Evaluation of three varieties of Creole potato in yield, resistance and susceptibility to Phytophthora infestans under organic fertilization

Abstract

Potato cultivation is essential for food security as it is a staple food for the population. It is also an important source of income for rural communities by providing jobs and a diverse range of marketing opportunities. Potatoes are affected by Phytophthora infestans, the causal agent of late blight or potato leaf spot disease, which can lead to plant death if adequate agronomic measures are not taken. This research evaluated the response of three varieties of native potato to organic fertilization in terms of yield, resistance, and susceptibility to the pathogen. The study was conducted in the municipality of Facatativá, Cundinamarca, where varieties 1 (Violeta), 2 (Sua-Pa), and 3 (Colombia) were planted, each with 10 replicates under a completely randomized design (CRD). Morphological and yield variables, as well as percentages of disease severity based on severity values ​​from the International Potato Center (CIP), were recorded. A Tukey means comparison test was performed with an alpha of 0.05 for yield, and regression analysis was performed for disease severity and yield. The area under the disease progress curve (AUCPE) was determined, resulting in Variety 3 with an area of ​​398, followed by Variety 2 with 269, and Variety 1 with 259; therefore, Violeta was the most resistant variety to the disease under the conditions evaluated. In terms of yield, Variety 3 was statistically significantly higher, with a greater number and weight of tubers. Using linear regression, Variety 1 had the lowest AUCPE relative to P. infestans at 40.23%; however, its yield was the lowest. Despite being the most susceptible to potato blight, Variety 3 had the highest yield; these results may indicate the penalty imposed by the varieties for the yield or resistance traits.