Adjusting sowing date improves the photosynthetic capacity and grain yield by optimizing temperature condition around flowering of summer maize in the North China Plain

Dong Guo; Chuanyong Chen; Xiangling Li; Rui Wang; Zaisong Ding; Wei Ma; Xinbing Wang; Congfeng Li; Ming Zhao; Ming Li; Baoyuan Zhou

doi:10.3389/fpls.2022.934618

Adjusting sowing date improves the photosynthetic capacity and grain yield by optimizing temperature condition around flowering of summer maize in the North China Plain

Front Plant Sci. 2022 Aug 8:13:934618. doi: 10.3389/fpls.2022.934618. eCollection 2022.

Authors

Dong Guo^{1

2}, Chuanyong Chen³, Xiangling Li⁴, Rui Wang⁴, Zaisong Ding¹, Wei Ma¹, Xinbing Wang¹, Congfeng Li¹, Ming Zhao¹, Ming Li², Baoyuan Zhou¹

Affiliations

¹ Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture and Rural Affairs, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
² College of Agriculture, Northeast Agricultural University, Harbin, China.
³ Maize Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.
⁴ Hebei Key Laboratory of Crop Stress Biology, College of Agronomy and Biotechnology, Hebei Normal University of Science and Technology, Qinhuangdao, China.

Abstract

Adjusting the sowing date to optimize temperature conditions is a helpful strategy for mitigating the adverse impact of high temperature on summer maize growth in the North China Plain (NCP). However, the physiological processes of variation in summer maize yield with sowing date-associated changes in temperature conditions around flowering remain to be poorly understood. In this study, field experiments with two maize varieties and three sowing dates (early sowing date, SD1, 21 May; conventional sowing date, SD2, 10 June; delay sowing date, SD3, 30 June) were conducted at Xinxiang of Henan Province in 2019 and 2020. Early sowing markedly decreased the daily mean temperature (T _mean), maximum temperature (T _max), and minimum temperature (T _min) during pre-silking, while delay sowing markedly decreased those temperatures during post-silking. Under these temperature conditions, both varieties under SD1 at 12-leaf stage (V12) and silking stage (R1) while under SD3 at R1 and milking stage (R3) possessed significantly lower malondialdehyde (MDA) content in leaf due to higher activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) compared to SD2. Therefore, SD1 at V12 and R1 stages and SD3 at R1 and R3 stages for both varieties showed significantly higher photosynthetic capacity, including higher SPAD, F _v /F _m, P _n, T _r, and G _s, which promoted greater pre-silking dry matter (DM) accumulation for SD1 to increase the kernel number, and promoted greater post-silking DM accumulation for SD3 to increase the kernel weight, eventually increased the grain yield of SD1 and SD3 compared to SD2. Results of regression analysis demonstrated that T _mean, T _max, and T _min values from V12 to R1 stages lower than 26.6, 32.5, and 20.3°C are necessary for improving the kernel number, while T _mean, T _max, T _min, and accumulated temperature (AT) values from R1 to R3 stages lower than 23.2, 28.9, 17.3, and 288.6°C are necessary for improving the kernel weight. Overall, optimal temperature conditions around flowering can be obtained by early (21 May) or delay (30 June) sowing to improve the kernel number or kernel weight due to improved photosynthetic capacity, eventually increasing the grain yield of summer maize in the NCP.

Keywords: grain yield; photosynthetic capacity; sowing date; summer maize; temperature conditions.