Breaking dormancy of pear tree ‘Hosui‘ with lime sulphur in two systems of conduction

Abstract

The Asian pear tree when planted in areas where the amount of chilling hours is not satisfied, shows problems in the budding and blooming, requiring artificial means for dormancy break. The objective of this work was to test the effect of different concentrations of lime sulphur solution in the bud sprouting evolution in pear trees ‘Hosui’ conducted in vase-shaped and modified central leader. The applications were carried out when the plants were in the phenological stage A1 (swollen bud), and were formed by three concentrations of lime sulphur solution at 32 °Baumé (100, 200 and 300 mL L^-1), plus mineral oil at 60 mL L^-1 and the control where only mineral oil was applied at 60 mL L^-1. The experimental design was completely randomized, in a split-plot scheme in time, with four replications. The experimental unit was composed by one plant, where four branches of one year old in inclined position. The evaluations were carried out during the period of August to November of 2006, counting the number of buds in sprouting beginning, sprouted buds and died buds. The results showed that the three concentrations of lime sulphur solution in combination with mineral oil were not efficient for break the dormancy of pear trees ‘Hosui’ conducted in vase-shaped and modified central leader.