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Objective: To explore the root zone water change on processing tomato root growth regulation, deepen understanding on Growth and Yield Formation regulation, clear arid zone drip irrigation under plastic film processing tomato yield and water use efficiency under physiological regulatory mechanisms for processing tomato increase production, improve water use efficiency, and provide reference for further optimization of the irrigation system. : 2 years of field trials, experimental treatments, including two irrigation methods: the drip tube under the surface of the film surface drip irrigation DI and drip irrigation pipe buried below the surface of 30cm underground drip irrigation SDI. Ground drip irrigation D11, DI2, DI3 three water treatment 0-60cm soil profile moisture content is set to field capacity (80 ± 5)% (60 ± 5)%, (40 ± 5)%. The subsurface drip SDI1, SDI2, SDI3 three processing amount of irrigation and irrigation time ground drip irrigation DI1, D12, DI3 same. Results: (1) the relative water deficit, the vertical distribution of processing roots, subsurface drip treatment significantly increased the diameter of the processing tomato 0-1mm root unit area of ??root length density, root weight density, the initial impact -30cm root growth, in the late principally affected 30cm root growth. Red berries of the underground drip irrigation of processing tomato roots in the soil 30-80cm vertical distribution of weight distribution was significantly higher than the ground drip irrigation. 14 days after flowering ground drip irrigation and subsurface drip treatment root length density was no significant difference in the 0-30cm soil layer, but the red berries of the underground drip irrigation root length density was significantly greater than in the 30-80cm soil surface drip irrigation, especially in the state of relative moisture deficit. (2) in processing root level distribution, the distribution of red berries of the underground drip irrigation roots evenly distributed than surface drip irrigation, water treatments root length density was significantly greater than in the horizontal distribution of surface drip irrigation, especially in the relative water deficit state . (3) after anthesis soil water regimes on processing tomato dry matter accumulation and distribution in 14 days after flowering, the relative water deficit significantly reduce the processing tomato leaf area index; red berries and surface drip irrigation, the relative water deficit significantly improve subsurface drip irrigation of processing tomato leaf area index. Drip irrigation after flowering under 14 world SDI2, SDI3 processing plants of shoot growth were significantly lower than DI2, DI3, and SDI2 and DI2 between SDI3 DI3 there are significant differences in plant height; red berries of subsurface drip treatment plants overall and main stem, number of branches, buds, significantly higher than the ground drip irrigation subsurface drip SDI2 is, SDI3 plants, whether underground or in the amount of shoot growth have been the rapid growth and development, was significantly better than DI2 DI3 to SDI2 and DI2 SDI3 DI3 there was a significant difference. 14 days after flowering moisture treatments on surface drip and subsurface drip irrigation of processing tomato root dry weight density had no significant effect, but the red berries of a significant increase in subsurface drip irrigation to deal with the root dry weight density. (4) formed in the soil water change on water use efficiency and yield of processing tomato, red berries of the processing tomato, SDI2, SDI3 unit of dry matter, water consumption was significantly lower than DI2, DI3 instructions in the processing tomato flowering and surface drip irrigation, subsurface drip irrigation water use efficiency, especially in the relative water deficit state. (5) changes in soil moisture stages of processing tomato process after flowering DI1 first to reach the fruiting period, followed by SDIl, DI2, SDI2, DI3, last SDI3 ground drip irrigation subsurface drip corresponding earlier reach the fruit set; late, DI3 earliest to reach the red berries of followed the DI2, SDI3, SDI2, SDI1, the last is DI1. Conclusion: (1) adequate soil moisture conditions, subsurface drip irrigation and surface drip irrigation, root growth characteristics was no significant difference. On the horizontal distribution of roots underground drip irrigation root distribution than surface drip irrigation roots evenly distributed. In the treatment of water relative deficit compared to surface drip irrigation, subsurface drip irrigation significantly conducive to processing tomato root growth. (2) relative to the water deficit in the red berries of the underground drip irrigation groups on the overall photosynthetic rate was significantly higher than the ground drip irrigation and leaf chlorophyll content and contrast; 14 days after flowering relative water deficit significantly inhibited the processing tomato on the ground growth; red berries and ground drip, relative water deficit significantly conducive to the growth of subsurface drip irrigation of processing tomato aerial parts. (3) processing in the state of relative deficiency of water, subsurface drip irrigation water use efficiency was significantly higher than the ground drip irrigation. Relative water deficit subsurface drip from the weight of the whole number of single fruit was significantly better than surface drip irrigation. (4) Judging from the entire stages of processing tomato, in sufficient water status, compared with the ground drip irrigation, subsurface drip irrigation on processing tomato growing process is not significant, but in a state of relative water deficit, the subsurface drip obvious postponed the process of growth and development of the processing tomato fruit ripening was delayed. (5) Compared with the ground drip irrigation, subsurface drip irrigation under water deficit state, although improved processing tomato lycopene content, but reduces the formation of fruit flavor substances, free amino acids, soluble protein, soluble sugar, soluble acid content, soluble solids content and fruit sugar to acid ratio, an increase of nitrate content of fruit, therefore, reduce fruit quality.
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