Response of rice genotypes to water stress imposed at the tillering and boot stages of growth

In a pot experiment, free proline accumulated in an appreciable amount under water stress conditions, the accumulation being more in stress tolerant rice genotype (Kachani) than in susceptiable one (IR-28). Relief from stress resulted in rapid disappearance of the accumulated proline. Water stress at tillering induced maximum reduction in panicle number, but the yield and grain sterility were more adversely affected by the stress at boot stage.