Commercially, propagation of blueberry by cutting is the very usual method, which gives a range of results according to the cultivar. This research aimed to evaluate the effect of indol-butyric acid (IBA) on rooting of blueberry hardwood cuttings. It was used segments of secondary branches with four buds and mean diameter of 4.5mm. The experimental design was totally randomized in a 5x3 factorial, five concentrations of IBA (0; 1500; 3000; 4500 and 6000mg L-1) and three cultivars (Delite, Bluebelle and Briteblue). It was used four replications and ten cuttings per plot. After cutting, the base of the cuttings was dipped for 10 seconds into a solution of IBA. Then, they were put to root in a mix of thick sand and commercial substrate Turfa Fertil® (1:1) with pH 5.5 and manually irrigated. After 138 days from trial installation, percentage of rooted cuttings, number of root per cutting, length of the largest root, number of shoots, length of the largest shoot and percentage of surviving cuttings were evaluated. According to the results it was not verified interaction among different factors. It was verified difference among cultivars only in the length of the largest root, number of root per cutting and percentage of surviving cuttings. For concentration of IBA, it was verified by regression analysis, a linear behavior for the variables increasing rooted and survived, but the response was quadratic for the longest root length. It was concluded that the concentration up to 6000mg L-1 IBA is not sufficient to express the maximum rooting potential of the blueberry cuttings cultivars Delite, Bluebelle and Briteblue.
Vaccinium ashei; plant growth regulator; vegetative propagation
