Effects of Mycorhizal Fungi and Plant Growth Hormones on Potato Tuber Yield and Concentration of Macronutrients

Mycorhizal fungi increase uptake of phosphorus and other mineral nutrients from unavailable sources. Plant hormones promote root production (rhizogenesis) and thus affect plant growth by increasing uptake of nutrients. Thus, the present study aimed to assess the effects of plant hormones and mycorhizal fungi on yield and macronutrient concentrations of potato (Fontane cultivar). For this purpose, a factorial experiment was conducted in the greenhouse using a randomized complete block design and three replications. The experimental factors were types of plant hormones sprayed [without hormone (control), gibberellic acid (GA), indole acetic acid (IAA) and naphthalene acetic acid (NAA)] and soil inoculation with mycorhizal fungi [without inoculation (control) and inoculation with Funneliformis mosseae, Rhizophagus intraradices, and Funneliformis mosseae + Rhizophagus intraradices]. There were significant effects due to soil inoculation by mycorhizal fungi and application of plant hormones on fresh yield, diameter, dry matter content and concentrations of nitrogen, phosphorus and potassium of potato tuber. The highest fresh yield, dry matter content and nitrogen concentration of potato tuber were measured in treatments inoculated by Funneliformis mosseae + Rhizophagus intraradices and sprayed with GA. The highest diameter and potassium concentration of potato tuber were obtained from the treatments inoculated by Funneliformis mosseae and sprayed with GA. The treatments inoculated by Rhizophagus intraradices and sprayed with NAA had the highest concentration of phosphorus in the tuber. Generally, the results of this study indicate that inoculation of soil by mycorhizal fungi and spraying potato plant with growth hormones increase yield and macronutrient concentrations of potato tuber.