13 May 2026, New Delhi: Every year, farmers around the world lose 20-40% of their crops to pests and diseases. Behind each lost harvest is a family that goes hungry, an income that disappears, and a market that falters.

On International Day of Plant Health, the CGIAR Sustainable Farming Program (SFP) reflects on the science, tools, and partnerships that are turning the tide against a growing plant-health crisis, and what must still be done.

Emerging and re-emerging pests and diseases are increasingly threatening agricultural production worldwide. Epidemics in staple crops, invasive pests, and toxin-producing fungi are becoming more frequent, more severe, and harder to manage, driven by agricultural intensification, a rapidly changing climate, and expanding global trade.

The consequences fall hardest on the Global South, where surveillance, diagnostics, and rapid-response systems are often limited. Losses directly threaten food and feed availability, farmer incomes, nutrition, biodiversity, and economic stability.

Recent years have seen major outbreaks of fall armyworm, desert locust, maize lethal necrosis, cassava brown streak disease, banana bunchy top virus, banana Fusarium wilt Tropical Race 4, wheat stem rust, rice yellowing syndrome, potato purple top, soybean rust, forage leaf rust, smut of Napier grass, and cassava witches' broom disease. Invisible yet frequent threats, such as aflatoxin contamination, compound these visible losses, undermining food safety, human and livestock health, and trade.

Climate change amplifies every risk. Shifting temperatures and rainfall patterns alter pest and pathogen distributions, intensify vector activity, and create conditions that favor disease emergence. Greater movement of people, planting materials, agricultural commodities, and conflict-driven human migration accelerates the transboundary spread of threats, creating a global biosecurity challenge that cuts across crops, ecosystems, and the boundaries between human, animal, and plant health.

The CGIAR Sustainable Farming Program (SFP) addresses these threats through farmer-focused, science-driven, innovation-led approaches that strengthen plant biosecurity and agricultural resilience. The program integrates advanced technologies, including metagenomics, remote sensing, artificial intelligence, predictive analytics, and digital advisory systems, with deep field expertise to improve preparedness and response to climate and pest- and disease-related shocks.

Timely information saves crops. A key SFP priority is building integrated early warning systems that provide accurate, actionable predictions of farm-level impacts from temperature, water stress, pest outbreaks, and disease spread. Using satellite imagery, remote sensing, and AI-powered analytics, these systems enable early detection and identification of emerging threats, better forecasting, and timely advisory services to farmers, extension agents, and policymakers.

Two innovations developed by IITA and KALRO illustrate this approach:

• Aflatoxin Early Warning System: Using geospatial AI, this tool forecasts pre-harvest aflatoxin contamination risk zones across maize supply chains. By integrating machine learning with satellite climate data and historical contamination records, the system provides real-time maps that guide spatial targeting of management interventions - empowering policymakers and the grain industry to protect public health and secure agricultural trade.
• Soybean Rust Early Warning Dashboard: Soybean rust can cause up to 80% yield loss and is spreading into new areas as shifting wind patterns accelerate spore movement. This publicly accessible tool generates predicted severity maps for seven countries in Eastern and Southern Africa, combining earth observation data with disease scouting reports submitted by farmers and field agents via smartphone. Extension agencies can use the dashboard to target rust management practices in real time.

Digital agriculture is rapidly becoming a frontline defense against plant health threats. SMART CROP solutions, developed by ICRISAT and partners, deploy satellite imaging, remote sensing, and AI/machine learning for real-time crop stress monitoring and climate forecasting. With more than 4,800 pigeon pea and chickpea-growing farmers digitally onboarded in Telangana and Karnataka, India, these tools enable live monitoring of farm-level pest and disease risk, prescriptive advisories, and farmer soil health cards - transforming data into decisions.

Elsewhere in the program, a novel Electrochemical Lateral-Flow Assay with Linked Analytics (ELLA) approach, developed by IITA and Imperial College London, has been piloted for in-field detection of cassava brown streak virus in Tanzania - bringing rapid diagnostics out of the laboratory and directly to farmers. CIMMYT's satellite-based static and dynamic crop distribution maps in Ethiopia are also improving surveillance and forecasting for wheat stem rust spread.

