## 3 Results and Discussion
### Elements Concentrations in Leaves of Pumpkin  
In the leaves of sprouts grown in Petri dishes from seeds soaked in silver, a significant increase was observed in terms of chlorophyll \(a\) and \(b\) content, of respectively: 54% and 11% compared to the control. In all other cases, a decrease in the pigment's content was observed (Figure 3a). The concentration of carotenoids in the leaves of sprouts grown in the dishes, in the sample treated with AgNC, was significantly higher, by approximately 79%, relative to the control (C). A reduction in the pigment's concentration was observed in samples stimulated with laser light and magnetic field. Leaves from plants grown in pots (Figure 3b) revealed increased chlorophyll \(a\), \(b\) and carotenoid content in all study groups. The highest significant values of chlorophyll \(a\) were recorded for the \(p\) and AgNC samples, which amounted to 42 and 43%, respectively, compared to the control. Moreover, a significant content of chlorophyll \(b\) was found only in trial \(p\), where it was 25% more than in relation to C. Stimulation with laser light and alternating magnetic field significantly influenced the content of carotenoids, with an increase of 66 and 81%, respectively. In another study conducted by [PERSON] et al. [74], the use of green LED light resulted in a decrease in chlorophyll and carotenoid content in lettuce. In a study by [PERSON] et al. [74] conducted on cucumber plants, saline stress caused a reduction in photosynthetic efficiency. The content of chlorophyll depended on the development phase and the method used. Nanotechnology can have a beneficial effect on the increase in photosynthetic pigments concentration in chickpea according to the results reported by [PERSON] and [PERSON] [49]. In a study by [PERSON] et al. [22] it was observed that silver nanoparticles applied in various concentrations caused a decrease in chlorophyll \(a\), \(b\) and carotenoid content in the leaves of barley, relative to the control. According to [PERSON] et al. [75], the content of photosynthetic pigments in the leaves of pumpkin with nano silver (concentration of 50 mL L\({}^{-1}\)) decreased after 22 days, and, after  
Figure 3: Content of photosynthetic pigments in the leaves of pumpkin plants grown from seeds subjected to the respective pre-sowing treatments: (**a**) leaves from dishes, (**b**) leaves from pots. C—control; L—laser light; _p_—magnetic field; AgNC—silver nanocolloid. Different letters a—d—significant differences (_p_\(\leq\) 0.05), the same letters—no differences. Statistical analysis performed separately for Chlorophyll \(a\), \(b\), and carotenoids. 29 days, there were more of them than in the control group. The increase was 5% (Chl a and Carotenoids) and 10% (Chl b). In our study, at the same concentration of Ag nanoparticles for pumpkin leaves after 8 (Petrry dishes) and 14 days ( pots), the concentrations of chlorophyll \(a\) (43-54%), chlorophyll \(b\) (11-19%), and carotenoids (25-79%) compared to the control. In other studies on rapeseed oil produced from seeds treated with nanoparticles, regardless of the harvest year or the methods used, the content of chlorophylls and carotenoids was significantly higher than the control samples chlorophyll content in plants was also analysed by [PERSON] [76]. Based on the obtained results, he concluded that silver nanoparticles in _B. campestris_ significantly reduced the total chlorophyll content relative to the control when applied in the concentrations of 500 \(\mathrm{\SIUnitSymbolMicro L}^{-1}\) and 1000 \(\mathrm{\SIUnitSymbolMicro L}^{-1}\). Moreover, negative effects were also observed at the dose of 1000 \(\mathrm{\SIUnitSymbolMicro L}^{-1}\) Ag nanoparticles applied in _V. radiata_ and _B. campestris_ with regard to total chlorophyll content compared to the control. In a study conducted by [PERSON] et al. [12], the researchers reported increased chlorophyll content in soya plants grown from seeds stimulated with He-Ne laser light and alternating magnetic fields. As observed by [PERSON] et al.