How to maximize yields of some hybrid rice varieties

PhilRice (Philippine Rice Research Institute) researchers have determined that the public hybrid rice variety Mestizo 1 performs better under saturated soil condition (just enough water to keep the soil moist) than under continuously flooded condition during the dry season.

The researchers led by Evelyn F. Javier, a senior science research specialist, found that efficient management of irrigation water for the public hybrid rice varieties could spell higher yields.

They observed that Mestizo 1 produced higher yield under saturated condition than under continuously flooded condition. They attributed the higher yield to more spikelets, longer panicles, and heavier seeds.

However, the researchers observed just the opposite on the two other public rice hybrid varieties — Mestizo 2 and Mestizo 3. These varieties produced higher yields when grown under continuously flooded or submerged condition during the dry season.

During the rainy season, however, Javier and her co-workers noted that the effect of irrigation water becomes irrelevant because of the occurrence of rains.

In another study, Javier and JM Rivera also observed that the parentals of Mestizo 1 attain higher efficiency in the absorption of nitrogen, phosphorus and potassium under saturated soil condition. This means that the parentals produce more grains per kilogram of applied nitrogen, phosphorus and potassium when the soil is under saturated condition.

In contrast, the parentals of Mestizo 3 produced more grains per kilogram of applied nitrogen, phosphorus and potassium in continuously flooded soil. On the other hand, Mestizo 2 parentals did not show any dramatic response to the two water management methods in terms of nitrogen use efficiency.

Overall, the performance of the public hybrids Mestizo 1 and Mestizo 3 follows that of their parentals. – Sosimo Ma. Pablico