| The effect of different sources of K and N on graded yields, dry matter, reducing sugars and quality of french fries and crisps, respectively were examined in two maincrop varieties (AGRIA and MARLEN). Fertilizers applied were cattle manure, potassium sulphate (PS), PS + grinded horn, grinded horn (GH) and a control. Results of two-factorial field experiments (2002-2004) on a loamy sand are presented. Cultivar and fertilizer had a significant effect on final yield, combined mineral K and organic N (PSGH) being the most efficient fertilizer with regard to graded yields for crisp (>40 mm) and french fries production (>50 mm). K content of tubers could be increased, but dry matter was lowered by most fertilizers, so that only the unfertilized plots... |
