The effect of ecological growing on the potatoes yield and quality

In the years 1995-1997 the effect of ecological growing on the yield and selected parameters of quality of consumer potatoes (in comparison with conventional way) were investigated. The ecological way of growing differed in the lack of chemical protection against diseases and pests and industrial fertilizers. Field trials were realised with seven varieties (Impala, Karin, Agria, Korela, Rosella, Santé and Ornella) on two sites (Uhříněves and Valečov). The ecological way of growing had markedly negative effect on the yield (decrease by 36%). In qualitative parameters the ecological way increased inconclusively polyphenol content (by 10.2%), decreased inconclusively nitrate content (by 11.0%) and reducing sugars (by 22%). It did not affect dry matter content, resistance of tubers to mechanical damage, table value and glycoalkaloid content. Variety Santé achieved the best results from the point of view of the yield and majority of qualitative parameters among varieties. Qualitative parameters of ecologically cultivated potatoes were significantly affected by the year of cultivation.