The effects of nutrient foliar application on the quantity and quality of Sage (Salvia officinalis L.) essential oil in different irrigation levels

A field experiment was carried out as split plot based on the randomized complete blocks design (RCBD) with 12 treatments and three replications at the faculty of Agriculture, University of Maragheh during 2021 growing season. The main factor was three irrigation levels included irrigation after 20% maximum allowable depletion (I20) as control, 40% maximum allowable depletion (I50) as moderate stress and 60% maximum allowable depletion (I80) as severe stress. The sub-factor was foliar application of macro mix gold, ecoquel micromix, vitalem forte and non-application of fertilizer (control).The results demonstrated that the highest (255.4 g/m2) and lowest dry matter yield of sage (190.5 g/m2) was achieved in normal irrigation condition with application of macro mix gold and sever water stress without fertilization. The dry matter yield decreased by 10.1 and 27.8% in moderate and severe drought stress conditions. Also, application of macro mix gold, ecoquel micromix and vitalem forte enhanced the mentioned trait by 25.1, 24.7 and 16.4% in comparison with no fertilization (control), respectively. The highest essential oil content (1.47%) and yield (3.19 g/m2) was observerd in moderate water stress fertilized with macro mix gold. In addition, the maximum content of cis-thujone (40.50%), camphor (17.08%) and 1,8-Cineole (9.98%) was achieved in moderate water stress fertilized with macro mix gold. Based on the obtained results, it can be concluded that the foliar application of macro mix gold could be recommended for improving essential quantity and quality of sage in drought stress conditions.