Effect of mycorrhizal inoculation and phosphorus supply on morphological traits of rosemary under greenhouse conditions

Abstract: Rhizobium inoculation increases nutrients uptake by modification of root characteristics. This experiment was conducted in 2015 at Zabol university research farm (Chah-Nimeh) in a completely randomized design based on factorial arrangement with three replications. The first factor was five levels of phosphate: 100, 75, 50, 25 and 0 (control) kg ha^-1 and the soil inoculation consisted of two arbuscular mycorrhizal: Glomus intraradices and G. mosseae. The measured traits include number of leaves, stem dry weight, root fresh weight, shoot dry weight, stem diameter, root length, plant height, SPAD readings, root and shoot nitrogen content, essential oil percentage and essential oil yield. Results indicated that using of G. intraradices and G. mosseae have no significant effects on rosemary essential oil yield. The highest and lowest essential oil percentage rate of 2.2 and 1.6 %, respectively were as a result of taking ammonium phosphate 100 kg ha^-1 and in the control (no ammonium phosphate). On the other hand, higher shoot (1.17) and root (1.96 ) nitrogen percentage and were recorded followed by interaction between G. mosseae species and the control, respectively. The SPAD readings of rosemary increased significantly by the application of fertilizer in levels. On interaction effects, G. intraradices (M1) and application of 75 kg ha^-1 ammonium phosphate treatments had the best SPAD readings. The results of this study indicated that the inoculation of arbuscular mycorrhizal fungi in soil with optimal fertilizer application greatly improved rosemary growth and nutrient uptake and the effect was greater under greenhouse conditions.