THE USE OF PGR AND FERTILISER ON THE 'ROCHA' PEAR TO INCREASE THE PRODUCTIVITY

Plant growth regulators have an important role in plant physiology, vegetative development and fruit set. The aim of this work was to evaluate the agronomic efficacy of the isolated use and the combined use of different concentrations of the biostimulant Stimulate^® and the fertilizers Sett^® and Hold^® at fruit set, production and pear quality on ‘Rocha’ pear tree on edaphoclimatic conditions at southern Brazil. The experiment was conducted in the pear orchard, in the 2012/2013 grow season, at Vacaria, Rio Grande do Sul state, on seven-year-old trees of ‘Rocha’ pears grafted on ‘BA 29’ rootstock. The experimental design used was randomized blocks, with three blocks. The biostimulant (Stimulate^®) was applied at full bloom (2 ml L^-1) at the moment that around 70 % of the flowers was opened. The fertilizer Sett^® was applied at full bloom (3 ml L^-1) and Hold^® 15 days after full bloom (1 ml L^-1). The application combined of Stimulate^® and Hold^® showed a increase in the fruit set (5.25%) at 60 days after full bloom, value 78.57% more than the untreated (2.94%), increasing 4.49 t ha^-1 (28.44 t ha^-1) compared with the untreated (24.15 t ha^-1). The combined use of Stimulate^® and Sett^® increased the productivity 9.43 t ha^-1 (33.58 t ha^-1) and the use of Stimulate^®, Sett^® and Hold^®, increased around 7.00 t ha^-1 (26.62 t ha^-1) compared with the untreated (24.15 t ha^-1). The biggest number of fruits per tree was shown with the combined use of Stimulate^® and Sett^® (124 fruits) and Stimulate^® and Hold^® (107 fruits) different just of the isolated use of Stimulate^® (61 fruits). The isolated use and/or combined use of these biostimulants, do not have effect directly to the principal physicochemical characteristics of the ‘Rocha’ pear fruits. It can be inferred that the isolated application of Stimulate^®, Sett^® or Hold^®, does not have significant influence on fruit set and productivity on ‘Rocha’ pear and the combined application of Stimulate^® and Hold^® or Stimulate^® , Sett^® , and Hold^® increased the fruit set on ‘Rocha’ pear grafted on ‘BA 29’ rootstock in Vacaria, Rio Grande do Sul state, edaphoclimatic conditions.