In 2014 and 2015, two separate studies were done in order to investigate the effect of mulching and deficit irrigation on the reproductive traits, fruit yield, and water-use efficiency of 15-year-old cv. Konservolia olive trees in the field conditions. These factorial experiments were conducted in the Randomized Complete Block Design and had three replications. The deficit irrigation factor of the experiments (100% full irrigation (control) and 75 and 50% deficit irrigation) was performed in drip system and the second factor, mulching, was performed in three levels (polyethylene, organic materials (straw), and no-mulch). The results showed that there was a significant difference between the different irrigation and mulch treatments due to the measured characteristics. In both of the experiments, the highest fruit weight, pulp fresh and dry weight, and fruit yield per tree and hectare was obtained from the treatment with 100% irrigation and mulching. Decreasing the amount of irrigation water reduces the above-mentioned traits while, in comparison with the no-mulch treatment, applying mulches can increase these traits. Therefore, by utilizing straw and polyethylene mulches, deficit irrigation can be applied on trees without causing any damages on them and as a result, saves the amount of irrigation water in the olive orchards.
