Tribonema

Tribonema minus is a species of yellow-green filamentous algae that, in the context of rice cultivation, is considered a harmful biological agent. Although biologically categorized as algae, its rapid proliferation in flooded fields interferes with rice development, acting as an invasive pest that compromises crop health.

The primary crop affected by this organism is rice, particularly during the seedling stage. The filamentous structures entangle young rice shoots and roots, preventing them from accessing essential sunlight and oxygen. This biological competition often leads to stunted growth and significant crop thinning in the early season.

Symptoms of infestation are easily identifiable: the appearance of dense, yellowish-green mat-like structures on the water surface and around the submerged parts of the rice plants. In severe cases, these mats float, completely blocking light penetration to the water column and causing the rice seedlings to wither or decay.

Environmental conditions that favor the development of Tribonema minus include high levels of water eutrophication, specifically high nitrogen and phosphorus concentrations. Warm temperatures and stagnant or slowly moving water in the rice paddies provide the optimal habitat for the algae to multiply exponentially within a short period.

The economic damage caused by this algal growth includes reduced plant density and suppressed tillering, which directly translates to lower grain yields. Effective management strategies include:

• Application of selective algicides to curb algal blooms.
• Water level management to prevent shallow, stagnant areas.
• Optimizing fertilizer timing to reduce nutrient runoff into the water.
• Regular monitoring and cleaning of irrigation ditches.