String Bio, CLRRI complete field trial of its biostimulant in Vietnam
String Bio, a technology company building sustainable, low-carbon solutions for global agriculture, has completed its first field trials in Vietnam in collaboration with the Cuu Long Delta Rice Research Institute (CLRRI) in the Mekong Delta.
A media statement said that the trial focused on ‘CleanRise’, String Bio’s patented foliar microbial biostimulant, which enhances nutrient-use efficiency and stimulates systemic plant responses to boost productive tillering and reduce grain sterility.
In prior Indian studies, CleanRise has demonstrated reductions of up to 50 per cent in methane and nitrous oxide emissions. It is compatible with a wide range of cultivation systems including AWD (Alternate Wetting and Drying), TPR (Transplanted Rice), DSR (Direct-Seeded Rice), and Single Drainage systems, it said.
Compatible with existing techniques
During the Summer-Autumn 2025 season, the CLRRI team tested CleanRise on paddy fields under four treatment scenarios involving two nitrogen levels (100 per cent and 75 per cent of standard N dose), both with and without CleanRise.
Quoting Thach and Cuong from CLRRI, the statement said: “CleanRise is compatible with existing cultivation techniques and aligns with Vietnam’s national ‘One Million Hectare Low-Carbon Rice Program’. Its ease of use and infrastructure-free adoption position it as a promising tool for scale out across diverse rice farming landscapes in Vietnam.”
Ezhil Subbian, CEO of String Bio, said the validation data from CLRRI extends the consistent performance, scaling and benefits of CleanRise witnessed with rice farmers across India. To have studies completed with Dr Cuong’s lab at CLRRI in the Mekong delta provides a high level of confidence for us to bring CleanRise, a first-of-a-kind solution, to the rice farmers of Vietnam.”
Published on December 2, 2025
