# Effect of Magnetic and Electrical Fields on Yield, Shelf Life and Quality of Fruits
## 2 Effect of Magnetic Fields and Electrical Fields on the Growth, Development, and Yield of Fruit
### Effect on Germination  
Many studies show that a magnetic field has a positive effect on seed [27; 40; 41]. The strength of the MF and exposure time are among the most significant factors influencing seed germination, emergence rate, and seed yield [62]. There were significant interaction effects of strength of magnetic field and the duration of exposure on germination percentage [59]. The highest value was noted when seeds were treated with a strength of 0.1 Tesla for 15 min. By contrast, the lowest germination percentage was at an exposure of 0.2 Tesla for 15 min. Similar results were obtained by [PERSON] et al. (1999) with an exposure time of 10 min [63]. Magnetic treatment can accelerate plant emergence by 2-3 days, compared with control plants [63]. [PERSON] et al. (2011) and [PERSON] (2012) showed that the MF dose and the duration of exposure can affect the germination traits of different seeds, including tomato and broad bean. They demonstrated that the strength of MF plays a significant role in germination percentage [59; 64]. [PERSON] et al. (2013) observed a germination that was approximately 11.0% stronger in magnetically exposed seeds than in unexposed seeds, although the seedlings emerging from the SMF treatments did not show a constant increase in biomass accumulation [41]. They confirm that longer seed exposure (24 h) resulted in better germination, and that shorter exposure (1 and 2 h) resulted in faster germination [40]. The germination rate is an indicator of the metabolic advance of germination events in the treated seeds. In magnetoprimed seeds, the germination rate was 30.3% higher than in unprimed seeds [45]. The results of [PERSON] et al. (2018) show that 0.2 mT MF induced parental tomato seeds to yield F1 seeds that have a higher percentage germination rate and dry weight than control tomato parental seeds. A magnetic field of 0.2 mT was applied for 7 min 48 s. [47]. Scientists report that exposure of tomato seeds to magnetic fields may lead to a significant improvement in the growth and development of plants produced by them [41]. This improvement induced by the magnetic treatment was also consistent with the results of other studies [65] that also report enhanced root and stem growth and fresh weight in tomato plants. [PERSON] et al. (1999) also reported a positive effect of magnetic treatment on leaf thickness in crop tomatoes, leading to a noticeable increase in the thickness of the spongy tissue, and in the length and width of chlorophyll-containing cells and the upper and lower epidermal cells [66]. Research has reported that magnetic treatment of tomato seeds resulted in a significant increase in leaf area, leaf dry weight, average weight of \begin{table}
\begin{tabular}{c c c c c} \hline
**Variety** & **Method** & **MF Parameter** & **Effect** & **References** \\ \hline  & & MF & & \\  & & for 50 Hz & Increase in seed germination, & \\ Tomato & Treatment of & 20, 40 and 60 mT & growth of young plant, size of & \\ _Pavlina_ & seeds and plants & for 20 min & fruit, stem length, weight of & [58] \\  & & seeds and plants for & tomatoes and earlier fruit setting & \\  & Seed treatment with & 48 days & & \\ Tomato & distilled water & & MF & Optimal magnetic treatment 0.1 T & \\ _Castlerock_ & and irrigation with & 0.1; 0.15 and 0.2 T & for 15 min, increase in stem length & \\  & magnetised water & for 1, 5, 10 and 15 min & Leaf area and fresh and dry weight & \\  & Seeds & MF 4–6 mT & & \\ Tomato & Seeded plots, & for 2.5 s—seeds & Yield increased on _Monza_ 28–51\% & [PERSON] et al., 1994 \\ _Rocco_ and _Monza_ & Irrigation with & 3 times -seedbeds & and bloomed 3–4 days earlier & [60] \\  & magnetised water & 3 movement—plots & & \\  & & MF & & \\ Tomato & Seed treatment & 10 mT for 10 min & Increase in height, yield and fresh & [PERSON] et al., \\ _Castlerock_ & Irrigation with & Magnetic field & weight, P mineral content in & 2012 \\  & magnetised water & treatment of & plant leaves & [61] \\  & & water 80 mT & & \\ \hline \end{tabular}
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