Influence of tiller heterogeneity on yield components of rice grown under different nitrogen regimes

Abstract

<span class="fontstyle0">Increase in rice yield under excessive nitrogen (N) supply is negligible, hence it is necessary<br />to analyze the limiting factors via yield components. The present study was carried out during<br />2014 and 2015 growing seasons in order to quantify the yield componenents of different types<br />of tiller at various N levels. Tillers were divided into three different types (superior, medium<br />and inferior) based on their productivity. The results indicated that the quantitative proportions<br />and yield contributions were decreased in superior tillers, increased in the inferior tillers, while<br />remained stable in the medium tillers with increasing supply of N fertilizer. The increased rate<br />of spikelets per panicle in the superior tillers was higher under all N application levels; however,<br />a high quantitative proportion and the lower number of spikelets per panicle of the inferior<br />tillers might have resulted in the reduced population of spikelets per panicle. The rates of grain<br />filling percentage and grain weight in medium and inferior tillers were decreased with<br />increasing N applications, which led to a decrease in population grain filling and grain weight.<br />The present study suggested that the enhancement of grain filling and weight of the inferior<br />tillers would be an effective approach to further improve the per acre yields of rice. The<br />acquisition of more accurate yield component data, in the perspective of tiller, might be helpful<br />for researches regarding the development of augmented rice breeding architectures.</span>