Agronomy Division - Bg 251 and Bg 314- Drought tolerant varieties for rainfed rice cultivation of Dry and Intermediate zones
Due to the erratic rainfall pattern, drought has become the major abiotic stress in rainfed rice cultivation in the dry and intermediate zones of Sri Lanka. Around 35% of rainfed rice farmers abundant their cultivation during the Yala season compared to the Maha, mostly due to insufficient water availability. This reduction in the cultivated extent and crop loss threatens national rice production and food security of the country. Introducing rice varieties, adaptable to water limited situations together with the water saving techniques is an essential requirement in rainfed rice cultivation to mitigate drought stress.
Screening of rice lines for moisture stressed conditions was started since 2008. Drought tolerant rice lines received from the International Rice Drought Tolerant Nursery -2007 (IRDTN) through the program of INGER and “Green Super Rice” project were screened with local recommended varieties under both moisture stressed and irrigated conditions to identify the lines which could perform well under each condition. Promising lines were multiplied and purified from 2010 onwards.
Screening of rice lines
The two promising lines of Bg 10-9028 and IRDTN 07-11 were nominated to National Coordinated Rice Variety Testing programme (NCRVT) for the adaptability testing in 2012 and 2014, respectively. These lines were then submitted to the National Varietal Release Committee (VRC) while the line Bg 10-9028 was released as Bg 251 GSR in 2014 and IRDTN 07-11 was released as Bg 314 in 2020 for rainfed cultivation of Dry & Intermediate zones.
Age : 95 -100 days ( 3 month variety)
Research managed irrigated : 5.1 t/ha
Rainfed stressed: 2.4 t/ha
Maximum Yield Rainfed
WZ :5.6 t/ha -Dahamana (Ratnapura -Balangoda)
IZ : 3.97 t/ha -Narammala (Kurunegala)
Maximum yield Irrigated
Farmer field : 8.06 t/ha -Siyabalanduwa
Research managed : 6.19 t/ha -RRS, Murunkan
Bg 251 GSR
Age : 78 – 82 days (2 ½ months variety)
Grain Type : White Long medium (Nadu)
Irrigated condition : 5.5 t/ha
Rainfed condition: 3.57t/ha
Highest yield recorded
8.34 t/ha (Murunkan)