The effects of seed treatment with cold plasma (2–7 min), vacuum (7 min), and electromagnetic field (5–15 min) on Echinacea purpurea germination and performance are studied. All treatments induce faster germination but did not change the final germination percentage, except the decrease evoked by vacuum treatment. The plants grown from all groups of treated seeds have larger height, develop more leaves, some treatments increase root weight. The content of vitamin C and phenolic acids in extracts of plant leaves from the treated groups is substantially higher in comparison to the control, so that the amount of cichoric acid per plant increased up to 3.8‐fold, and amount of vitamin C per plant – up to 1.9‐fold. Seed treatments induce large increase in radical scavenging activity (up to 114%) in leaf extracts.

The aim of this study was to estimate the effects of treatment with atmospheric cold plasma (CP) on sunflower (Helianthus annuus) seeds on germination kinetics, content of seed phytohormones, early seedling growth, and photosynthetic activity. Seeds were treated with a scalable dielectric barrier discharge device for different durations. Differences in CP-induced changes in the seed phytohormone content in cases of positive or negative effects on germination and/or seedling growth were detected. The eustress response was related to the increased ratio between gibberellin (GA) and abscisic acid (ABA) contents, and the distress response was related to decreased GA/ABA and increased salicylic acid content.

The aim of this study was to determine the effects of pre-sowing seed treatment with cold plasma (CP) and an electromagnetic field (EMF) on the agricultural performance of two cultivars of common buckwheat (Fagopyrum esculentum Moench)—‘VB Vokiai’ and ‘VB Nojai’. For this, the effects of CP and EMF on seed germination, plant growth in the field, photosynthetic efficiency, biomass production, seed yield, and the amount of secondary metabolites and minerals in the harvested seeds were estimated. Although the percentage of seedlings that emerged under field conditions decreased by 11–20%, seed treatments strongly improved buckwheat growth and yield. Irrespective of differences in the dynamics of changes in the growth and photosynthetic activity between the two cultivars, the weight of seeds collected per plant for both cultivars was significantly higher (up to 70–97%) compared to the control. The biochemical composition of the harvested seeds (Fe, Zn, quercetin content) was also altered by seed treatments. Thus, pre-sowing treatment of buckwheat seeds with CP and EMF substantially stimulated plant growth in the field, increased biomass production, seed yield and nutritional quality. The results obtained strongly support the idea that plant seed treatment with physical stressors has great potential for use in agriculture.

No abstract

The factors of global climate change specifically affect crop and weed performance. Peas (Pisum sativum L.), spring barley (Hordeum vulgare L.), and wild mustard (Sinapis arvensis L.) were exposed to elevated atmospheric CO2 concentration ([CO2]) (1400 or 700 vs. 400 μmol mol−1) and air temperature (25/18 vs. 21/14°C, day/night) to study the single and combined effects on plant growth, photosynthetic performance, and carbohydrate metabolism. Significantly greater stimulation of the photosynthetic rate was determined at the corresponding growth CO2 concentration (Agrowth), and water use efficiency (WUE) and biomass production were detected for crops than for weed exposed to elevated [CO2]. The possibilities to translocate total soluble sugars (TSS) and starch into roots are considerably higher for crop species, especially N2–fixing pea plants compared with wild mustard, while the accumulation of photosynthates in leaves of wild mustard led to higher photosynthetic downregulation and considerably lower stimulation of Agrowth. Moreover, an increase in WUE was completely eliminated at 4°C above ambient air temperature ([25/400]) in wild mustard grown under elevated [CO2], while crops still maintained slightly higher WUE. These findings suggest that investigated crop species, especially pea plants, have higher advantage than weed under rising [CO2], and this benefit is detected to be even higher under elevated [CO2] and temperature.