Grain quality of rainfed rice (Oryza sativa) genotypes in Central Queensland, Australia

Water is a major cost (20-30%) for Australian rice production as the industry water use is very high (12.3ML/ha) due to flood irrigation. Developing appropriate rainfed rice varieties provide alternatives for the rice industry to maintain growth while the cost for water is increasing and availability is decreasing. However, maintaining high grain quality from rainfed production systems may pose challenges. Thirteen dryland rice genotypes (7 long 6 medium grain lines) were tested during the summer rainy season in Alton Downs, QLD under rainfed and strategic irrigation management in the 2013/14 season. Measured grain quality parameters only differ due to varieties but not due to water management practice (rainfed vs strategic irrigation). Four of the medium grain varieties (Lasix XB, Inaminka XD, Linklaer A1 and Laski VII) produced grain yield of 4 – 5 t/ha with strategic irrigation but were compromised with low amylose and grain protein. The gel temperature was generally higher for long grain and lower for medium grain type varieties. The millout percentage however was not linked to grain type nor to irrigation method, and all tested varieties recorded millout in excess of 50%. All tested medium grain types were earlier for maturity compared to long grain type. Therefore, the planting time for the long grain type may need to be adjusted to maintain their yield and quality. Yield and detailed grain quality analysis from crop grown in wider agro-ecological zones with full growing seasons will be presented from crops planted in the 2014/2015 season.