Biocontrol agents for sustainable Cambodian agriculture

In order to meet the food needs and expectations of a steadily growing global human population, crop production will have to constantly increase. The need of external inputs is definitely apparent, especially with regards to chemical pesticides that promise crop protection and yield improvements.

However, most farmers are insufficiently trained in the selection and use of pesticides, which, as a matter of fact, has led to pesticide resistance and pest resurgence caused by the impact of broad-spectrum insecticides on natural enemies, environment and public health. Remember, when your plants are healthy, they can certainty provide a good harvest. So the plants need proper nutrition, water with regular observation of the crop and timely, targeted intervention with the right amount at the right time.

Against this backdrop, GIZ’s ASEAN Sustainable Agrifood Systems (ASEAN-SAS) project has brought together experts from ASEAN member states (AMS) to provide their experience in the use of biological control agents (BCA), which are defined as beneficial living organisms that fight against pest and diseases in rice, vegetables and fruits. BCA act naturally, are environmentally friendly and non-toxic, self-replicate and target specific enemies. BCA are most applicable in the context of appropriate integrated pest management (IPM) strategies that emphasise preventative pest management.

In February 2016, ASEAN-SAS in collaboration with the Cambodia Horticulture Advancing Income and Nutrition (CHAIN) project, a project mandated by the Swiss Agency for Development and Cooperation (SDC) and the private sector companies Eco-Agri Center and Angkor Green, organised a Training of Trainers (ToT) course on the use of BCA. The ToT was provided to 131 participants including agricultural extension and NGO staff, key farmers, the Provincial Department of Agriculture (PDA) and Provincial Department of Women Affair (PDoWA)’s representatives in four provinces: Kratie, Stung Treng, Preas Vihear and Oddor Meanchey.

Participants reported that the most pressing issues for their farming activities have been plant diseases such as damping off, wilt, root rot and downy and powdery mildew that was attacked by fungal pathogens. Some of them applied fungicides to control the issue but the outcome was not satisfactory.  It is assumed that the pathogens have already developed resistance and require increased dosage of pesticides, which may drive farmers into economic hardship.

For sustainable farming, Trichoderma was introduced to address the issue. It is used as a BCA against several pathogenic fungi that cause soil-, leaf- and flower-borne diseases in agricultural plants. It acts to suppress pathogens by producing enzymes and antibiotics while causing no harm to beneficial organisms. Trichoderma is used as a root growth promoter and applied through mixing with compost and seed coating, and by spraying on crop residues for decomposing and inoculating via drip irrigation. Based on numerous field demonstrations in different provinces of Cambodia, Trichoderma can increase the yield of bitter gourd and cucumber by around 20 percent (Cambodia Harvest 2015) and achieve a yield of up to 6 tons per hectare for rice crops (GDA 2014).

Apart from Trichoderma, other BCA types, improved seeds and organic fertilisers were also presented by Angkor Green Company and the EcoAgri Center. They are alternative products for pest control and soil structure that align with organic farming practices.  BCA must be made available for farmers to be able to respond to an ever increasing demand. This is most likely to come about by providing an appropriate regulatory environment and technical support to small-and- medium sized enterprises (SME) that engage in providing these products.

Through the training course, participants were enabled to transfer their knowledge to partners and promote the use of BCA, thanks to SNV’s CHAIN project. Meanwhile, the Eco-Agri Center will continue working with farmers on matters of quality control, transport and market linkages to ensure that the produce is sold to the Khmer Organic Cooperative (KOC) in Phnom Penh through contract farming schemes.