CO2 Responses of Winter Wheat, Barley and Oat Cultivars under Optimum and Limited Irrigation

Abstract

Field crop production must adapt to the challenges generated by the negative consequences of climate change. Yield loss caused by abiotic stresses could be counterbalanced by increasing atmospheric CO2 concentration, but C3 plant species and varieties have significantly different reactions to CO2. To examine the responses of wheat, barley and oat varieties to CO2 enrichment in combination with simulated drought, a model experiment was conducted under controlled environmental conditions. The plants were grown in climate-controlled greenhouse chambers under ambient and enriched (700 ppm and 1000 ppm) CO2 concentrations. Water shortage was induced by discontinuing the irrigation at BBCH stages 21 and 55. Positive CO2 responses were determined in barley, but the CO2-sink ability was low in oats. Reactions of winter wheat to enriched CO2 concentration varied greatly in terms of the yield parameters (spike number and grain yield). The water uptake of all wheat cultivars decreased significantly; however at the same time, water-use efficiency improved under 1000 ppm CO2. Mv Ikva was not susceptible to CO2 fertilization, while no consequent CO2 reactions were observed for Mv Nádor and Mv Nemere. Positive CO2 responses were determined in Mv Kolompos.