Precise ozone (O₃) flux models remain helpful to identify the sensitivity of crops and their cultivars under high O₃ levels by assessing biomass and yield losses under natural climate and future O₃ levels. In this study, we have evaluated the effects of O₃ on growth, biomass, and yield of four Indian wheat cultivars by exposure-linked as well as through flux-effect relationship-based analysis using two years of empirical data. Early and late sown cultivars were exposed to ambient O₃ (AO₃) and elevated O₃ i.e., ambient+20 ppb (EO₃). The POD₆SPEC (species-specific phytotoxic O₃ dose above a threshold of 6 nmol m⁻² PLA s^-1) on flag leaves for each cultivar and treatment was derived by using DO₃SE (Deposition of Ozone for Stomatal Exchange) model. Above-ground biomass was reduced more in early sown cultivars (26.1 %) than late sown (21.3 %) because of the larger negative impacts on plant growth under EO₃ treatment. Loss of grain yield under EO₃ exposure was high in early sown cultivars (30.5 %) compared to late sown (23 %) due to high stomatal O₃ uptake during the O₃ exposure period. Based on model outputs, early sown cultivars showed higher accumulated POD₆SPEC (1.6–3.75 mmol O₃ m⁻²) compared to late sown cultivar (0.65 to 1.97 mmol m⁻²). A negative linear relationship was obtained in above-ground biomass and grain yield concerning POD₆SPEC. The relationship showed that 0.284 mmol O₃ m⁻² accumulated POD₆SPEC is responsible for a 5% reduction of grain yield in early sown cultivars, while 0.393 mmol O₃ m^-2 accumulation is required for a 5% reduction in yield of late sown cultivars. The results also suggest that O₃ flux-effect relationship could be a valuable tool for assessing and predicting the risk of O₃ on wheat cultivars in India and for crop productivity models for predicting climate change impacts.

精确的臭氧（O ₃）通量模型通过评估自然气候和未来O ₃水平下的生物量和产量损失，仍有助于确定高O ₃水平下农作物及其品种的敏感性。在这项研究中，我们使用两年的经验数据，通过暴露关联以及基于通量效应关系的分析，评估了O ₃对四个印度小麦品种的生长，生物量和产量的影响。早播和晚播品种都暴露于环境O ₃（AO ₃）和升高的O _3，即环境+20 ppb（EO ₃）。POD ₆ SPEC（特定植物毒性O ₃对于每个品种，旗叶上的剂量高于6 nmol m ^-2 PLA s ^-1的阈值，并通过使用DO ₃ SE（用于气孔交换的臭氧沉积）模型得出处理结果。由于在EO ₃处理下对植物生长的负面影响更大，因此早播品种（26.1％）的地上生物量减少量大于晚播品种（21.3％）。由于在O ₃暴露期间气孔对O _3的摄取较高，因此，在早播品种中，EO ₃暴露下的谷物产量损失较高（30.5％），而晚播品种（23％）较高。根据模型输出，早期播种的品种显示出更高的累积POD ₆ SPEC（1.6–3.75 mmol O ₃m ^-2）相比，晚播品种（0.65至1.97 mmol m ^-2）。与POD ₆ SPEC有关的地上生物量与谷物产量之间呈负线性关系。该关系表明，在早期播种的品种中，积累的0.284 mmol O ₃ m ^-2的POD ₆ SPEC导致谷物产量降低5％，而为了使后期的产量降低5％，则需要积累0.393 mmol O ₃ m ^-2。播种。结果还表明，O ₃通量-效应关系可能是评估和预测O ₃风险的有价值的工具 在印度的小麦品种上，以及用于预测气候变化影响的作物生产力模型。