CONTRIBUTIONS OF SHORT- AND LONG-SHOOTS TO YIELD OF ‘KERMAN’ PISTACHIO

The canopy of a mature pistachio (Pistacia vera L.) tree is composed of two types of shoots: short-shoots composed entirely of preformed units, and long-shoots composed of both preformed and neoformed units.
Since the production of these two types of shoots is known to be related to rootstock and rootstock influences yield of pistachio the relationship of these two types of shoots to yield was investigated during two cropping years.
Short-shoots produced significantly less total yield and had fewer fruit clusters per shoot compared with long-shoots.
Long-shoots positively affected yield components in one year, but had no effect in the other year.
Whether the differences in the one year were due to canopy position and light interception or differences in the carbohydrate allocation within the two types of shoots could not be determined from the current data.
Long-shoots initiated more inflorescence buds, although inflorescence bud formation was restricted to the preformed growth and only the 3-4 earliest neoformed nodes.
However, when expressed as a percentage, long-shoots retained a lower percentage of initiated inflorescence buds, compared with short-shoots.
Regardless of shoot type, less than half of the inflorescence buds that were retained from the previous season produced mature fruit clusters, indicating that inflorescence bud retention from the previous season may not be the primary limiting factor to yield in pistachio.

IX International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems

T.M. Spann, R.H. Beede, T.M. DeJong

Pistacia vera, alternate bearing, yield components, inflorescence bud retention, rootstock effects

https://doi.org/10.17660/ActaHortic.2011.903.136