High nitrogen input causes poor grain filling of spikelets at the panicle base of super hybrid rice

It is generally accepted that poor grain filling of rice plants under high nitrogen (N) input is due to increased competition for assimilates because high N rate usually results in large sink size with more spikelets per panicle. In this study, we examined grain filling parameters of spikelets in different panicle position under various N treatments to determine the effect of N rates on grain filling. A super rice cultivar with large panicle was...