## 4 Discussion  
### Influence of Cultivation Technology on Yield of Dry Matter and Starch and Quality of Chips  
Microbiological preparations are part of or supplementary to innovative potato cultivation technologies aimed mainly at reducing the occurrence of pests and improving the quantity and quality of the crop. They do not act directly to reduce diseases, but through their soil or foliar application, they increase the biological activity of the soil. According to [23; 49; 50], they eliminate or reduce the sources of infections in the soil that reduce the yield of crops. In the technology used in this work, nitrogen-fixing bacteria play a large role in converting indigestible forms of nitrogen into forms available for plants. According to many authors [5; 23], EM significantly contributes to the improvement of soil structure. Muctilage substances released by EM adhere to humus and mineral particles, forming soil lumps, thus improving its structure [10; 23; 28; 51]. Microorganisms also produce bioactive material useful for plants, such as hormones and growth stimulators that trigger cell division [20; 22]. In the conducted research, the EM Farma microbiological preparation used in the form of dressing seed potatoes with an aqueous solution of the EM Farma preparation significantly increased the yield of dry matter and starch but also the quality characteristics of chips produced from the tested potato cultivars. On the one hand, the pre-planting treatments had a positive effect on the quality of the chips by reducing the fat absorption of the chips and reducing their moisture, but on the other hand, they worsened the organoleptic and visual evaluation of this product. This is partly attributable to the increased content of reducing sugars in potato tubers. However, not all reasons for this potato reaction are known, and further research is needed to clarify this issue in depth. EM preparations complement other agrotechnical activities aimed at reducing the occurrence of pests. They do not directly reduce diseases, but by applying them to the soil, they increase the microbiological activity of the soil [52]. According to [PERSON] et al. [17; 18], an important phenomenon occurring after the use of EM is the conversion of putrefractive processes causing the development of diseases and pests, auto-oxidation, and regeneration. Thanks to this, post-harvest residues treated with EM preparations cease to be a source of pathogen development and become food for beneficial microorganisms, which convert them into nutrients that supplement plants. The assessment of the effect of potato cultivars and biodynamic preparations (BD) 500 and 501 on the concentration of phenolic compounds, the quantitative and qualitative composition of anthocyanins and phenolic acids, and the antioxidant activity of colored potato tubers was carried out in Lithuania by [PERSON] et al. [26]. These authors showed that after spraying with the BD 501 preparation, the concentration of total phenolic compounds in tubers of 'Blue Congo' and 'Red Emmalie' cultivars was significantly higher (20.1 and 5.4%); anthocyanins were 59.8 and 10.4% higher, respectively, and the antioxidant activity was about 1.3 times higher in both cultivars than in the control without the use of biodynamic preparations. The use of both preparations (BD500 and BD501) had a significant effect on the accumulation of anthocyanins in 'Blue Congo' and 'Vitelotte' tubers. However, preparation 500 tended to decrease the concentration of antioxidant compounds and antioxidant activity in tubers of all potato cultivars. The cultivar was the dominant factor influencing phenolic antioxidants and the highest concentration of phenolic compounds, anthocyanins, and phenolic acids, as well as the highest antioxidant activity in 'Vitelotte' tubers. Malvidin and petunidin compounds were identified as the main anthocyanins in 'Blue Congo' and 'Vitelotte' tubers, and pelargonidin compounds in Red Emmalie tubers. The dominant phenolic acid was chlorogenic acid.