Starch is the main component of potato and it accounts for about 17 ÷ 21 % of the weight of fresh tubers. In addition to quantity, the structure and composition and consequently the physical-chemical properties of that biopolymer are important factors to determine the direction of its use in food and industrial applications. In turn, those indicators are impacted, in addition to the genotype, by environmental conditions and agricultural practices used during plant cultivation. For the proper progress of physical and biochemical processes in a plant, it is fundamental to comprehensively provide it with easily available nutrients. A comprehensive feeding of the potato plants translates directly into the quantity and quality of starch contained in tubers.The application of appropriate fertilization (type and amount of the fertilizer applied including methods of dosing mineral components and organic matter) affects among others the granulation of polymer grains, the content of amylose and phosphorus, thermal properties and starch gelatinization process; for example the content of starch in tubers decreases with an insufficient potassium supply and with too high doses of nitrogen. The phosphorus fertilization has a smaller effect on that parameter. When applied to soil, phosphorus and potassium fertilizers promote the formation of large starch grains, while the nitrogen fertilization has an adverse effect. The fertilizing of potato plants does not affect the crystallographic structure of starch, however its relative crystallinity increases with the increasing dose of K and it decreases with the increasing supply of nitrogen fertilizer. By determining the impact of plant fertilization on starch properties, there are provided useful and important information for the potato producers, the researchers and the industrial sector, because in this way it is possible to control the conditions for growing potatoes, which have an effect on producing a native starch with specific physical-chemical properties.
potato, starch, fertilization, nitrogen, phosphorus, potassium