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| DOI：10.13522/j.cnki.ggps.2017.0543 |
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| Responses of Physiological and Growth Traits and the Yield of Maize to Water Deficit Occurring at Different Growth Stages |
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ZHANG Zhijun, LIU Haijun, ZHANG Liwei, LIU Yu, DING Mei, ZHU Mingcheng
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College of Water Sciences, Beijing Normal University, Beijing 100875, China; School of Civil Engineering and Water Conservancy, Ningxia University, Yinchuan 750002, China
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| Abstract: |
| 【Objective】 The purpose of this paper is to investigate the effects of water deficit occurring at different growth stages on stomatal conductance, evapotranspiration and yield of maize. 【Method】 A two-year pot experiment was carried out with water deficit occurring at stages of early jointing (A), late jointing (B), tasseling (C) and grain-filling (D) of maize growing in Lishu experimental station of China agricultural university in Jilin province. We examined four treatments, with water deficit lasting 1, 3, 5 and 7 days, respectively (C1, C3, C5 and C7). The control (CK) was full irrigation without water deficit. 【Result】 ①The stomatal conductance decreased with the increase in water deficit, especially in C5 and C7; when the volumetric soil water content was less than 0.15, the stomatal conductance reduced to less than 50 mmol/(m2·s). ②Under water stress, the evapotranspiration was lower than that in the CK. Water deficit lasting for one day at any of the four growth stages did not result in noticeable detrimental impact, except C3 where the evapotranspiration only slightly decreased. In contrast, a prolonged water deficit lasting five or seven days at any stage significantly reduced the evapotranspiration compared to the CK. When the volumetric soil water content was less than 0.15, the evapotranspiration was only one third of that at normal moisture content. ③The yield and yield traits decreased with water stress increasing, and a seven-day water deficit could reduce the average yield by 49.1%. Water stress at any stage reduced the yield, especially when occurring at the tassel period. The bald tip was the most significant trait for yield reduction. 【Conclusion】 We can conclude from our experiment that water deficit for one to three days had limited effect on eco-physiological traits and the yield of the maize, and the volumetric water content of 0.15 can be used as an critical water content to diagnose water deficit. We also found top-upping the moisture content to sufficient level at tasseling stage after water deficit can help achieving high yield. |
| Key words: maize; water deficit treatment; stomatal conductance; evapotranspiration; soil moisture; yield |
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