeaut J., 1997. Le adaptation des fruitiers temperes au Vietnam - 1, Le besoin en Froid.

Blanchet P., Ha Minh Trung and Bourdeaut J., 1997. Inventaire des resources genetiques des rosaceec fruitieres du Vietnam. -1. Poiriers Fruits, Vol 52 -1, 9p.

Tuyen Nguyen Danh, 1997. Project on apple development in Sapa.

1997. Fruit Crops. Report of a Mission, 18 Jan. to 03 Feb. 1997.

1997. Training on Deciduous Fruit Crops. Report of a Mission, 27 Sept. to 10 Oct. 1997.

Patrice Blanchet, 1996-97. Pilot project for fruit crop development in the Northern regions of Vietnam. Legta de Montauban - France.

Tranh Nguyen Chien. 1996. Performance of deciduous cultivars in Bac Ha, Lao Cai under the auspices of FAO, 1991 (in Vietnamese language).

1996. Cooperation on Deciduous Fruit Crops. Report of a Mission, 04-22 August 1996.

1996. Deciduous Fruit Crops. Report of a Mission, 22-29 November 1996.