Effect of Root Pruning on Root Efficiency, Water Use and Yield of Winter Wheat*

Abstract

A pot experiment was conducted to study the effects of root pruning on root efficiency,yield and water use efficiency(WUE) of winter wheat.The results showed that root pruning reduced root weight and root respiration rate,but not affected root/shoot ratio of winter wheat.Under well-watered and moderate drought stresses,the wheat with root pruned had significantly higher photosynthetic rate and root efficiency compared with the control.Under severe drought stress,the pruned wheat had significantly lower photosynthetic rates,but would not significantly affect root efficiency.Under well-watered condition,the lightly pruned roots had no significant effect on grain yield,but the heavily pruned roots would significantly reduce wheat yield.Under moderate drought stress condition,the wheat with the lightly pruned roots had significantly higher yield(25.18 g pot-1),but the heavily pruned wheat had significantly lower yield(18.34 g pot-1) compared with the control(22.31 g pot-1).Under severe drought stress,both root pruning treatments significantly reduced the grain yield of wheat.Under well-watered and moderate drought stresses,lightly pruned wheat had significantly higher WUE(1.57 g kg-1 and 1.85 g kg-1,respectively) compared with the control(1.46 g kg-1 and 1.55 g kg-1,respectively).However,the heavily pruned roots had no significant effect on WUE of wheat.Under severe drought stress,both root pruning treatments had no significant effect on WUE of wheat.It is obvious that suitable root pruning would be beneficial to improving crop production under well-watered and moderate drought stresses.Fig 1,Tab 3,Ref 15