## 1 Introduction
ATP is a molecule used to supply energy to other parts of the plant for the accumulation of substances necessary for growth and development such as enzymes, sugars, amino acids, and starch in the reverse reaction: ATP -> ADP + P + energy [14; 15]. Chlorophyll fluorescence contributes significantly to the understanding and monitoring of plant photosynthetic activity. It is a useful tool in scientific research, allowing one to assess the efficiency of photosynthesis, identify environmental stress, analyze the impact of environmental factors on plants, and monitor the overall health of plants. In addition, chlorophyll fluorescence has great potential for predicting the dry matter yield and starch content in plants by analyzing changes in the chlorophyll fluorescence intensity. There are several methods that can be used for this purpose:  
* To measure the fluorescence of chlorophyll, a spectrofluorometer can be used, which allows one to analyze the fluorescence of chlorophyll in plant leaves. Analyzing changes in the chlorophyll fluorescence intensity enables the evaluation of photosynthesis status and overall plant efficiency [8; 21; 22];
* Fluorometric measurements at the cellular level: There are also techniques such as single cell fluorescence imaging that allow for a more accurate analysis of chlorophyll fluorescence at the level of individual plant cells. These methods can provide more detailed information on the efficiency of photosynthesis and starch accumulation in different areas of the plant [23; 24];The assessment of fluorescence during plant development: Regular measurements of chlorophyll fluorescence at various stages of plant development can provide information on the rate of growth and accumulation of dry matter or starch [20];
* Chlorophyll fluorescence measurements yield valuable insights into how stress affects the functionality of a plant's photosynthetic apparatus. Recent research has resulted in the intensive development of chlorophyll photoluminescence measurement methods and the miniaturization of measuring devices. Fluorimeters are integrated with gas exchange measurement devices, allowing for a comprehensive, non-invasive assessment of the photosynthesis intensity. The use of chlorophyll fluorescence measurement techniques is becoming more and more common, starting from the study of single cells of plant tissues, and ending with the imaging of the photoluminescence of agricultural fields using satellite images [24]. A comparison of the measurement results between different plant cultivars or different growing conditions can help identify factors affecting the dry matter and starch yields [19; 20]. Correlations with yield data, and in particular, a comparison of the chlorophyll fluorescence data with the dry matter yield and starch content data, can establish a relationship between chlorophyll fluorescence and yield. Long-term studies and statistical analysis may help to develop prognostic models based on chlorophyll fluorescence, which will predict the crop and its chemical components [20]. An innovative aspect was introduced in this study with a focus on the non-invasive potential for enhancing crop yield and improving its quality. The study aimed to evaluate the impact of the EM Farma Plus microbiological preparation on the crop and the selected chemical components of various potato cultivars representing all categories of earliness. Additionally, the study aimed to assess the potential influence of EM on enhancing the physiological indicators and consequently, the quality of potatoes suitable for both direct consumption and food processing. The current literature highlights the importance of biopreparations based on EM as a versatile tool in agriculture, environmental protection, food industry, pharmaceuticals, and medicine [1; 2; 3; 4; 6; 7; 8; 9; 10; 13; 23; 24], and the potential of chlorophyll fluorescence as a tool for monitoring and optimizing plant production [14; 15; 16; 20; 21].