Variation in Tree Size, Yield, Cropping Efficiency, and Alternate Bearing Among ‘Kerman’ Pistachio Trees
in Journal of the American Society for Horticultural ScienceAbstract
The pistachio (Pistacia vera L.) industry in California is based largely on a single pistillate (i.e., nut-producing) cultivar (Kerman) supported by seedling rootstocks of P. atlantica Desf. Data were collected and analyzed for tree growth and productivity of 113 mature ‘Kerman’ trees/P. atlantica seedlings over two cycles of alternate bearing. Tree size as estimated by trunk cross-sectional area varied 4-fold among the trees analyzed; tree yields, averaged over 4 years, varied 8-fold within the plot, and cropping efficiency (yield/cm2 of trunk cross-sectional area) varied 3-fold among the trees within the orchard. The severity of alternate bearing also was calculated. Eight superior trees were identified within the orchard that not only had higher average yields and cropping efficiencies, but also exhibited much more regular cropping patterns (i.e., reduced severity of alternate bearing) than adjacent trees and the orchard as a whole.
Contributor Notes
Received for publication 17 Oct. 1986. We thank E. Surber, Blackwell Land Company, Bakersfield, Calif., who collected a portion of the data and disclosed them for analysis and publication. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.
