•Long periods of wetness and high temperatures favoured the Alternaria levels.•AUDPC and r-AUDPC showed differences in susceptibility to disease between cultivars.•LO and FB were the most resistant cultivars to the presence of Alternaria.•Epidemiological, aerobiological data and DSS improve the predictions of early blight. Potato crops are susceptible to numerous field diseases causing significant losses in the quality and tuber yield. Control measures have a negative impact in soil and water resources affecting also farmers’ health and food security. Hence, a more sustainable agriculture management is a need to preserve ecosystems. Therefore, the objective of this study was to evaluate the response of nine potato cultivars (Fleur Bleue, Frisia, Fontane, Louisa, Agria, Daifla, Red Pontiac, Kennebec and Desiree) against early blight using a Decision Support Systems (DSS) in a potato-producing area from Northwest Spain. The experimental design was established using control plots and sprayed plots with fungicide according to a disease risk model adapted to the geographical region (DSS plots). Disease rating and severity were evaluated in field from the appearance of the first symptoms to final of senescence and the area under disease progress curve (AUDPC and r-AUDPC) was calculated. Aerobiological monitoring of main Alternaria species responsible potato early blight (Alternaria solani and Alternaria alternata) and the most vulnerable phenological stages were also considered. The susceptibility of the potato cultivars was analyzed based on the weather, severity of the disease and tuber yields. Specifically, temperature and leaf wetness were the meteorological variables that most influenced on the concentration of Alternaria. Conidia accounted for the previous week was the variable that most influenced in development of symptoms measured by AUDPC in natural conditions. Yields in the cultivars of DSS plots were higher than in control plots. Therefore, alternative pest management strategies, and specifically, Decision Support Systems for pest assessment are crucial for sustainable potato production. In this sense, the integration of particular information on disease resistance of commercial cultivars, phenological development of plant, or fungal particles surrounding the crop atmosphere could support these systems for better adjustment without compromising tuber yield and environment.