Root Colonization, Yield and Yield Components of milk thistle (Silybum marianum) Affected by Mycorhizal Fungi and Phosphorus Fertilizer

In this research the effects of phosphorus (P) ×mycorrhiza interaction on root colonization percent (RCP)، leaf chlorophyll index، yield components and grain yield of milk thistle (Silybum marianum) were studied. Three levels of mycorrhiza (control، inoculation with Glomus mosseae and inoculation with Glomus intraradices) with three levels of P (60، 90 and 120 P kg. ha-1) were evaluated as a factorial experiment based on randomized complete blocks design with three replications at Bu-Ali Sina University. The results indicated that traits of capitula number/plant، seed number/m2، seed weight، grain yield، RCP، P use efficiency (PUE) and P agronomic efficiency (PAE) were affected significantly by P fertilizer، mycorrhiza and their interaction. But، the effect of experimental treatments on seed number/capitula was not significant. The highest and the lowest values for yield components (except seed weight) and grain yield were achieved at treatments of 60 P kg. ha-1 and inoculation with G. mosseae and 60 P kg. ha-1 and non-inoculation، respectively. In comparison with 60 P kg. ha-1 and non inoculation، treatment of 60 P kg. ha-1 and inoculation with G. mosseae increased grain yield up to 58%. The maximum values of RCP، PUE and PAE، in averaging 68. 3% and 19. 7 and 13. 9 g seed/g fertilizer consumption، respectively، were revealed at 60 P kg. ha-1 and inoculation with G. mosseae treatment. Furthermore، with increasing of P fertilizer from 60 to 120 kg. ha-1، these traits decreased. In general، our findings showed that Glomus mosseae species could improve growth properties، milk thistle yield and PUE while reduced P fertilizer consumption on the average of 50%.