Chile: Strong PSA presence in kiwi this season

Chile is grappling with an outbreak of Pseudomonas syringae pv. actinidiae (PSA), a bacterial disease affecting kiwi plants, which was under control from 2011 to 2020. The disease has spread across the Metropolitan and Biobío regions, threatening both green and yellow kiwi varieties, especially the latter due to its higher susceptibility. The recent polar frosts have significantly worsened the outbreak, leading to symptoms like red sap exudation and damage to plants in late winter and early spring. This has resulted in varying levels of damage, from minor to catastrophic, including dead plants and reduced fruit-bearing. The most vulnerable are new kiwi plantations, with the disease also affecting mature plants. To mitigate the damage, a comprehensive phytosanitary program involving regular bactericide application and strengthening of the plant's internal defenses is recommended. The high bacterial load and favorable weather conditions pose a serious threat to kiwi production in Chile.