Rooting of blueberry minicuttings

Resumen

This research aims to assess the effect of leaf area on rooting of semi-hardwood minicuttings of cultivar Powerblue, collected on January. Four-node segments with 3.2 cm length and 2.17 mm diameter, approximately, were taken from lateral branches of irrigated plants. The treatments were divided according to number of attached leaves: T1 – two entire leaves; T2 – one entire leaf; T3 – two leaves cut in half; T4 – one leaf cut in half. After preparation of the cuttings, their bases were immersed into a growth regulator solution (IBA) at 2,000 mg L-1 for 15 seconds. Subsequently they were put in expanded polystyrene trays (Isopor®) filled with a mix of commercial substrate (Plantmax®) and washed thick sand at 3:1 ratio. The experimental design utilized was a complete randomized block with one cultivar (Powderblue) and four types of minicuttings, with five replications, each replicate consisting of ten minicuttings. On the 90th day the cuttings were assessed for the percentage of the rooted, dead minicuttings with root, number of minicuttings showing only callus (without root), minicuttings without both callus and roots, number of the better-developed roots, length of the betterdeveloped root and buds number. Treatment 3 and 2 showed the highest percent rooting (98% and 96%, respectively) and treatment 1 showed the lowest (72%). Therefore, the use of blueberry minicuttings for propagation allowed higher use of propagative material. Furthermore, minicuttings of Powderblue with two cut leaves permitted in 90 days the formation of up to 98% of rooted minicuttings.