Modeling seasonal branch carbon dynamics in pistachio as a function of crop load

A simplified model for the prediction of carbon balance was developed to elucidate seasonal trend sink-source relationships in bearing and non-bearing pistachio (Pistacia vera L.) branches. Seasonal changes growth rate vegetative (leaf shoot) reproductive (infructescence) organs were monitored branches mature rainfed trees during entire growing season (April–September). Simulations from used gain understanding implications crop load on branch (C) depletion alternate bearing. Results showed that energetically able sustain up two infructescences (∼28 fruits) having a slightly positive budget (2.6 g C) at end season. with 4 (∼56 ended very negative (-14.1 suggesting implication resource mobilization heavy load. The simulations allowed identification critical periods pistachio, both characterized by decreasing budget. first is beginning season, leaf out until 35/40 days after full bloom (DAFB), when leaves are still not source carbon, energetic need largely satisfied remobilization reserves accumulated previous year stored through winter. second period branches, ∼100 DAFB, strong reduction area due early senescence drop coincides high request kernel growth. Overall, results demonstrate valid tool study dynamics tree species can help develop physiologically-based management strategies achieving increased more constant productions orchard systems.