Mitigating Tropical Cyclone Susceptibility in Pecan (Carya Illinoinensis) Orchards

Abstract

The production of tree nuts such as almonds, walnuts, pistachios, and pecans is a globally important agricultural industry. Climate risk posed to tree nut orchards was recently brought to light by a series of severe tropical cyclone impacts to the primary pecan-producing areas of Georgia, USA which caused $1.2 billion USD in losses. Understanding how severe wind risk changes with pecan tree size can guide the development of climate-smart practices that improve global resilience of tree nuts. Immediately after 2023 Hurricane Idalia, we reconstructed orchard damage for 1142 trees in 11 orchards across southern Georgia and examined how tree susceptibility varied with wind speed and tree size. We found that the probability of tropical cyclone damage to pecan trees increased with wind speed and was highest for intermediate size classes—peaking at 35 cm diameter at breast height. We developed a conceptual model for assessing hurricane risk on crop yield which illustrates how explicit consideration of age-structure can influence expected profits when hurricane risk is considered. We recommend that pecan growers consider age and size structure in orchard planning, use mechanical hedge pruning, and use irrigation practices that promote deep root development to increase windfirmness. Climate-smart practices can enhance resilience and sustainability in pecan orchards in future climates where increases in severe tropical cyclones are expected.

Keywords: hurricane, tropical cyclone, wind damage, canopy pruning, tree mortality, climate-smart, climate mitigation