ON POTATO TUBERS YIELD (SOLANUM TUBEROSUM L.) AND INFESTATION OF TUBERS WITH STREPTOMYCES SCABIES AND RHIZOCTONIA SOLANI

Elemental sulphur and Kieserite fertilization have been demonstrated to improve po-tato tuber (Solanum tuberosum) yield quality and resistance against Streptomyces scabies; the bacterial effect was attributed to reduced soil pH. So far, no information has been available about the influence of S, Mg and supply of micronutrients on bacterial and fun-gal diseases of potato plants. Field trials performed in a split-plot design with varied fertili-zation treatments (NPK with/without S and Mg and microelements B, Zn, Mn, Cu fertili-zation) including three potato cultivars were conducted in the south eastern region (near ZamoϾ) of Poland in 2004-2006. The application of S and Mg and micronutrients decre-ased the tuber infection rate and severity of Streptomyces scabies and Rhizoctonia solani, while increasing potato tuber yield. Generally, tuber yield and wholesomeness were mostly related to a genotype (cultivar), mineral fertilization treatments and their interaction with a cultivar