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| DOI：10.13522/j.cnki.ggps.2020708 |
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| Sensitivity of Winter Wheat to Drought Occurring at Different Growth Stages |
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XU Hu, JIANG Shangming, YUAN Hongwei, LIU Jia, JIN Juliang
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1.Key Laboratory of Water Conservancy and Water Resources of Anhui Province, Water Resources Research Institute of
Anhui Province and Huaihe River Commission, Ministry of Water Resources, Hefei 230088, China;
2. School of Civil Engineering, Hefei University of Technology, Hefei 230009, China;
3. Institute of Water Resources and Environmental Systems Engineering, Hefei University of Technology, Hefei 230009, China
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| Abstract: |
| 【Background and objective】Sensitivity of crop to drought is a measure of the response of its growth and yield to water stress occurring at different growth stages. It is a key parameter characterizing the transition from drought risk to drought loss. The objective of this paper is to experimentally investigate how drought stresses occurring at different growth stages of winter wheat affect its eventual yield.【Method】The experiment was conducted in a winter wheat field, and drought of different degrees was imposed at different growth stages. In each treatment, we measured the changes in total dry matter accumulation and the final yield. A sensitivity function was derived based on the growth rate of the dry matter accumulation to assess the impact of the droughts.【Result】①Drought occurring at tillering stage reduced the growth rate of the total dry matter accumulation, but the reduced rate did not increase at significant level as the drought stress increased because the occurrence of the drought in this period stimulated roots to go deep to forage water in subsoil; this benefit continued to the late stage of the wheat.② Occurrence of mild drought at jointing or booting stage did not have significant effects on growth and development of the wheat, but the wheat was very sensitive to severe drought occurring at these stages.【Conclusion】The growth rate of the total dry matter accumulation decreased asymptotically as the drought stress occurring at tillering stage increased. Since the drought did not inhibit dry matter accumulation, insufficient irrigation can be implemented at this stage without compromising yield. The wheat was sensitive to severe drought at the jointing or booting stage, and soil water content at these stages should be kept higher than 55% of the field capacity. The wheat was very sensitive to drought at heading and flowering stage and even a mild drought could significantly hinder the crop growth; soil moisture at this stage thus hould be kept higher than 75% of the field capacity. |
| Key words: wheat; sensitivity to drought; drought stress; relative growth rate; sensitivity function |
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