Inter-annual variability of Pinus pinea L. cone productivity in a non-native habitat

Abstract

Pinus pinea produces the most expensive pine nuts worldwide, with a masting habit (variable cone productivity over time) in its native habitat. This study assessed the presence of masting habit in a non-native area, the correlation of annual cone production with climatic variables, and the impact of resource depletion on cone productivity 3 and 4 years after a bumper crop. During 10 years, all cones tree−1 were harvested and counted in three plantations. Cone yield stability was measured via coefficient of variation of cones tree−1. Climatic factors were correlated with stone pine masting. Results indicated that inter-annual variability of cone yield and annual rainfall during 3 years prior to seed maturity, and thermal oscillation 2 years before harvest, were significantly correlated. A correlation was found between cone productivity when reproductive shoot differentiation or when male and female primordia induction occurred, and cone productivity 3 and 4 years later. Individual tree fruit load did not reduce flower induction. The most productive trees will also be the most productive ones in the following years, a finding with practical implications for breeding programs and plant production.