The Nitrate Cumulation And The ALA, DCD Regulating Effect Of Tomato In Different Age Of Greenhouse

Tomato was the material in the experiment. The nitrate cumulation law of tomato and soil was investigated with age of the facilities by analyzing the nitrate content change of tomato and soil in four age of greenhouse. Different concentration (high, middle, low) of ALA and DCD application on tomato in different age of greenhouse (10 years,7 years, 5 years, 3years) induced the changes of NO₃^-, NO₂^- and nutritive quality content (sugar content, lycopene, total acid, VC,β-Carotene ). By using frequency analysis method, regression analysis method, correlative analysis method, difference significance test, revealed the security quality (the NO₃^-, NO₂^- content) and nutritive quality regulating effect of ALA and DCD application on tomato. The result as follows:(1) The nitrate content of tomato keep rising with age of greenhouse. It is related to the nitrate content rising of soil. Comparing the increasing speed of tomato fruit and soil, tomato fruit increased rapider than soil, the stimulated amplifying effect induced by the soil pollution maybe exist.(2) The nitrate content in different soil levels of old-aged greenhouses is higher than the young-aged ones. The nitrate content of old-aged and young-aged greenhouses decreased with the increase of depth in perpendicular direction, but the old-aged greenhouses'decreasing gradient were larger than the young-aged ones, it induced that the old-aged greenhouses'nitrate content was closed to the young-aged ones in deep layers of soil.(3) The NO₃^-, NO₂^- cumulation of tomato fruit was inhibited by the ALA and DCD application. The inhibition effect is better to the old-aged greenhouse with high nitrate and nitrite content. The NO₃^-, NO₂^- cumulation inhibition effect was increased obviously with the increasing concentration in the concentration range. The inhibition effect of NO₂^-was better than NO₃^-.(4) By applying ALA and DCD, not only the NO₃^-, NO₂^- cumulation was inhibited, but also improved the nutritive quality of tomato fruit, it's more distinct to the sugar content, lycopene and total acid in the 5 qualities. ALA had more distinctness effect than DCD. Comprehensive evaluate the effect to tomato fruit on the NO₃^-, NO₂^- cumulation inhibition and nutritive quality improving effect, ALA was better than DCD.(5) By applying ALA and DCD, the tomato fruit's change of the NO₃^-, NO₂^- content and the nutritive quality is correlated. The NO₃^-, NO₂^- cumulation inhibition quality and sugar content increase range presented obviously negative correlation, in the next place, it is also negative correlation to the increasing of the VC content. It implied that when people applying ALA or DCD, they would not only think over the effect to improve the tomato security quality, but also concentrate on the effect to improve the tomato nutritive quality, take into account comprehensively, strive after the win-win result.