Effects of potassium fertilisation on potato late blight and yield ‒ Short communication

Abstract

Potato yields and infestation by P. infestans are related to the supply of potassium. Potassium was applied as soil fertilisation combined with split foliar applications or only as split foliar treatments at a maximum dose of 150 kg/ha K2 O in both strategies, Lord and Ditta cultivars were used. Additionally, water spraying was included as an alternative treatment in order to maintain uniform moisture in the rows of plants. Plants fertilised with foliar spraying only were more infested than plants fertilised with combined methods. The fertiliser increased the protection impact of copper treatments against P. infestans. This may suggest a possible synergistic effect in reducing the symptoms of the disease, however not always statistically significant in both cultivars. Plants sprayed with water but without soil application of fertiliser showed a statistically significantly higher infestation rate, both in Lord and Ditta cultivars, compared to plants with soil application of fertiliser but without watering.