GROWTH EVALUATION OF BLUEBERRY MINICUTTINGS UNDER DIFFERENT GROWTH REGULATORS

The work aimed to evaluate the growth of blueberry minicuttings ‘O’Neal’ using benzylaminopurine (BAP) and gibberellins (GA₃). A completely random experimental design was used in a 3×5 factorial arrangement, three treatment (control, 250 mg/L of BAP, 250 mg/L of BAP + 250 mg/L of GA₃) and five evaluations (0, 30, 60, 90 and 120 days). Biweekly applications were done during this period. The experiment was carried out in greenhouse and after 60 days plants were transferred to a low tunnel. Minicuttings height, number of leaves, number and mean length of lateral shoots were measured. There was interaction between treatment and time for the number of leaves. There were differences between the 60 and 90 days, and the latter and 120 day, for minicutting height for all treatments. The same occurred for the number and mean length of shoots. Control treatment and the use of 250 mg/L BAP + 250 mg/L GA₃ responded in the same way regarding mean length of shoots, being superior to the use of 250 mg/L of BAP. In the control treatment and the use of 250 mg/L of BAP + 250 mg/L of GA₃ the number of leaves linearly increased depending on evaluation period. Using 250 mg/L of BAP the number of leaves decreased from 0 up to 60 days. Then, from the 60 to the 120 days, the leaves increased. The phytoregulators BAP + GA₃ show similar behavior to the control treatment regarding mean length of shoot and number of leaves. The growth in height and shoot number of the blueberry minicuttings ‘O’Neal’ increases by time and are independent of the use of phytoregulator.