Vietnamese rice farmers have been using fragrant flowers to save their crops from pests, experts at a conference in Hanoi said Friday.
Farmers in the Mekong Delta’s An Giang province have been growing banks of yellow and white nectar-rich flowers along their paddy fields since August to attract wasps that prey on the brown planthopper, which destroys thousands of hectares of paddy each year.
The adult wasps feed on the nectar of the flowers, but they plant their eggs in the adult planthoppers, which are destroyed when the larvae hatch. ”By growing these flowers the parasites have resources to hide and feed, thus providing protection for preventing outbreaks of the brown planthopper,” ecologist K L Hoeng told dpa.
The project, launched by the International Rice Research Institute (IRRI), was hailed as a good example of ecological engineering by experts attending the IRRI conference, titled Threats of Insecticide Misuse in Rice Ecosystems - Exploring Options for Mitigation.
The flower-based project does not even require importing new plant species, Heong said. ”We are just asking farmers to propagate what already exists in their rice fields.” Excessive insecticide use has led to a decline of the wasps and other natural predators of the planthoppers, experts say, leading to a surge in the numbers of the pest, which resembles a small locust.
Vietnam is the world’s second-largest rice exporter behind Thailand. In June, Bangkok banned the use of two pesticides, bamectin and cypermethrin, in a bid to bring back the planthoppers’ predators. In 2009, around 300,000 hectares were heavily infested in China and Vietnam, and more than 6,500 hectares suffered complete crop failure from the pest.