IFPRI developed an automated real-time media analysis powered by a large language model (LLM) to extract detailed information from news articles on five key pests and diseases. It includes an interactive crop disease dashboard that provides real-time insights and strengthens crop health monitoring. Simulation models for rice leaf blast, bacterial blight, and neck blast were augmented using EPIRICE from IRRI, which AfricaRice also used to predict rice blast disease occurrence in Côte d'Ivoire and Uganda.

No single tool or technology can protect plants alone. CGIAR Plant Health, anchored in SFP, integrates with Genebanks and Breeding-for-Tomorrow programs to identify resistance sources and develop resilient crop varieties. Germplasm Health Units safeguard germplasm biosecurity and prevent the transboundary spread of diseases. Clean seed system innovations ensure disease-free planting materials reach farmers growing vegetatively propagated crops such as cassava, potato, and banana.

A powerful example of integrated partnership is the Consortium for Red Palm Weevil Control, led by International Center for Agricultural Research in the Dry Areas (ICARDA) with International Institute of Tropical Agriculture (IITA) and International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), International Center for Insect Physiology and Ecology (icipe) and International Center for Biosaline Agriculture (ICBA), and supported by the United Arab Emirates and Gates Foundation. This initiative applies biological control, biotechnology, digital tools, and integrated pest management (IPM) to tackle one of the world's most destructive invasive palm pest, while strengthening regional biosecurity systems.

The following examples illustrate how SFP researchers and partners are responding to specific threats across crops, regions, and scales.

Cassava witches' broom disease (CWBD) attacks the vascular system, causing stunted growth, excessive shoot proliferation, poor root development, and vascular necrosis that renders planting stakes unusable. As CWBD is emerging in Southeast Asia and the Americas, over the last five years, Alliance research has transformed understanding of CWBD through metagenomics and bioinformatics - accelerating diagnostics and delivering solutions for farmers. Testing of planting materials ensures that disease-free varieties are rapidly multiplied and distributed, including as a pre-emptive measure in currently disease-free regions.

Rice yellowing syndrome (RYS), associated with co-infection by Rice grassy stunt virus and Rice ragged stunt virus transmitted by the brown planthopper, has emerged as a serious threat to Philippine rice production. IRRI and national partners are strengthening diagnostics, surveillance, and integrated management - with awareness campaigns and technical training building local preparedness and rapid-response capacity. Findings are published in Plant Disease (2026).

In the Andean region, a new 'purple top' disease complex involving psyllid insects and bacterial pathogens threatens potato and tomato systems. The Guatemalan potato tuber moth continues spreading southward. CIP, the Andean Community of Nations, and phytosanitary agencies are jointly developing a regional management strategy, implementing pest risk assessment tools, and running awareness campaigns, diagnostics training, and eco-friendly management programmes.

Across Central, West, North, and East Asia and East Africa, virulent wheat stem rust races, parasitic weeds, faba bean gall disease, and viral epidemics are causing major production losses. ICARDA monitoring shows highly dominant rust races capable of attacking widely grown cultivars. Integrated management packages - combining surveillance, resistant varieties, IPM, farmer training, and regional coordination - are being scaled in partnership with national programs.

ICRISAT has established Fusarium wilt screening facilities in Kiboko, Kenya, and a dry root rot phenotyping facility in Hyderabad, India, to accelerate host-pathogen research in chickpea and pigeonpea. These sick-plot facilities speed up identification of resistant donors and disease-resistant varieties, strengthening national partner capacity across Asia and Africa.

Global banana production faces severe pressure from banana bunchy top disease (BBTD) and Fusarium wilt Tropical Race 4 (TR4), both of which have rapidly expanded, causing major production losses. Alliance of Bioversity International-CIAT and IITA are leading integrated management efforts, developing resistant cultivars through conventional breeding and biotechnology, and deploying digital tools for diagnosis and surveillance. The ongoing spread of BBTD and TR4 poses a significant phytosanitary risk to global banana production and related value chains. In addition, intensification of banana thrips in southwestern Uganda have increased in recent years, causing significant fruit peel damage, lowering bunch quality, and reducing both marketability and farm-gate prices. Alliance bioversity and icipe are working to identify the thrip species involved, and implement IPM for thrips control.