Comparative Effect of Root Pruning and Pythium irregulare on Water Use Efficiency of Wheat Under Water Stress

A pot experiment was conducted in a glasshouse to compare the effects of root pruning and Pythium irregulare on water use efficiency (WUE) of wheat under drought conditions. The results showed that Pythium had no effect on transpiration (3.35 l) and grain yield (7.4 g) when compared with controls. The transpiration of root pruned plants was less than in controls between the time of root pruning and the start of the drought treatment. Root pruned plants had significantly higher transpiration than controls during the drought. Root pruning treatment significantly (P < 0.05) decreased total grain weight, grain number, WUE and harvest index. The extra water available in the root pruned pots at the end of experiment was not enough to bring the grain yield and WUE up to controls. Root pruning possibly did more than just restrict the ability to uptake all water. This experiment showed the importance of the stage at which root damage occurs and how it affects total WUE.