请优化以下论文的讨论部分优化得更具有逻辑性和学术性42 Sources of variation in yield under different treatmentsThe results of this study suggest that the interannual climate combined with irrigation treatments significantly inf

The present study investigated the sources of variation in wheat yield under different irrigation treatments and interannual climate variability. The results revealed that weather conditions and water management practices significantly influenced crop productivity, which is consistent with previous research (Gao et al., 2022; Wang et al., 2022). The interannual variation in yield for the three treatments was observed to be 9.4%, 9.5%, and 10.5%, respectively, indicating that different treatments had different sources of variation.

The Con and Min treatments showed that variation was mainly derived from thousand-kernel weight and ear number, respectively. The Con and Opt treatments were affected by weather conditions resulting in interannual yield variability, consistent with previous findings that increased early post-flowering temperature significantly reduced wheat thousand-kernel weight. Dry heat winds usually occurred during late seed filling, causing rapid senescence and death of winter wheat, resulting in reduced seed filling rates.

In contrast, the yield variation in Min was mainly derived from the ear number, which is consistent with the results of previous studies (He et al., 2017; Wang, Liu, Asseng, Macadamd, & Yu, 2017; Zhang, Qin, Chen, Shao, & Sun, 2017). The present study found that grain yield was closely related to the amount of grain per unit area. The stem elongation period to the beginning of flowering is the most critical period that determines the number of wheat seeds, during which soil water deficit in the uppermost soil layer will severely reduce the number of seeds. This is consistent with the results of the present study, which showed that rainfall during the ear number formation stage is an important contributor. The number of ears was mainly influenced by the rainfall conditions at the formation stage. In 2019, the rainfall before flowering amounted to 84.3 mm, the highest value in six years, and therefore the number of spikes per mu in that year was 743.8, also the highest value in six years.

In summary, this study highlights the importance of considering weather conditions and water management practices in crop productivity, and the sources of variation in yield under different treatments. The findings provide valuable insights into the factors that influence wheat yield and can be useful in developing effective strategies for improving crop productivity. Further research is needed to explore the underlying mechanisms and develop more accurate models to predict crop yield under different scenarios.