一种干热风对冬小麦千粒重影响的评估方法

A method for evaluating impact of dry-hot wind on 1000-kernel weight of winter wheat

为科学评估干热风灾害对冬小麦千粒重的影响,助力农业防灾减灾,采用叶片光合作用和干物质积累概念模型,于2010—2011、2011—2012年和2013—2014年在郑州农业气象试验站开展干热风控制试验研究。通过分析不同强度灾害与冬小麦叶片光合速率受胁迫程度的关系,对灾害影响下的光合作用速率进行修订,从而实现干热风灾害对千粒重影响的定量评估。结果表明:不同程度干热风使小麦叶片光合作用速率降低了0.66%~36.62%,日最高气温是造成胁迫最关键的气象因子;评估模型在正常年份、干热风典型年和试验条件下对千粒重的估算准确率均在95%以上,相对误差均小于4.5%;通过计算理想千粒重与实测千粒重的差值,评估得到,近年来代表站点灌浆前中期和临近收获期1~2 d轻干热风造成的千粒重损失为1~2 g,减产率为0~5%;其他时期不同程度干热风造成的千粒重损失为1~7 g不等,严重的减产率达12%~18%。综上,该评估方法有一定的适用推广性,能够相对真实地、动态地评估灌浆不同时期干热风对小麦千粒重的影响。

In order to estimate scientifically the influence of dry-hot wind on 1000-kernel weight of winter wheat and assist in agricultural disaster prevention and mitigation,conceptual models of leaf photosynthesis and dry matter accumulation was adopted,and dry-hot wind control tests were carried out at Zhengzhou Agrometeorological Experimental Station in years of 2010-2011,2011-2012 and 2013-2014.To evaluate quantitatively the impact of dry-hot wind on 1000-kernel weight,the relationship between different intensity of the hazard and stress degree of photosynthetic rate of winter wheat leaves was analyzed and the photosynthesis rate influenced by dry-hot wind was revised.The results showed that the rate of leaf photosynthesis was reduced by 0.66%~36.62%under different degrees of the hazard.Daily maximum temperature was the most critical factor causing the stress.In normal years,typical years of dry-hot wind and under field experimental conditions,the average accuracy of simulated 1000-kernel weight by the evaluation model was higher than 95%,and the relative error was less than 4.5%.By calculating the difference between a hypothetic ideal 1000-kernel weight and the measured value during the recent years at representative stations,the analysis indicated that the loss of 1000-kernel weight was about 1~2 g and the loss of the final yield was 0~5%when the light hazard of dry-hot wind lasted 1~2 days during the early middle stage of grain filling or approaching harvesting.In other stages,the loss of 1000-kernel weight was 1~7 g,and the yield reduction rate reached to 12%~18%under serious hazard condition.This method for evaluating the impact of dry-hot wind has a certain applicability,as it can objectively and dynamically assess the effects of dry-hot wind on grain weight during the different grain filling stages.