## 4 Discussion  
The purpose of this study was to observe the effects of pre-sowing buckwheat seed treatment with CP and EMF on different indices of plant agronomic performance in field conditions during cultivation for the entire vegetation period. It has been reported previously [31] that treatment of buckwheat seeds with gliding arc discharge for 3 min increased the number of germinated seeds by 9%; however, this effect was not statistically significant. In addition, inhibitory effects on buckwheat seed germination have been observed with increasing processing time or using other devices for CP treatments [31], and only the very early growth of sprouts has been tested. Figure 7: Secondary metabolite content in harvested seeds of two buckwheat cultivars. (**a**) ‘VB Vokiai’ seeds; (**b**) ‘VB Nojai’ seeds. Rutin content is presented in mg/g, quercetin and D-fagomine amount–in \(\upmu\)g per g. The means \(\pm\) standard errors of three replicates are presented (\(n=3\)). Different lowercase letters indicate significant differences (\(p<0.05\); [PERSON]’s LSD test). We showed that the effects of seed treatments on buckwheat growth persist for the entire vegetation season, and that the effects on biomass production and seed harvest are considerably larger in comparison to the effects on seed germination. We have previously demonstrated that the effects of seed treatments on germination in vitro are different from those in substrate for Norway spruce [33] and sunflower [34; 35], as well as on seedling emergence in the field for industrial hemp [36]. In the case of buckwheat, little to no effect on germination was observed in vitro, while no effect or a moderate negative effect (11-20%) was found on seedling emergence in field conditions. It is possible that some of the seedlings that germinated from treated seeds did not survive 2 weeks after sowing under field conditions. Nevertheless, strong positive effects on plant growth on a longer time scale (14 weeks) were determined (Figure 4). Such findings are similar to the results obtained previously with red clover (_Trifolium pratense_) grown for 5 months in the field [30], when EMF strongly stimulated plant growth although such treatment did not affect germination. Taken together, these results contradict the widespread opinion that the effects on germination can be regarded as an informative estimate for the response of plants to seed treatments. Moreover, such findings demonstrate the importance of longer observations (at least for the entire vegetation season) under conditions used for plant agricultural cultivation. The results obtained show that the effects of seed treatments on various plant growth traits are different in two common buckwheat cultivars, similar to the results obtained for red clover [30]. The dynamics of the induced changes in plants of the two buckwheat cultivars followed different patterns over time: 4 weeks after sowing, a stronger positive effect on morphometric parameters of 'VB Vokiai' cultivar was observed in comparison to that after 8 weeks; meanwhile, the effects on 'VB Nojai' seedlings were much smaller or absent after 4 weeks, but positive effects of CP and EMF on growth (plant weight, the number and weight of stems and generative organs) became apparent after 8 weeks (stronger in comparison to the effects on 'VB Vokiai'). At this time point, seed treatment led to an improvement in the indices of photosynthetic efficiency in leaves of 'VB Nojai', but not 'VB Vokiai' seedlings. This result indicates that stimulation of plant growth by seed treatments is related to the activation of photosynthetic processes, which also confirms the results obtained in sunflowers [35; 36]. Stimulation of the net rate of photosynthesis in seedlings growing from CP treated seeds has been demonstrated directly in wheat [47]. It has been shown that treatment of sunflower seeds with CP and EMF induced substantial changes in leaf proteome, resulting in stimulated expression of proteins involved in photosynthetic processes and their regulation [34].