The effects of different concentrations of carbon dioxide and irrigation regimes on quantitative and qualitative characteristics of lentil (variety Bileh-savar)

In order to investigate the effect of increasing carbon dioxide concentration on growth and yield of lentil (Lens culinaris, Bileh-Savar), an experiment was conducted at Ferdowsi University’s research greenhouse. The effects of increasing carbon dioxide concentration from 400 to 800 and 1200 ppm at four irrigation levels (1.25 FC, FC, 0.75 FC and 0.5 FC) under randomized complete design were studied. Elevated amounts of C 2 concentration from 400 to 800 and 1200 ppm, increased yield by 21 and 50%, respectively which may be attributed to corresponding increase in weight of 100 seeds for 13 and 43% and also increased number of pod; 4% and 7, respectively. Also, by doubling CO2 concentration, crop height, shoot dry matter and root dry matter were increased by 15, 28 and 22%, respectively; while tripling CO2, raised these parameters, 24, 59 and 39% respectively. On the other hand doubling and tripling the amount of carbon dioxide concentration, led to a decreaseinevapotranspiration for amount of 12 and 30% .Moreover, the protein content of the grain showed an average decrease of 10 %. It should be mentioned thatreducing the amount of irrigation water reduced the biomass and the amount of protein as well.