Ethylenediurea (EDU) spray effects on willows (Salix sachalinensis F. Schmid) grown in ambient or ozone-enriched air: implications for renewable biomass production

Abstract Ground-level ozone (O 3 ) is a widespread air pollutant causing extensive injuries in plants. However, its effects on perennial energy crops remain poorly understood due to technical difficulties cultivating fast-growing shrubs for biomass production under O treatment the field. Here we present results of two-year evaluation framework which willow ( Salix sachalinensis F. Schmid) were exposed ambient (AOZ) or elevated (EOZ) two successive growing seasons (2014, 2015) and treated with 0 (EDU0) 400 mg L −1 (EDU400) ethylenediurea spray second season. In 2014, EOZ altered chemical composition both top young fallen leaves, novel mechanism decreasing Mg leaves while highly enriching it was revealed EOZ. 2015, EDU400 alleviated EOZ-induced decreases leaf fresh mass dry ratio (FM/DM) per area (LMA). While protected against suppression maximum rate at can fix carbon A max -asymptomatic did not alleviate rates carboxylation V Cmax electron transport J chlorophylls , b + same type leaves. -symptomatic however, indicating different mode action EDU between Extensive herbivory occurred only AOZ-exposed plants, leading suppressed production, also led similar (EDU0 × vs. EOZ). 2016, carry-over evaluated following cropping transplantation into new plots. Effects preceding extended third season form ratoon effect Although when applied there no absence 2016. The this study provide mechanistic understandings modes enlighten cultivation as crop.