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.

In this study, the effects of seed treatments with different stressors, such as cold plasma (CP), a vacuum and an electromagnetic field (EMF), on the in vitro germination of industrial hemp cv. Futura 75 were compared with the effects on germination in the field, plant growth, and the amount of major cannabinoids in the leaves and inflorescences of female plants. CP and EMF (but not vacuum) treatments improved in vitro seed germination, but had no impact on germination in the field. EMF treatment increased the weight of the above-ground part of male and female plants grown for 4 months by 65–70% and the number of female inflorescences by 70%. CP stimulated the growth of male plants (weight increased 1.4 times) but reduced the growth of female plants. Vacuum treatment did not induce changes in the growth of female and male plants. Vacuum and EMF treatments did not change the amount of cannabidiolic acid (CBDA), but CP decreased the CBDA content in hemp leaves by 41%. Vacuum treatment increased the amount of CBDA in female plant inflorescences by 26%. Thus, hemp seed treatment with EMF has a potential application for increasing the biomass of female plants. CP treatment can be used to increase male plant production while vacuum treatment can stimulate CBD production.

Background. Changing climatic conditions cause changes in tree phenology, which is important for the survival of species and their spread in local ecosystems. This study concentrated on long-term (1957–2016 or 1980–2016) observations of 11 conifer species introduced to Lithuania with the aim to evaluate the response of their bud swelling phenophase to climate warming, considering the hardiness zones of their natural habitats. Materials and Methods. Sequences of the start date of the bud swelling phenophase of 11 introduced conifer species (Abies veitchii, Larix decidua, L. kaempferi, L. laricina, L. × marschlinsii, L. sibirica, L. sukaczewii, Picea mariana, Pinus mugo, Taxus baccata and Thuja occidentalis) were analysed. Data were collected from the paper archives of Kaunas Botanical Garden of Vytautas Magnus University (VMU). Sequences of bud swelling start dates were transformed into sequences of number of days from the beginning of the year. Results. Results indicated an advance of the bud swelling phenophase of ten conifer species introduced to Lithuania (the speed of changes varied from –0.10 to –0.98 days/year in the 1980–2016 period) and a delay of Larix sukaczewii (respectively, +0.12 days/ year) of the bud swelling phenophase, mainly influenced by the March temperature. Conclusions. The connection between the observed conifer species hardiness zone of the natural habitat and the reaction of the bud swelling phenophase to climate warming could be observed only when species from one genus were compared. To confirm this phenomenon, a research on a larger amount of introduced species with wider habitat hardiness zone options is needed in future.