Abstract

Late blight, caused by the oomycete Phytophthora infestans (Mont.) de Bary, is considered a re-emerging problem in the potato crop worldwide, due to the variability of the pathogen and the climatic instability that favors its presence and dispersion, with a high incidence and severity. Therefore, farmers use pesticides excessively and inopportunely, increasing environmental impact and risk to users' health. The objective of this work was to implement an early warning system as tools to support decision-making in family farming in Latin America, in order to reduce the losses caused by this disease, in a sustainable and safe way for the user. During the 2018 to 2020 seasons, experimental plots were established in Argentina, Chile, Ecuador and Panama, with varieties of different susceptibility to the disease. The treatments were based on fungicide applications according to the early warning systems, fixed schedule and no fungicide control. Early warning systems validated in each country were used. Control efficacy was assessed by determining foliage damage and tuber yield. The results show a reduction of more than 45% in the number of applications, 53% in the environmental impact and 53% in the reduction of costs of fungicide control. These results show the high impact of the implementation of these support systems for sustainable intensive agriculture.