RSSI Has Reached Mindanao: What Farmers Need to Know Now

What Is Being Reported

Ratoon Stunting and Streak Infection (RSSI) first emerged in Negros Oriental in late 2024. It spread fast: infected plants stunt at ratoon stage, yields drop sharply, and there's no chemical cure once the bacteria are in the tissue. The only way to stop it is to remove infected plant material, disinfect tools, and plant clean certified cuttings.

By mid-2026, RSSI had moved beyond Negros. Bukidnon, which is one of the Philippines' largest sugarcane-producing provinces, reported its first cases in Kitaotao municipality in early May 2026. Davao del Sur and Sarangani, two provinces that feed the Davao Sugar Central, followed. Sultan Kudarat, further south, added the southernmost confirmed cases.

These are not isolated sightings. They are separate confirmed outbreaks in distinct mill catchment areas, which means the disease is already distributed across Mindanao's major cane-producing belt.

The Mindanao Numbers

Bukidnon has the largest confirmed footprint so far. The Philippine News Agency reported 415.31 hectares affected across multiple municipalities. Kitaotao is the worst hit at 147 hectares. Valencia City contributed 7.74 hectares and Don Carlos added 5.3 hectares. The first detection in Bukidnon was on May 2 in Kitaotao, which means by the time this article is published, the outbreak has been present for more than three months and has had the full growing season to spread.

Davao del Sur and Sarangani combined reported approximately 800 hectares in the Davao Sugar Central catchment area. Davao Sugar Central is one of the major mills serving southern Mindanao. An 800-hectare combined footprint at this stage of the season, before harvest, points to significant yield losses when those farms deliver in November and December.

Sultan Kudarat confirmed 91 hectares in Columbio municipality. This is the southernmost confirmed RSSI location in the Philippines as of this writing. Columbio is in the Sarangani Bay watershed area, well south of the Bukidnon plateau.

Taken together: over 1,300 hectares of confirmed RSSI in Mindanao across three mill catchment areas. The national picture is more severe, with 92,780 hectares reported and more than 18,000 validated by SRA across all sugarcane-producing regions.

Why Mindanao Is Different From Negros

Negros farmers, particularly in Negros Oriental, have been watching RSSI since it was first confirmed on the island. Many have been dealing with it for over a year. Extension networks, even informal ones through cooperatives and Facebook groups, have been sharing information about symptoms, tool disinfection, and certified seed sources.

Mindanao is earlier in that learning curve. In Bukidnon, Davao, and Sarangani, many farmers are seeing RSSI for the first time this season. Some may not recognize the symptoms. Stunted ratoons can be mistaken for drought stress or nutrient deficiency, which means infected fields can go unaddressed while farmers try to solve a soil problem that isn't there.

The mills serving Mindanao, including BUSCO (Bukidnon Sugar Milling Company), Crystal Sugar Company in Bago City (which sources from both Negros and parts of Visayas), and Davao Sugar Central, are all working with DA and SRA on response protocols. But the infrastructure of certified clean seed production and distribution in Mindanao is still being built up. Negros had over a year to develop that. Mindanao is starting now, three months before milling season.

What the Government Response Looks Like

The Department of Agriculture allocated ₱35 million for RSSI response across affected regions. That covers chemical supplies, drone operation for affected field fumigation, and logistics. The SRA has been coordinating surveillance and validated case counts; their figures (18,000+ validated nationally) are lower than the reported 92,780 because validation requires physical inspection and lab confirmation, which takes time.

At the farm level, the government response currently involves: field surveys by extension workers, certification of clean seed sources, and the propagation of biological control agents (specifically beneficial fungi in the Trichoderma family) that suppress the spread vector. Some provincial governments in Bukidnon have been issuing quarantine protocols modeled on the African Swine Fever containment approach: movement restrictions on plant material between barangays with confirmed cases.

Whether this will be enough before the November milling season opens is unclear. The validation and clean-seed supply chain takes time that may not exist.

What Mindanao Farmers Should Do Now

These are the steps that have reduced spread in Negros farms that caught the disease early.

Check ratoons for stunting symptoms. Infected ratoons are shorter than expected for their stage, with shortened internodes and possible yellowing of lower leaves. If ratoons across multiple plant positions in a field are uniformly shorter than neighboring fields at the same age, that's the pattern to investigate. Individual stunted plants can be stress. Uniform stunting across ratoons is RSSI until proven otherwise.

Disinfect cutting tools between fields and between plant positions in the same field. The bacteria spread on dirty blades. A 10% bleach solution (1 part household bleach to 9 parts water) applied after each cut is sufficient. Some farmers use a flame torch on steel blades. The key is that the tool is clean before it touches the next plant, not just at the start of the day.

Contact your DA agricultural extension officer or the nearest SRA provincial office for Bukidnon, Davao, or SOCCSKSARGEN before replanting. If a field is confirmed infected, replanting from ratoons is how the next crop gets infected before it's even in the ground. Certified clean seed (pre-inspected plant cuttings from disease-free sources) is the only safe option. The provincial SRA offices can connect you with certified seed suppliers.

Do not move plant material between farms without certification. If a neighbor asks to buy or borrow seed cuttings from what looks like a healthy field, that field still needs testing. Visual health is not a reliable indicator.

Log what you're seeing. Whether you use a notebook, a phone photo, or the Sugarcane Farm Manager app, recording the field, the date, the severity, and what you did creates a chain of documentation that helps your cooperative, your mill, and your own management. An unrecorded outbreak is much harder to control than a documented one.

The November Milling Season

Sugarcane milling in Mindanao typically begins in November for the 2026-27 season. Infected plants that haven't been managed by then will deliver to the mill. The direct loss is lower tonnage and lower CCS from stunted cane. The secondary loss is spread from infected harvest equipment, transport trucks, and field residue if farms aren't cleaning up properly post-harvest.

BUSCO and Davao Sugar Central are both implementing pre-harvest field assessments in affected areas. Farmers in those catchments should expect extension officers to visit before the season opens. Being ahead of that with your own field documentation makes the conversation more productive and gives you a paper trail if disputes arise over delivery weights.

Tracking the Spread

The Sugarcane Farm Manager app has a shared outbreak map with two layers: SRA-validated data and farmer-reported sightings. The Negros outbreak data is already in the map. As Mindanao cases accumulate and SRA validates them, those coordinates will be added to the national layer.

If you're a farmer in Bukidnon, Davao del Sur, Sarangani, or Sultan Kudarat and you have a confirmed or suspected case, you can log it directly in the app's Pest tab. It won't appear on the public map until validated, but it creates a local record for your own management and contributes to the aggregate data that helps everyone see where the disease is moving.

The app is free at app.lmreyna.com and works offline. No signup required to start recording.