Effects of biostimulants on some quality parameters of coloured potato tubers

Abstract

Recently in Lithuania coloured potatoes have attracted the attention of investigators and consumers due to their nutritional value, taste and appearance. These potatoes contain important biologically active compounds, starch, dietary fibre, high quality proteins, vitamins and mineral elements. The yield and quality parameters of potato tubers depend on many factors such as cultivar and growing conditions. Biostimulants are usually applied in addition to standard fertilization treatments to improve the nutrient use efficiency and the crops quality. Therefore, the aim of the study was to determine the effect of biostimulants on some quality parameters of coloured potato tubers. Methods. The field experiment was carried out in Raseiniai district (Lithuania). The experimental plots were arranged in a randomized design with three replicates. The following two factors were examined: I – three coloured potato cultivars: Red Emmalie (medium early with red flesh), Violetta (medium early with dark purple flesh) and Salad Blue (medium early with light purple flesh), II – two types of biostimulants applied: control (without biostimulants); biostimulant Naturvital-Plus (8 l ha-1); biostimulant Naturamint-Root (2 l ha-1). Biostimulants used at a dose recommended by the manufacturer. Apart from using biostimulants, the potatoes were grown according to the traditional potato growing technology. They were planted in the May and harvested in September. The influence of biostimulants on some quality parameters of potato tubers was determined immediately after harvest. Dry matter in the tubers was determined by drying samples at temperature of 105 °C to the constant weight; content of fibre - by the method of Heneberg-Shtoman, content of protein - by Kjeldahl method