Valutazione dei modelli di gestione del rischio grandine nella produzione di mele

Alpine fruit farms usually insure their production (passive defense) against hail damage and rarely use anti-hail nets (active defense). To explain the choice between two alternatives for hail risk management in the case of the production of apples, we developed a model that simulates the effects of changes in the costs per hectare with and without public aids. The cost per hectare of insurance (passive defense) increases linearly with the rate of risk hail, ceteris paribus. The cost per hectare of anti hail nets (active defense) is always independent of the rate of risk. We can therefore detennine the level of tisk hail that leads to the break even point (BEF). To the left of the BEP is the preferred passive defense, active defense on the right. The model was then validated in three areas with different levels of risk hail. Results obtained allow evaluating how the level of hail risk influences the choice between insurance and anti-hail nets in the case of apple production. In alpine areas analyzed, the public aid moves the BEP to the right and then change the choice in favor of passive defense, perhaps because of the negative externalities (effects on the rural landscape) generated by the anti-hail nets. Since the public aid per hectare increases linearly with the rate of hail risk, farmers choose the passive defense even when the environmental matrix is almost adverse. There is, therefore, a lot of scope for improving the efficiency of choice, both in public and private sectots.