Evaluation of different species of Mycorrhiza in different phosphorous fertilizer levels throuh physiological traits of purple coneflower under water deficit

The present study aims at investigating the effects of irrigation levels (irrigation after 70, 110 and 150mm evaporation from the pan), phosphorous fertilizer levels and different species of Mycorrhiza (nonapplication of mycorrhiza, application of Glomus intraradices, Glomus mossae, Glomus hoei and coapplication of the three species) and different species of Mycorrhiza (nonapplication of mycorrhiza, application of Glomus intraradices, Glomus mossae, Glomus hoei and coapplication of the three species)) on dry matter accumulation and production of the essential oil of purple coneflower, which was conducted by a split plot and based on randomized block designs in 2016. In most studied traits, lowering the irrigation water from an evaporation level of 70 to 110 mm had no significant effect on the studied traits. Although irrigation after 150 mm evaporation from the pan caused a significant decrease in biological activities, but using some of the fertilizer treatments such as 50% phosphor, along with the simultaneous use of mycorrhizal species, or using the G. hoei species without phosphorus fertilizer, all could prevent the deterioration effect resulting from drought. The combined use of phosphorus fertilizer and mycorrhiza at the irrigation level after 70 mm evaporation from the pan had no effect on the studied traits; however, in irrigation levels after 110 and 150 mm evaporation from the pan, most treatments of the combined use of phosphorus fertilizer and mycorrhiza made a significant increase in the traits. Application of mycorrhizal species, especially G. hoei, had a positive effect on studied traits. In this study, the highest and lowest essential oil yield was obtained with 27.4g in the G. intradice treatment at the irrigation level after 150 mm evaporation from the pan. With regard to the economic importance of the essential oil of purple coneflower, despite the fact the accumulation of the dry matter was affected negatively by the drought, planting this type of plant seems to be possible even in severe drought along with the use of mycorrhiza.