Summary
- TDRI reports Thai cassava output fell from roughly 30-33 million tonnes before the mosaic disease outbreak to about 23 million tonnes in the 2025/26 season
- Harvested area contracted from around 9 million rai to 7.6 million rai
- A 2022 industry survey put the area affected by cassava mosaic disease at roughly 3 million rai, or 30-33% of harvested area, while an official August 2023 figure cited just 61,300 rai
- Korat mills are running at under 50% of capacity on average (northeastern association, 24 Aug 2026)
- The central proposals are to scale up disease-resistant planting material and build permanent varietal research capability rather than responding outbreak by outbreak
The constraint is not downstream
The Thailand Development Research Institute published its analysis on 18 August 2026. The authors are Research Director Viroj NaRanong, with Wuttipong Tunyut and Picharee Karunayawong.
Their central finding is that Thailand’s cassava sector already has strong processing capacity and established export markets, but is held back by raw material supply. The authors describe a sector where the raw material base, research, pricing mechanisms, regulations and downstream industries are all moving at different speeds.
How to read the competing production figures
Several production numbers are circulating at once, and each refers to a different season, so they conflict less than they appear to.
| Source | Season referred to | Output |
|---|---|---|
| TDRI (18 Aug 2026) | 2025/26 | about 23 million tonnes |
| OAE (3-9 Aug 2026 edition) | Year 2569 (Oct 2025 - Sep 2026) | 24.186 million tonnes |
| Four associations’ survey (Aug 2026) | 2026/27 | 18.757 million tonnes |
The first two describe the same season using different methods at different times. The third is a forecast for the following season, which has not yet been harvested.
OAE adds that year 2569 harvested area was 7.882 million rai at 3,068 kg per rai, down 7.28% and 3.19% respectively against the previous year.
Mosaic disease and the gap between estimates
The analysis draws attention to how far apart the two damage assessments sit. The 2022 industry survey estimated roughly 3 million rai, or 0.48 million hectares, affected. The official report of August 2023 gave 61,300 rai.
A gap of that size matters for budget allocation and for the design of control measures, because the perceived scale of the problem differs enormously.
What it looks like at the mill
On the processing side, the Northeastern Tapioca Trade Association noted in its price table of 24 August 2026 that average utilisation at starch mills in Nakhon Ratchasima was below 50%.
That figure is consistent with TDRI’s observation that processing capacity is not the binding constraint.
Four proposals
- Short term, accelerate the multiplication and distribution of planting material resistant to cassava mosaic disease
- Long term, build permanent varietal development capability instead of responding to each outbreak as an emergency
- Manage cross-border trade through a flexible import mechanism that varies volumes according to domestic harvests, inventories and industrial demand
- Set an integrated strategy linking disease management, research, supply chains and downstream innovation
Buyers who want to understand how root quality feeds through into starch specifications can start with our products page.
Sources:
- TDRI, Markets Exist, Factories Are Ready, but Cassava Roots Are in Short Supply: Thailand’s Cassava Challenges, 18 Aug 2026 - https://tdri.or.th/en/2026/08/protecting-thailands-cassava-edge/
- Office of Agricultural Economics (OAE), weekly production, marketing and domestic price summary, 3-9 Aug 2026 - https://www.opsmoac.go.th/chonburi-warning-files-481591791959
- Northeastern Tapioca Trade Association (NETTA), price table 24 Aug 2026 - https://www.nettathai.org/