Effect of Biological Fertilizers on Seed Oil, Yield and Yield Components of Safflower (Carthamus tinctorius L.) at Different Irrigation Levels

In order to investigate the effects of Azotobacter and mycorrhizal fungi on oil، yield and yield component of safflower (Carthamus tinctorius L.) in different irrigation، a factorial experiment was conducted based on randomized complete block design with three replications، Irrigation at four levels (Field capacity at 20%، 40%، 60% and 100%) and biologic fertilizers at four levels included Non-inoculated (control)، inoculated with mycorrhizal fungi and Azotobacter، inoculated with mycorrhizal fungi and inoculation with Azotobacter. The experiment carried out in greenhouse of Mohaghegh Ardabili University، Agicultural Faculty. Results showed that with reduction irrigation levels، head diameter، number of seeds per head، number of heads per plant، chlorophyll، seed weight and seed yield were reduced. Azotobacter and mycorrhizal fungi at all levels of irrigation have positive effects on chlorophyll، seed yield and yield components and oil percentage and greatly reduced the negative effect of drought stress. The combined application of Azotobacter and mycorrhizal fungi have the highest grain yield per plant، number of heads per plant and number of seeds per head. Biological treatments increased the number of heads per plant، number of seeds per head and seed weight at all levels of drought stress. According to our results it can be stated that in water shortages condition، application of Azotobacter and mycorrhizal fungi greatly improved the growth and seed yield of safflower.