Pesticide residues are a major concern in imported and locally produced vegetables. With the introduction of this state-of-the-art technology, Cambodia has become one of the first countries to embrace this highly innovative rapid pesticide residue detection technology that will strengthen the country’s efforts in tackling food safety issues in fresh foods such as vegetables and fruit.

On 6 March, Monthivuth Ker, Director of the Department of Plant Protection Sanitary and Phytosanitary of the Ministry of Agriculture, Forestry and Fisheries (center right), takes receipt of the new portable SERS pesticide residue testing machine from Srinivasan Ramasamy of the World Vegetable Center (center left), in the presence of other ministry officials.

This was made possible through a project that is boosting safe and off-season vegetable production in Cambodia and Laos, funded by the German Federal Ministry for Economic Cooperation and Development. Implementation is led by the World Vegetable Center, in partnership with the General Directorate of Agriculture, East-West Seed-Knowledge Transfer, and iDE in Cambodia, and in Laos with the Clean Agriculture Standards Center of the Lao PDR Department of Agriculture.

No one wants to eat unsafe food, though modern agriculture relies heavily on chemical inputs. In cash crops such as vegetables and fruit, farmers use pesticides as an insurance to ensure their harvests and income. But they often use more than is required. In Cambodia, vegetable growers use a mixture of three to four pesticides in each spraying, often weekly, sometimes even twice a week. And, pesticides do not dissipate to safe levels for consumption when farmers do not provide an adequate interval between the last spraying and harvesting.

To make sure harvested produce is safe for consumption, there are pesticide residue testing methods that can identify even micro amounts. However, this analysis requires sophisticated equipment and specialized operators and takes even a few days to get the results. Needless to say, such testing methods are expensive, and facilities are available in limited quantities or access to most users in the developing world. Scientists have been trying to develop rapid pesticide residue testing methods to overcome these shortfalls. Most previous attempts were enzyme-based, detecting only a few selected groups of pesticides, and results indicate what is present but not how much is present, only a possible range.

But in a groundbreaking development, Taiwanese scientists at the Agricultural Chemicals Research Institute (ACRI) of the Tawan Ministry of Agriculture have pioneered a cutting-edge qualitative and semi-quantitative method for rapid pesticide residue testing. This ‘Surface Enhanced Raman Spectroscopy’ or SERS method can detect up to 230 different pesticides within minutes. ACRI has licensed the manufacture and sale of this technology and the reagents to a private company in Taiwan, Phansco. Most importantly, the system is portable and cheap to operate, with each sample costing less than one-tenth that if using other pesticide residue testing methods. Phansco will also support Cambodian ministry staff with training.

“Food safety begins at farm level, and this equipment will help us so much” said Monthivuth Ker, Director of the Department of Plant Protection. “It is small in size, but will be make a large difference and is very precious to us”.

“The SERS equipment not only revolutionizes rapid pesticide residue testing but also addresses accessibility issues by providing a portable and cost-effective solution, ensuring safer harvests for farmers in the developing world such as Cambodia and Lao PDR”, adds Srinivasan Ramasamy, Lead Entomologist, and Flagship Program Leader for Safe and Sustainable Value Chains at World Vegetable Center.

The Grow Against the Flow project is funded by the German Federal Ministry for Economic Cooperation and Development, and implemented by WorldVeg and East-West Seed-Knowledge Transfer (EWS-KT), in partnership with the General Directorate of Agriculture in Cambodia, iDE, and the Clean Agriculture Standards Center of the Lao PDR Department of Agriculture.