Effect of Different Deficit Irrigation and Salinity Management on leaf, shoot and root growth of (Mentha piperita L.)

In order to study the effects of deficit and salinity water stresses on aerial and underground organs of Mentha piperita L. two separate experiments were conducted. A randomized complete block design factorial experiment with three replications was designed at 2017-2018 year in a research farm of department of water engineering, campus agriculture and natural resources of Razi University. Water deficit experiment included three levels (100 (Control), 80 and 60% irrigation requirement) and salinity experiment included four levels control (0.9, 2, 3 and 4) dS/m. The results showed that the effect of water deficit stress on aerial characteristics (shoot fresh and dry weight, leaf fresh and dry weight, leaf area and shoot height) and underground organs (root dry weight, root length, root area, volume and density) were significant. The maximum and minimum of leaf dry weight for 100 and 60% of irrigation requirement observed 2.47 and 1.54 grams per plant. With application of 20 and 40% irrigation deficit leaf area in comparison with control 22 and 31% decreased. With application of water irrigation salinity for 2, 3 and 4 dS/m leaf area 15, 20 and 47% decreased. The highest tolerance salinity of Mentha piperita L. was obtained as 3dS/m.