# Effect of Magnetic and Electrical Fields on Yield, Shelf Life and Quality of Fruits
## 3 Conclusions  
The objective of this paper was to review scientific results and summarise the emerging field of the effects of magnetic and electrical fields on the growth, yield, ripening, and shelf life of fruits and fruit quality, as well as the potential application of MF and EF in  
Figure 2: Magnetic and electric field affecting the morphophysiological properties of fruit, with possible mechanisms.  
agricultural production. The results varied depending on the plant system, namely on the pre-treatment of seedlings, seed germination, plant growth, development and ripening, and the different categories of magnetic and electrical field intensity and exposure time applied to plants [49, 105, 145, 147].  
Alternating magnetic fields (AMF) with a value of 0.1-200 mT were the most commonly used with 50 Hz or 60 Hz power frequency for the treatment of seedlings, plants, fruits, and irrigated water. This magnetic field mainly caused the following effects on plant growth regardless of the treatment method: increase in speed of germination, plant height, shoot and root weight, and dry weight of the plant. It has contributed to improving fruit growth parameters, number of plant leaves, leaf area, number of flowers/plant, number of fruits/plant, fruit yield, average fruit weight, and the N, K, Ca, Mg, Fe, Mn, and Zn in foliage. These matters also influenced the shelf life of the fruit and its quality, mainly through an increase in firmness, ripening rate, beta caroten and lycopene, sugar concentration, fructose content, and a decrease in acidity and respiration rate.  
High-voltage electrical fields (HVEF) with values of 2-3.61 kV/cm were the most commonly used treatments of fruits. Electrical fields were used to extend the shelf life and improve the quality of the fruit mainly through: a decrease in respiration rate and ethylene generation, and extension of post-harvest life. This is also related to delaying the decline in firmness, as well as the transformation in colour, entire soluble sugar, and also tittatable acidity of fruit and an increase in the content of reduced glutathione, ascorbic acid, and polyphenols. The action of enzymes of SOD, APX, and CAT was suggestively higher than that of the control when in storage.  
The use of electric and magnetic fields is a potential method to increase crops, improve crop quality, prevent disease and pest damage, and inhibit fruit aging. Exposing plants and fruits to an electric and magnetic field is an economic, safe, and environmentally friendly method. Despite numerous attempts, there are still difficulties in applying magnetic and electric fields in field and greenhouse conditions. Further experimentation is needed to develop magnetic- and electric-field-generating devices suitable for use in field and greenhouse crops. Moreover, the inconsistencies of the research results suggest that the effects of magnetic and electric fields on plants and fruit are species-specific and depend on the field strength and exposure time. This has promising research potential for the coming years. The application of electric and magnetic fields in field and greenhouse conditions also causes difficulties. This is another topic for further research.  
Conceptualisation, C.P. and B.S.; formal analysis, C.P.; investigation, B.S. and G.Z.; resources, C.P.; data curation, C.P. and E.S.; writing--original draft preparation, C.P. and B.S.; writing--review and editing, A.S. and E.S.; visualisation, B.S. and M.B.; supervision, B.S., G.Z. and M.B.; project administration, B.S. and A.S.; funding acquisition, C.P. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Minister of Science and Higher Education in the range of the program entitled \"Regional Initiative of Excellence\" for the years 2019-2022, Project No. 026/RID/2018/19, amount of funding 9 542 500,00 PL.  
Not applicable.  
The authors declare no conflict of interest.