Abstract:

【Objective】 The experiment aims to study how the winter wheat growth and yield response to the higher night temperature. 【Method】 Using winter wheat as experimental material, higher night temperature treatment (HNT) of a 2.5℃ increase was set with infrared heaters (HNT from April 3 at the jointing stage to June 15 at the wheat harvest), relative to normal night temperature treatment (control), to determine the effects of HNT on winter wheat growth and yield. 【Result】 Compared to the control, when winter wheat planted at 2.5℃ HNT, the growth duration was shorter, the phenological phases were earlier and yields were decreased significantly. In earlier phenological phase of winter wheat in HNT, the milk ripe stage was 4 days earlier than those in the control, the mature date was 5 days earlier, other phenological dates were 1-2 days earlier than those in the control, and the milking processes of wheat in HNT were shorter 5 days. Compared to the control, the winter wheat yields in higher night temperature (HNT) treatment were reduced by 26.6% as HNT caused a significant increase in infertile tillers, fewer spikelet number, fewer grains per spike, and lower 1000-grain weight. 【Conclusion】 The winter wheat yields with spring nocturnal warming were decreased significantly. The important reasons for yield decrease include a decreased growth duration, shorter milking processes, and earlier phenological date. As the growth duration become shorter, the yield compositions of wheat in HNT changed. The significant decrease in infertile tillers, non-productive panicles, and fewer grains per spike were the main reasons for the yield decline of wheat in HNT. Another reason for yield decline was that HNT could make a higher evapotranspiration which would induce soil moisture decrease. Soil moisture decrease due to a higher evapotranspiration in HNT may be another contributor to yield decline. As expected, the adaptation measures should be considered to cope with the impacts of global warming on crops, and further researches and assessments need to be conducted.

Key words: climate change, higher night temperature, winter wheat, yields, adaptation