ISHS Acta Horticulturae 470: II International Symposium on Pistachios and Almonds
DRY MATTER ACCUMULATION AND CARBOHYDRATE CONTENT WITHIN BRANCHES OF FRUITING AND DEBLOSSOMED PISTACHIO (PISTACIA VERA L.) TREES |
| Authors: | F.P. Marra, E. Barone, A. Motisi, M. Sidari, T. Caruso |
| Keywords: | Pistacia vera, partitioning, alternate bearing, carbohydrate |
| Abstract:
The aim of this study, as part of a research project on alternate bearing in pistachio, was to determine the effects of fruiting on the within-branch sink hierarchy and seasonal carbohydrate availability in adult trees. In the year prior to the study, two thirds of the trees used in the study were prevented from fruiting by debudding inflorescences. In the year of the study, half of these previously debudded trees were again debudded. These manipulations resulted in three treatments: a non-bearing “off-year” control, an previously debudded fruiting treatment, and a treatment in which trees were non-bearing for two consecutive years. Tree growth was then monitored from early spring until harvest by measuring stems, leaves, fruit and flower buds and analyzing carbohydrate content. Dry matter accumulation differed significantly depending upon crop load in the current and previous years. Differences were observed in dry matter and carbohydrate accumulation and in vegetative growth. Fruits were the major sink for assimilates. Very early competition effects between growing pericarp and inflorescence buds were evident. A higher inflorescence bud dry weight was observed in the twice-deblossomed trees and in the non-bearing control trees. Dry matter accumulation in the leaves of deblossomed non-bearing trees was more than twice that in the bearing ones. These result suggest that the nutritional status of the trees is largely responsible for the alternate-bearing phenomenon. | |
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