不同时段低温冷害对玉米灌浆和产量的影响模拟

【目的】探讨不同时段低温冷害对玉米灌浆和产量的影响，为我国农业防灾减灾提供科学依据。【方法】基于WOFOST作物生长模型，采用数值模拟的研究方法，模拟分析了在苗期、抽雄期和灌浆期等2个发育期和3个发育期都发生不同程度低温对玉米灌浆和产量的影响。【结果】当2个发育期都发生低于下限温度2 ℃低温时，玉米灌浆时间推后1～6 d，减产6.29%～23.56%；当发生低于下限温度4 ℃低温时，灌浆时间推后1～7 d，减产6.82%～28.12%。当3个发育期都发生低于下限温度2 ℃低温时，玉米灌浆时间推后2～7 d，减产10.95%～31.7%；当发生低于下限温度4 ℃低温时，灌浆时间推后2～7 d，减产11.46%～41.47%。【结论】低温强度越大、持续时间越长，玉米减产越严重。低温发生的时段与程度不同，导致玉米减产的程度也不尽相同。

Modeling the impact of low temperature disaster during different development stages on grain filling processes and yields of maize

【Objective】 The study was to reconstruct the growing and development processes of crops and to study the impact of low temperature disasters during different development stages on the production of maize.【Method】 Based on the WOFOST crop growth model,numerical simulation method was adopted to simulate the impact of different intensity and continuous days of low temperature disaster occurred during two or three stages of seeding,tasseling and grain filling stage on grain filling processes and yields of maize.【Result】 When the temperature dropped 2 ℃ below the lowest temperature limit during two development stages of maize,the grain filling date would be delayed by 1-6 days and maize yield could be reduced by 6.29%-23.56%.When the temperature is 4 ℃ below lower temperature limit occurred during two development stages of maize,the grain filling date would be delayed by about 1-7 days and maize yield could be reduced about 6.82%-28.12%.Moreover,when the temperature is 2 ℃ below lower temperature limit occurred during three development stages of maize,the grain filling date would be delayed by about 2-7 days and maize yield could be reduced by about 10.95%-31.7%.When the temperature is 4 ℃ below lower temperature limit occurred during two development stages of maize,the grain filling date would be delayed by about 2-7 days and maize yield could be reduced by about 11.46%-41.47%.【Conclusion】 The yield reduction rate changed with the intensity and the occurrence stage.The higher intensity and longer continuous days the low temperature is,the larger the yield losses.