The Effects of Potassium Fertilization and Irrigation on the Yield and Health Status of Jerusalem Artichoke (Helianthus tuberosus L.)

The objective of this study was to determine the effects potassium fertilization (applied soil at 150, 250, and 350 kg K2O ha?1) irrigation on yield (fresh matter dry above-ground biomass tubers) health status tubers leaves three Jerusalem artichoke—JA (Helianthus tuberosus L.) cultivars (Topstar, Violette de Rennes, Waldspindel). Topstar cultivar characterized by highest total tuber (60.53 Mg FM (65.74 ha?1). An increase in rate fertilizer ha?1 did not affect yields. greatest yields observed response 150 ha ?1 (64.40 Irrigation increased 59% 42% average. Phytopathological analyses revealed that JA were most frequently colonized fungi genera Alternaria, Fusarium, Epicoccum. Alternaria Fusarium more prevalent non-irrigated than irrigated plots. A higher number fungal pathogens isolated from cv. Rennes grown a plot fertilized with 250 ha?1. Tubers heavily Penicillium, Botrytis, Rhizopus. Fungal species genus all treatments, they less identified Only plots supplied free fungi. cultures pathogenic artichoke had minor negative impact fresh yield.