EFFECT OF ROOTSTOCKS UNDER DIFFERENT CHILLING ACCUMULATION CONDITIONS ON PEAR DORMANCY RELEASE
The aim of this research was to evaluate the effect of increasing chilling hours below 6°C on bud burst of the Packhams Triumph pear grafted on different rootstocks. The experiment was carried out at the Embrapa Clima Temperado Research Station, Pelotas-RS, Brazil (32°41S, 52°24W, 57 m a.s.l.), from autumn to spring of the 2011 season. Potted plants of rootstock quince (Cydonia oblonga) Adams and EMC, and pear (Pyrus calleryana), and the European pear Packhams Triumph were used as scion cultivar. Plants were exposed to 0, 250, 500, and 750 chilling hours below 6°C in a refrigerated chamber and thereafter transferred to a greenhouse kept at 25°C. Bud break was considered when buds reached the green tip stage. Lateral vegetative buds of P. calleryana released from dormancy and sprouted after 500 chilling hours, and reached 100% bud burst after 40 days in greenhouse. No statistical differences were observed between the two quince rootstocks, which reached values of bud break lower than 30%. The highest bud burst values were observed on the upper portion of the shoot. P. calleryana had the lowest chilling requirement as compared to both quince Adams and EMC. However, when Packhams Triumph was grafted, P. calleryana was the most effective as compared to the quince.
Yamamoto, R.R., Louzada, R.S., Mello Farias, P.C., Herter, F.G. and Pereira, J.F.M. (2015). EFFECT OF ROOTSTOCKS UNDER DIFFERENT CHILLING ACCUMULATION CONDITIONS ON PEAR DORMANCY RELEASE. Acta Hortic. 1094, 183-187
Pyrus, grafting, chilling requirement, quince, bud break