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Early blight caused mainly by Alternaria solaniSoraeur and Alternaria alternata(Fr.) Keissl is one of the main diseases of potato. To improve forecasting of disease risk and to provide useful tools for a good decision support system, knowledge about the influence of environmental conditions on the Alternariaspecies, is necessary. The pattern distribution of the Alternariaspores during eight potato growing cycles in “A Limia” (north-west Spain), and the relationships between Alternarialevels and meteorological parameters were analyzed. Also, the phenology of the potato plants and the meteorological conditions during the study were monitored. Higher Alternariapeaks were found during plant senescence. Nevertheless, extremely high levels can appear starting the plant flowering, when the disease is more destructive. Statistical analysis showed a close relationship between temperature and relative humidity with the concentration of Alternariain the air. Higher Alternarialevels were observed with a mean temperature above 20 °C and a mean relative humidity below 70%. It is also important to highlight that lower temperature and higher relative humidity during the night, favours the formation of Alternariaspores during the day. The present study showed how differences in weather can be related with the presence of Alternariaspores in the atmosphere of potato crop, and how climate change could affect the development of this agricultural crop. If Spain continues to experience increases in temperature events, longer duration and increasing intensity of early blight epidemics in potato crops are expected in future years.

Potato is one of the main agricultural crops in north-western Spain. Varieties such as Baraka, Kennebec, Desireeand Alavaare more commonly planted, but there is an interest in introducing other improved cultivars. The first step in the identification of a new potato varieties includes an assessment of the morphological characteristics of its aerial parts and their tubers characteristics. In this work, 36 botanical descriptors of 28 potato varieties were studied. The study took place during 2014 and 2015 in an experimental field at the Agricultural Research Centre of INORDE in A Limia (Ourense), Spain. Each variety was planted in three plots distributed within the experimental field. Morphological characteristics were measured on six plants of each variety. Multivariate statistical analyses were performed to identify differences and similarities between varieties. The floral characteristics and the degree of flowering were important features to differentiate the varieties. Also, plant habit, pigmentation in stem, calix and pedicel contributed to this differentiation. La papa es uno de los principales cultivos agrícolas en el noroeste de España. Variedades como Baraka, Kennebec, Desiree y Alava, son las que más comúnmente se siembran, pero existe interés en la introducción de otras variedades mejoradas. El primer paso en la identificación de nuevas variedades incluye una evaluación de las características morfológicas de la parte aérea y del tubérculo. En este trabajo se estudiaron 36 descriptores botánicos de 28 variedades de papa. El estudio tuvo lugar durante el 2014 y 2015 en un campo experimental en el Centro de Investigación Agrícola de INORDE en A Limia (Ourense), España. Se sembró cada variedad en tres lotes distribuidos dentro del área experimental. Se midieron las características morfológicas en seis plantas de cada variedad. Se corrieron análisis estadísticos multivariados para identificar diferencias y similitudes entre variedades. Las características florales y el grado de floración fueron importantes para diferenciarlas. También, el hábito de la planta, la pigmentación del tallo, cáliz y pedicelo, contribuyeron para esta diferenciación.