Ducks, drones, and biopesticides: How Asian farmers are using biological control methods to battle climate change

This story was originally published by the Food and Agriculture Organization of the United Nations

Nguyen Thi Thu Huong is not someone who normally breaks with tradition.

The 56-year-old farmer, from Thanh Quoi commune deep within Viet Nam’s Mekong Delta, has strictly followed traditional ways of rice cultivation handed down through generations. These do not include biological control methods. 

But, unlike earlier generations, Huong has witnessed first-hand how the intensifying impacts of climate change now threaten Viet Nam’s rice basket and her family’s way of life.

“Things are not like before. The weather is changing. There are more and different pests. It’s harder to produce crops now,” said Huong, while casting an eye over the five-hectare cluster of emerald-coloured fields where she joins five others each day to toil under the hot tropical sun.

©FAO/Hoang Dinh Nam

Climate change has triggered waves of invasive pests, such as the destructive fall armyworm, and plant diseases like rice blast, leading to a 30 percent annual loss in crops in Huong’s commune. These devastating impacts on crop yields are magnified by the intensifying frequency and severity of climate crisis-driven floods and drought, while saltwater intrusion threatens large swathes of this usually fertile delta.

Looking for a natural solution

For Huong and other farmers in her province, traditional coping strategies, like reliance on chemical pesticides, have only compounded the situation.

Intensive use of hazardous chemicals threatens the health of farmers, consumers, and the environment, with contaminated soil and water harming biodiversity and beneficial insects. Furthermore, dense seeding to offset crop losses is financially costly and resource-wasteful. 

Viet Nam is not alone. Across Asia and the Pacific, agriculture-dependent communities remain acutely vulnerable to climate change. While monoculture cropping systems like rice paddies support 60 percent of regional caloric intake, they are under threat from pests, floods, and heatwaves that erode smallholder annual incomes by between 20 and 40 percent in hotspots, such as the Mekong Delta and Ganges Basin.

©FAO

This makes ecological resilience and community adaptive capacity imperative to counter escalating climate shocks, with 19 percent rice yield declines for key producers like Viet Nam in the past decade set to climb to 30 percent if adaptations are not realized and scaled regionally.

“My family and others here realized the traditional ways of doing things were no longer enough, but now we have a new way,” said Huong.

Natural pest control as a sustainable alternative

By blending indigenous agricultural approaches from past generations with innovations from today, a project by the Food and Agriculture Organization of the United Nations (FAO) is bringing proven country-specific research out of laboratories and into farmers’ fields to tackle the climate crisis with biological control methods. 

The model starts with hands-on training, delivered at Farmer Field Schools, on topics like biological control methods and climate-adaptive cultivation solutions, applying these to demonstration plots for later replication on farms.

In Viet Nam, pheromone traps prevented pests from mating, while ducks released into rice fields controlled pests, weeds, and provided natural fertilizer from their droppings and aerated soil through movement to eliminate the need for chemical pesticides and fertilizers.

The Alternate Wetting and Drying irrigation model maintained stable yields while cutting water use and greenhouse gas emissions. Drones were employed to spray biopesticides and reduce farmers’ labour costs. These biopesticides tackled pests while protecting natural enemies like spiders and pollinators such as bees to ensure biodiversity.  

A 30 percent jump in net profit per hectare has turned Thanh Quoi commune’s farmers into champions of this new way of farming.

New biological control methods implemented by the project have allowed farmers to cut material costs by nearly one-third (29 percent), particularly seeds (50 percent) and fertilizer (23 percent). Biopesticides delivered further financial gains by halving spraying regimes due to healthier crops.

Biological control methods around Asia

In Bangladesh, where invasive pests and diseases accounted for 30 percent annual crop losses, a potent trio of biological control methods was combined to reduce fungal diseases and insect damage across okra crops by between 60 and 70 percent at project sites in Mymensingh district, 120 kilometres north of the capital Dhaka.

© FAO/Giulio Napolitano

This holistic solution combines Trichoderma, a fungus that protects plant roots from diseases, with a predatory mite, Neoseiulus longispinosus, that controls pests, while Trichogramma is a wasp that parasitizes pest eggs to prevent hatching. This integrated approach, effective at all stages of the pest life cycle, improves crop health and reduces the need for chemical pesticides, which are harmful to the environment and to beneficial organisms.

While in Nepal, tomato growers have witnessed a reduction of between 60 and 70 percent in plant diseases. In partnership with Gandaki Province’s Plant Protection Laboratory, the project supported participatory research and the development of the fungus Trichoderma viride, which antagonizes major soil-borne disease-causing pathogens such as Fusarium, while stimulating the tomato plant's immune system to also fight off pests such as the fall armyworm.

In Cambodia, as part of its mission to bridge critical gaps between research, field implementation, and policy reforms, the project created innovative guidelines on the use of pesticides and biopesticides in the country.

By embedding ecological resilience within local communities, farmers now have nature-based knowledge and skills to cultivate agri-food systems for climate-resilient futures.

“These results have completely changed the way I and others farm now and into the future. There is no turning back,” said Huong.

*All images courtesy of FAO 

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