Tackling new invasive pests and diseases

Increased global movement of goods and services coupled with changing climatic conditions has exposed farmers to unexpected challenges of new pests and diseases. This is not only spelling disaster to farmers but it is also posing threat to food security.

The menace has globalized to alarming proportions afflicting at least 41 percent of food crops worldwide. In some areas post-harvest losses attributed to pests and diseases have ranged from 70 to 100 percent.

In Kenya some of the singled out devastating plant diseases includes Maize Lethal Necrosis, tomato blight disease which afflicts tomatoes, beans and potatoes, the deadly Ug99 strain of stem rust known for causing massive wheat losses and Downy mildew which strikes vegetables.
In the recent past, farmers have witnessed emergence of new species of aphids which are very destructive to food crops. Farmers are also grappling with Tuta absoluta caterpillars, commonly known as leaf miner, which until 1968 were confined to South Africa but have now spread to most parts of the world.

One way to address the challenge is proper diagnosis of the pests and diseases. An in depth analysis to establish the exact disease or pest that has afflicted a plant should always be undertaken before advising on proper management and preventive procedures. Wrong diagnostics and application of agrochemicals have led to pestilence resistance.

It is always advisable for farmers to implement preventive measures rather than curative when dealing with invasive plant pests and diseases. Early detection of pests and diseases before they spread has always proved effective. Conventional methods such as crop rotation, punctual weeding and removal of weeds of infested or damaged material have remained impactful and cost-effective to date. Most farmers rush to agro-vets to buy agrochemicals that are not necessarily effective for their problems. Agrochemicals should only be used when right diagnosis has been performed.

Quarantine implementation between borders is another effective management of new disease strains and pests. Quarantine safeguards introduction, establishment and spread of harmful plant pests and diseases. If quarantine has been properly enforced, devastating diseases in Kenya such as banana wilt, Tropical Race 4 and others in areas where they were not known to occur, would have been possible.

Kenya Plant Health Inspectorate Service (Kephis) is in charge of implementation of Sanitary and Phytosanitary measures. They have been at the forefront of protecting Kenya’s plant health through the regulation of imports of plants and plant materials, phytosanitary inspection and certification, and provision of diagnostic services to support plant health and seed certification.
Kephis has increased awareness of the importance of keeping plants healthy to achieve the UN 2030 Agenda, especially Sustainable Development Goal 2 – zero hunger, the need to adhere to international standards and measures for plant health to minimise the risk of spreading plant pests through trade and travel, improving monitoring and early warning systems to detect pests invasion in advance for timely mitigation and sustainable use of pest control products to keep plants healthy while protecting the environment.

To address the adverse impacts of climate change on plant health and biodiversity, Kephis advocates the adoption of climate-smart solutions in crop production and resource utilisation.
Proper pests and disease management will not only make smallholder farmers more food secure, but also result in improved crop-based household incomes.