Grafting a healthier tomato in Hanoi
In the capital cities of Asia, where urban growth rates are the highest in the world, the last thing that one might expect to see is lush vegetable gardens. But between its high-rise buildings and colourful temples, the Vietnamese capital Hanoi is, it seems, a very green city. Moreover, Hanoi's green credentials do not only lie in its tree-lined avenues and parks, but in an urban trend to grow vegetables and other agricultural produce in city gardens. A visit to one of Hanoi's busy market stalls reveals a fast trade in city-grown pak-choi, cauliflower and tomatoes. Urban and peri-urban production currently meet around 44 per cent of the capital's vegetable demand, in sharp contrast to some other cities in Asia such as Manila, where urban farming meets only 2 per cent of the city's needs.
Hanoi's tomato challenge
It is not unusual to find tomatoes in Hanoi's vegetable markets, but during the hot months, disease and heavy rains make it almost impossible to grow the crop. Farmers are forced to grow other, less profitable alternatives, such as sweet potato, sweetcorn or rice. But growing tomatoes off-season in Hanoi can increase seasonal profits by up to 60 per cent for city farmers.
To support the production of off-season tomatoes, the Sustainable Development of Peri-urban agriculture in South-East Asia Project (SUSPER) has been working to develop hardier plants, through grafting techniques. Root-knot nematodes, bacterial and fusarium wilt are common pests and diseases that affect summer-grown tomatoes. However, using eggplant roots as the base for the grafted tomatoes overcomes these problems. Eggplant roots are also flood tolerant, allowing the crop to tolerate waterlogged soils, and to survive flooded conditions for up to a week.
According to Le Chong Tan, deputy head of Hanoi's Le Phap co-operative, grafting the tomato vine onto eggplant roots has not only created a hardier variety, but one which sells better even during the peak tomato season. Le Chong attributes this to their healthy colour and shape, and the fact that they stay ripe for longer once removed from the vine. Farmers in the co-operative have been given guidelines by SUSPER, to ensure successful grafting and cultivation. The project, together with the Research Institute of Fruits and Vegetables (RIFAV), has also introduced the grafting technology into northern Vietnam, and has partnered with the Hanoi Seed Company to mass-produce grafted tomato seedlings for farmers.
Supporting city farming
Launched by CIRAD and other partners, such as the World Vegetable Center (AVRDC), the SUSPER project focuses on the huge potential offered by urban farming to meet the challenges presented by urban population growth. In contrast to rural farmers, city farmers can benefit from high returns, good access to markets and a better understanding of consumer tastes. The sector also provides employment for unskilled labour, especially for women, as well as creating green spaces. In Vietnam, SUSPER has raised awareness of urban farming among urban planners and city authorities and has promoted the tomato grafting technology on national television. The broadcast aired on the VTV2 channel in Vietnam followed the entire production procedure, from transplant to yield.
Supporting city farming can also have wider positive impacts. Socio-economist Mubarik Ali from AVRDC, argues that peri-urban agriculture does not only provide cities with fresh vegetables such as tomatoes, it can also can have broader consequences for agricultural production. "With appropriate policy support," he says, "the peri-urban system will pull up the rural agricultural production system to its level. Without policy support in the urban system, the rural system will be left leaderless."
Environmental threats and opportunities
There are, of course, some dangers associated with urban horticulture. Pesticides and fertilisers may become a cause of pollution if left unregulated and heavy metal contamination in foods is more likely than it is in rural areas. There is also intense competition for scarce resources such as land and water. However, urban farming has the potential to recycle city waste. One report released by CIRAD and AVRDC, notes that if manure in the city is managed properly, it could meet up to 57 per cent of Hanoi's urban and peri-urban demand, where currently there is no waste disposal facility.
Manuel Palada, a Crop and Ecosystem Management Specialist at AVRDC, believes that urban and peri-urban agriculture have good potential to provide "fresh food, at a cheap price, and create jobs for the unemployed population." But he also warns that it must "blend well with overall urban development by not competing for use of resources, especially water." For residents of Le Phap in Hanoi city tending their tomatoes, 90 per cent say their income has improved since selling grafted tomato varieties.
Date published: March 2007
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