Response mechanism of spring maize growth to continuous drought in arid area
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DOI:10.7606/j.issn.1000-7601.2020.06.30
Key Words: continuous drought  spring maize  growth indicators  soil water storage  soil water deficit
Author NameAffiliation
JIANG Jufang Wuwei Meteorological Bureau of Gansu Province, Wuwei, Gansu 733000, ChinaInstitute of Arid Meteorology of China Meteorological Administration, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Change and Disaster Reducing of CMA, Lanzhou, Gansu 730020, China 
WANG Runyuan ;Institute of Arid Meteorology of China Meteorological Administration, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Change and Disaster Reducing of CMA, Lanzhou, Gansu 730020, China 
ZHANG Kai ;Institute of Arid Meteorology of China Meteorological Administration, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Change and Disaster Reducing of CMA, Lanzhou, Gansu 730020, China 
YANG Hua Wuwei Meteorological Bureau of Gansu Province, Wuwei, Gansu 733000, China 
WEI Yuguo Wuwei Meteorological Bureau of Gansu Province, Wuwei, Gansu 733000, China 
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Abstract:
      Drought restricts crop growth and yield formation. To scientifically relieve drought, it is necessary to make clear about the beginning time and response mechanism to the drought. This paper took the spring maize Kehe 28 as the material and the two treatments of normal irrigation and continuous drought were set up during the whole growth stage. The changes of spring maize, the early signals of drought stress, the period of significant influence, and the threshold of soil moisture were explored during drought occurrence and development in the arid area. The results showed that: (1) To capture the early signals of the drought effects on field indicators during drought years, water content of leaves started to decrease in 21 d after experimental treatment, plant height and leaf area growth were affected by 28 d after experimental treatment, and dry matter accumulation of leaves was affected by 32 d after the treatment. (2) In the initial period when the significant effects of continuous drought were lifted, plant height, leaf area per plant, dry matter accumulation, and water content of each organ were 49, 56, 63 d, and 70 d after experimental treatment, respectively. The minimum soil water storage were 74.6, 69.0, 58.0 mm, and 56.5 mm, and the maximum soil water deficits were 30.4, 37.8, 47.2 mm, and 43.6 mm, respectively. (3) The effects of continuous drought on dry matter accumulation and moisture content of spring maize were: leaves > sheaths > stems > ears, and the continued drought caused a small economic output. (4) The effects of continuous drought on field indicators were significant at the jointing stage, the tasseling stage was the largest, and the milk ripening stage had a negative increase. (5) The effects of continuous drought on the yield composition: compared with normal irrigation, the ear length decreased by 70%, ear diameter decreased by 45%, bare tip length increased by 33%, seed weight decreased by 73%, seed weight decreased by 84%, and theoretical yield decreased by 85%. (6) The drought duration of 21 d was the early signal of drought in spring maize in the arid area, and the drought duration of 49 d was irreversible period. Spring maize was less effected on yield for less or no irrigation during the three to seven\|leaves stage and late filling stage. The jointing stage water and tasseling stage water were the key to ensure output.