BENGALURU, 9 December 2025: String Bio, a technology company developing sustainable, low-carbon innovations for global agriculture, has completed its first field trial in Vietnam in partnership with the Cuu Long Delta Rice Research Institute (CLRRI). The study was conducted in the Mekong Delta during the Summer–Autumn 2025 season.
The trial evaluated CleanRise®, String Bio’s patented foliar microbial biostimulant designed to enhance nutrient-use efficiency, improve tillering, and reduce grain sterility. Previous studies in India have shown that CleanRise can reduce methane and nitrous oxide emissions by up to 50 per cent, while being compatible with cultivation methods such as Alternate Wetting and Drying (AWD), Transplanted Rice (TPR), Direct-Seeded Rice (DSR), and Single Drainage systems.
CLRRI researchers tested CleanRise under four treatment conditions involving two nitrogen levels—100 per cent and 75 per cent of the standard recommended dose—with and without the product. The trial recorded a 12 per cent increase in grain yield compared with farmers’ traditional practices. The use of CleanRise with 25 per cent lower nitrogen application produced yields similar to full nitrogen use, indicating improved nitrogen-use efficiency. Greenhouse gas emissions were reduced by 30 to 40 per cent based on in-field measurements, while grain quality improved, with reduced sterility and better grain fullness.
Dr. Thach and Dr. Cuong of CLRRI said CleanRise is compatible with existing cultivation methods and supports Vietnam’s “One Million Hectare Low-Carbon Rice Program”. Its ease of application and infrastructure-free adoption, they added, make it suitable for scaling across diverse rice-growing landscapes.
Dr. Ezhil Subbian, CEO of String Bio, said the validation from CLRRI builds on consistent results observed in India. “Studies carried out by Dr. Cuong’s lab in the Mekong Delta give us confidence in taking CleanRise, a first-of-its-kind solution, to Vietnam’s rice farmers,” she said.
CLRRI Director General, Dr. Tran Ngoc Thach, recommended further multi-season and multi-location trials to strengthen evidence on CleanRise’s performance.
String Bio is expanding collaborations to support the deployment of CleanRise in Vietnam, aligned with national climate-resilience goals and smallholder livelihood improvement efforts.
