Rooting of "Ayvalik" olive cuttings in different media

The "Ayvalik" olive cultivar, the most grown for high quality olive oil in Turkey, is generally regarded as showing very good rooting ability. However, cuttings sometimes show moderate or even poor rooting performances, a problem likely related to the use of inappropriate rooting media. The aim of this work was to determine the most successful media among those traditionally used and to identify promising alternatives. October cuttings were planted in 25 different media in two consecutive years under mist propagation conditions. Substrates such as peat, perlite, bark, pumice, sand, polystyrene beads, phenolic foam, rockwool and vermiculite were used pure or in mixtures. In the first year the highest rooting percentage (100%) and visual rating scores (5) were obtained with phenolformaldehyde foam. Perlite-vermiculite (1:1 v/v) was associated with a 95% rooting percentage in both years. The highest mean number of roots (10.8), root length (47 mm), root dry (382 mg) and fresh weights (48.3 mg), and number of secondary roots (13) were recorded in the same medium in the second year. Rockwool, peat-polystyrene (2:1 v/v) and sand-perlite (1:2 v/v) also led to more than 90% of cuttings taking root, while pure sand, peat and peat-sand mixtures gave very low (5-28%) rooting percentages. Perlite-vermiculite 1:1 (v/v) and pre-sized rockwool cubes may be appropriate alternatives to traditional sand-perlite mixtures for rooting "Ayvalik" olive cuttings.