ISHS Acta Horticulturae 587: International Symposium on Asian Pears, Commemorating the 100th Anniversary of Nijisseiki Pear
THE EFFECTS OF SPUR PRUNING AND DEFOLIATION IN THE AUTUMN ON THE FLOWER BUD ABORTION OF PEAR TREE CV. NIJISSEIKI IN PELOTAS, RS, BRAZIL |
| Authors: | F.G. Herter, D. Camelatto, R. Trevisan, V. Verissimo, J.P. Gardin |
| Keywords: | Pyrus pyrifolia, Pyrus, bud abortion, carbohydrate |
| Abstract:
An experiment was conduced in the Embrapa Temperate Climate Research Center, with the objective of evaluating the effect of spur pruning and total defoliation in the autumn on pear trees of the cv. Nijisseiki, in the growing season 1999/2000. Fully productive trees of the cv. Nijisseiki on Pyrus calleryana rootstock were subjected to the following treatments: 1) pruning 50% of potential floral spurs on May 22; 2) complete tree defoliation; 3) control. The experimental design was a randomized block with three replicates. In the next spring during blooming the total number of flower buds and the number of buds aborted were counted and the percentage of buds aborting calculated. The control plants showed an average of 74.35% of flower bud abortion, whereas the spur pruned trees showed 54.11% and the completely defoliated 56.38%. Samples of flower buds on spurs collected on June 5, 2000, were analyzed for their sugar contents. The analyzed data were not consistent. Regarding the flower bud abortion, the reduction of numbers of floral spurs may reduce competition among spurs of the tree, which could explain the lower percentages of flower buds aborted as compared to control trees. On the other hand, lower percentages of flower buds aborted on the defoliated trees than on the control trees and this may be related to the earlier and deeper dormancy caused by the defoliation. When the leaves were cut off, leaf fall was beginning. Therefore, the earlier defoliation may induce deeper dormancy of the flower buds that could be less sensitive to temperature fluctuations during the winter. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
