Dual-purpose ability of barley and wheat at drought and heat stress conditions

Abstract
Dual-purpose barley and wheat production is a valuable resource to fill feed gaps and grain production, but availability at drought and heat stress conditions is still not clearly studied. Two experiments were conducted at semi-controlled green house to determine biomass production at vegetative stages, chlorophyll content and grain yield. Experiment 1 consists of four clipping treatments on wheat, i.e. one, two, three times clipping and un-clipping control. Experiment 2 combined two clipping treatments (one clipping and un-clipping) and two levels of water (low: 40 % of field capacity; normal: 85 % of field capacity) on barley. Wheat grain yield was severely affected by increasing clipping number under heat stress. Total biomass at one clipping was the same level as control treatment. Although physiological maturity was delayed 8 days from control to 3 times clipping application, biomass and yield remained below the control application due to shrinkage in plant height and other organs size. Clipping and water levels at barley significantly impacted biomass and plant height, but all traits were not related by interactions clipping x water level. The clipping application in heat stress reduced total biomass by 21.3 and 30.4 % in well-watered and dry conditions, respectively. Contrary to what is expected, it seems clear to obtain satisfactory forage and grain yield by optimizing the management technique, growing in dual-purpose production in wheat and barley in warm environments.