Do phytotoxic allelochemicals remain in ashes after burning Chrysanthemoides monilifera subsp. monilifera (boneseed)?

Australia is facing challenges in controlling Chrysanthemoides monilifera subsp. monilifera(boneseed). However, burning has achieved some success in this regard. We aimed to investigate the comparative phytotoxicity of boneseed dried powder and ashes(burnt at 450℃ and250℃). Phenolic compounds in powder and ashes were measured using Folin–Ciocalteu assay and HPLC. The phytotoxicity of boneseed powder and ash extracts was assessed through germination bioassay on Lactuca sativa and the phytotoxicity of litter and ashes was evaluated using field soil, both in growth chamber. Burning of boneseed reduced total phenolics in ashes of boneseed organs by 99% and 100% both at high and low temperatures. The four phenolic compounds that were detected in boneseed were either absent or at negligible levels in the ashes,with inversely related to temperature. Both boneseed ash extracts and litter ash-mediated soil significantly reduced phytotoxicity displaying increased germination, biometric and biochemical parameters of test species compared with unburnt powder extracts and litter powder-mediated soil respectively, with greater reduction of phytotoxicity found for ashes produced at the lower temperature. Interestingly, the ash extracts and litter ash-mediated soil were found to stimulate some of those parameters of the test species compared to control. There was no excessive reactive oxygen species(ROS) produced in test species exposed to ash extracts compared with unburnt powder extracts. These findings suggest that burning of boneseed is an appropriate method of weed control and that this approach will reduce phytotoxicity of this species on native plants.     

Income inequality and CO2 emissions: nonlinear evidence from Turkey

The income inequality-economy link has been argued by researchers a long time. But the impact of income inequality on environmental pollution is a new investigation topic for developing countries. Turkey is well known as an emerging economy which has a high level of income inequality and CO₂ emissions. Therefore, this paper concentrates on the income inequality-CO₂ emissions link in Turkish economy by applying a nonlinear analysis. This paper integrates economic growth and financial development to the CO₂ emissions specification over the period of 1987–2019. We employ the nonlinear autoregressive distributed lag approach to explore the long-run nonlinear linkages between the series. Our findings reveal an asymmetric cointegration among variables. Positive and negative income inequality shocks positively affect CO₂ emissions implying that positive and negative shocks of income inequality enhance CO₂ emissions in the long run. Negative economic growth shocks decrease CO₂ emissions, while positive shocks to financial development increase CO₂ emissions in the long run. We provide important policy suggestions that might be useful to the policymakers to decrease CO₂ emissions in Turkey.