Swailing affects seed germination of plants of European bio-and agricenosis in a different way

Abstract

Swailing as a part of agricultural practice is an illegal habit in many European countries. The indirect effect of swailing is the emission of volatiles (SGV), hence the aim of the study was to identify their impact to seeds of different species occurring or grown Europe. It was carried out on seeds of 29 species of 10 botanical families within the angiosperms. The response to SGV was more or less differentiated within a family, and even within the species, e.g. in the case of tomato. The stimulation of germination and/or increased seedling vigour was established in celery, green- and red-leafed basil, white and red cabbage, white clover and wild thyme. The same effect was noticed for the seeds of stratified broadleaf plantain and the positively photoblastic seeds of German chamomile germinated in darkness. The inhibition of seed germination and/ or reduced seedling vigour was demonstrated in case of caraway, dill and forget-me-not. Similar results were obtained in the experiments carried out in vitro and in the soil, hence it can be assumed that the indirect impact of SGV on plant habitat composition is likely. The interaction of SGV compounds with seed testa and seed phytohormones is discussed.

An Interplay of Light and Smoke Compounds in Photoblastic Seeds

“…In paper [29], smoke water from two plants, white willow and lemon eucalyptus, was used, and the authors reached the same results in the seeds of different horticultural crops. The author of [30] reported no difference in the effects of smoke that was generated by burning laboratory filter paper or dried meadow sward, which eliminated the potential stimulatory impact of coumarins, secondary metabolites that are abundant in grasses, on germination [31]. In another experiment, [32] the smoke water of an Australian grass, Themeda triandra (Poaceae), was used to treat the seeds of a cosmopolitan persistent weed, Avena fatua, of Eurasian origin.…”

“…However, the germination of smoke-treated seeds that were exposed to light was delayed. The reason for this could be the generation of reactive oxygen species by some secondary seed metabolites [30].…”

Smoke compounds aggravate stress inflicted on Brassica seedlings by unfavourable soil conditions

“…Soil can be a source of several stressors at the same time, whether it is too acidic, poor in nutrients, or contaminated with heavy metals. Grass burning (swailing), which is common but illegal in the Central Europe, brings another threat to the agricultural ecosystem (Cosgrove 2014, Bączek-Kwinta et al 2017. Smoke is an aerosol naturally dispersed and diluted but its rapid deposition in the soil after rainfall may trigger changes in plant communities.…”

“…Nowadays, attempts are also made to increase crop productivity with an aqueous smoke formulation (smoke water, SW) (Kulkarni et al 2008(Kulkarni et al , 2011. Smoke water may also emulate the mode of action of swailing-derived smoke on plants (Bączek-Kwinta et al 2017). However, the effects of smoke are complex and depend on the concentration of active substances, namely karrikins and trimethylbutenolide (Flematti 2013, Kochanek et al 2016, Pošta et al 2013, 2017.…”

“…Smoke water may also emulate the mode of action of swailing-derived smoke on plants (Bączek-Kwinta et al 2017). However, the effects of smoke are complex and depend on the concentration of active substances, namely karrikins and trimethylbutenolide (Flematti 2013, Kochanek et al 2016, Pošta et al 2013, 2017. Plants show different sensitivity to smoke (Reyes and Trabaud 2009, Dayamba et al 2010, Long et al 2011, Bączek-Kwinta et al 2017.…”