The growing world's population is constantly in need of food production, and agriculture plays a key role in this produc

Microbial endophytes are considered as one of the most important soil microorganisms which increase their yield per unit area by generating genetic, physiological, and ecological changes in their host plants. We conducted an experiment as factorial in a completely randomized manner with three replications at the Ghasre Shirin greenhouse of Kermanshah province in order to evaluate the interaction of Piriformospora indica (inoculation–noninoculation) with manure (25% of the flowerpot volume—without using manure as a control) and NPK chemical fertilizer (10 g per flowerpot—without the use of fertilizer as a control), the quantitative and qualitative yield and absorption of elements in sunflower. The results showed that the interaction of P. indica, manure, and chemical fertilizer on the colonization percentage, seed oil percentage, nitrogen concentration, phosphorus concentration, and the 1000‐seed weight was significant at 1% probability level, and on yield index, growth, plant height, and concentration of potassium element it was at 5% probability level. Bilateral effects of P. indica with chemical fertilizer and the manure treated with chemical fertilizer on the budding time were significant at the probability level of 1% and 5%, respectively. It seems that the coexistence between sunflower root and P. indica increases the growth of the root system of the plant; thereby it increases the height of plant because of the absorption of essential elements such as nitrogen, phosphorus, and potassium by the root, and increases the quantitative and qualitative yield of sunflower.