Few studies have evaluated the effect of humid weather on wheat productivity and yield gaps. Humid weather conditions before, during, and after flowering cause losses associated with Fusarium head blight and pre-harvest sprouting. To increase the actual yield, efforts such as ensuring that farm yield is commensurate with yield potential via wheat breeding activities have been made in the wake of increasingly adverse climatic conditions. In the present study, the time-series wheat yield gap (simulated yield potential minus actual on-farm yield) was analyzed for the 1984–2020 period in the humid region of northern Japan, where major varieties have been replaced with more productive (high yield, preharvest resistant, and Fusarium head blight-resistant) ones almost every decade. The periodical introduction of alternative varieties has altered the meteorological factors responsible for yield gaps. Older varieties, ‘Chihoku-komugi’ and ‘Hokushin,’ exhibited higher sensitivity to atmospheric humidity before harvest and after the heading period. A new high-yield variety, ‘Kitahonami,’ with increased floret numbers, reduced the periodical mean yield gap from 1.95 Mg/ha to 1.14 Mg/ha, whereas the yield gap often expanded under vapor pressure deficit of < 0.3 kPa during the flowering period. The results indicated that ‘Kitahonami’ yield potentially depends on the yield rate of potential fertile florets, which leads to its vulnerability to short-term rainy, humid weather during the flowering period. Current breeding strategies reduce humidity damage at sensitive duration of preharvest sprouting-resistant, and Fusarium head blight-resistant, while the emerging yield gap factors continue to reflect the traits that could be targeted for improvement.

很少有研究评估潮湿天气对小麦生产力和产量差距的影响。开花之前、期间和之后的潮湿天气条件会导致与镰刀菌赤霉病和收获前发芽相关的损失。为了提高实际产量，在气候条件日益不利的情况下，通过小麦育种活动确保农场产量与产量潜力相称等努力。在本研究中，分析了 1984-2020 年日本北部潮湿地区的时间序列小麦产量差距（模拟产量潜力减去实际农场产量），那里的主要品种已被产量更高的（高产量、抗收获前和抗镰刀菌枯萎病）几乎每十年一次。替代品种的定期引入改变了造成产量差距的气象因素。较老的品种“Chihoku-komugi”和“Hokushin”在收获前和抽穗期后对大气湿度表现出更高的敏感性。小花数量增加的新高产品种 'Kitahonami' 将周期性平均产量差距从 1.95 Mg/ha 减少到 1.14 Mg/ha，而在开花期间，当蒸气压不足 <0.3 kPa 时，产量差距经常扩大时期。结果表明，'Kitahonami' 的产量可能取决于潜在可育小花的产量，这导致其在开花期容易受到短期多雨、潮湿天气的影响。当前的育种策略减少了收获前抗发芽敏感期的湿度损害，