Photosynthetic and Yield Characteristics of Winter Wheat under Two Rounds of Irrigation during Spring

To clarify the effect of photosynthetic and yield characteristics of winter wheat under 7500 kg/hm2 grain yield when irrigated twice in spring, field experiments were conducted in the low plain of Hebei Province, which is in the Helonggang Region, an area suffering from serious water scarcity. The photosynthetic and yield characteristics of winter wheat were studied by using 8 wheat varieties and by irrigating water twice during spring from 2018 to 2019 under the condition of 42.6 mm of precipitation during the wheat growing season. Results showed that the yield of wheat varieties was 7805.3-9435.0 kg.hm(-2). Under the irrigation condition, the yield difference between strong gluten wheat and medium gluten wheat was irregular. In this study, both the average daily photosynthetic rate and photosynthetic potential were higher in Shinong 086 and lower in Shiluan 02-1, but the yield was higher in Shiluan 02-1. Varieties with high light efficiency need to be selected to obtain a high yield of wheat. Moreover, agronomic measures should be optimised, a reasonable population structure should be established and the contradiction between population development and ontogenesis must be addressed. The above conclusions can provide a theoretical basis for guiding wheat variety selection and supporting technology formulation.