Yield and water use efficiency of determinant vs multi-tillering wheat lines under contrasting soil water regimes

Abstract

Abstract : Determinant-tillering and multi-tillering spring wheat (Triticum aestivum L.) lines were compared for water use efficiency, yield and yield components under contrasting soil water regimes under greenhouse conditions. The multi-tillering (M) lines produced a significantly higher number of both fertile and infertile tillers than the determinant-tillering (D) lines. The effect of excessive tiller production was reflected in the water use efficiency (defined as grain per unit of water use) of the M lines. On average, they used 24.5% more water per g of grain under well watered conditions and 45.6% more under drought conditions than the D lines. Grain yield did not differ significantly between the two tillering groups under well watered conditions. Under drought conditions, the D lines exhibited a significant yield advantage over the M lines. Total dry matter production was significantly higher for the M lines while number of kernels per spikelct, kernel weight and harvest index were higher for the D lines in both water regimes.