Study On Water Saving And Quality Control Of Tomato Based On Alternate Partial Root-zone Irrigation Combined With Double-root-grafting

Fresh water shortage is an important crisis facing many countries and regions.In the process of water resources utilization,agricultural irrigation water consumption ranks first,which is the main cause of water resources shortage.For the scientific problems of how to maintain water saving,quality regulation and stable production,the effects of alternating salty water and root irrigation and conventional freshwater irrigation,alternating water,salt water,salt water)and grafting(root and double root grafting)on tomato growth,photosynthesis,yield,quality,root matrix characteristics and water production efficiency.The main research results obtained are as follows:(1)Under sufficient brackish water irrigation,double-root grafting has significantly improved the tomato quality on the basis of stable yield.Sufficient brackish irrigation reduced autoroot tomato production compared to conventional freshwater irrigation,but had no significant effect on the yield of double-root grafted tomatoes.Moreover,adequate brackish irrigation significantly improved the quality of double-root grafted tomatoes,with the best effects on soluble sugars and soluble solids.The content of soluble solid materials under brackish water irrigation increased by 39.5%～47.2%(compared with conventional freshwater irrigation),up to 12.5%.(2)The yield of double-root grafted tomato is mainly significantly affected by the irrigation amount of brackish water and the interval days(rather than EC value).The yield of double-root grafted tomato increased with increasing irrigation volume and decreased with increasing interval days.Considering the yield,quality and water production efficiency of double root grafted tomato under alternating irrigation of brackish water root area,the optimal brackish water irrigation scheme is:irrigation amount(1.2mm before fruit,2.4mm after fruit),3 days of irrigation interval,and EC value of 3.5mS/cm.(3)Alternate irrigation in the root areas can effectively improve the utilization efficiency of irrigation water.Compared with conventional irrigation(except for consistent treatment with control irrigation water),alternating irrigation reduced irrigation water by 26.78%～75.71%,while the water production efficiency increased by 12.9%～37.8%.(4)Under alternating irrigation of brackish water root area,double root grafting is better than self-root cultivation.Compared with autoroot,double-root grafting can effectively improve tomato plant growth,improve the efficiency of irrigation water,and reduce the adverse effects of brackish water on tomato yield.(5)Using brackish water and fresh water to irrigate the rootstock and scion roots of double-root grafted tomatoes,respectively,which can maximize the production efficiency of irrigation water.Compared with conventional freshwater irrigation,brackish water(rootstock root)-freshwater(scion root)alternating irrigation significantly improved tomato quality(soluble sugar and soluble solids content by 35.2%and 22.4%,respectively),indicating that brackish-freshwater root area alternating irrigation and double root grafting can simultaneously improve tomato quality and water utilization efficiency,and achieve water saving and quality regulation.Considering the above results,although brackish water irrigation can reduce the production of self-root tomato,double root grafting can guarantee tomato yield and significantly improve fruit quality under brackish water irrigation.Alternate irrigation in the root area,combined with double root grafting can maintain the yield and improve the quality while effectively improving the production efficiency of irrigation water.The coordination of brackish water and fresh water alternating irrigation and double root grafting is one of the effective strategies to realize water saving and quality improvement of tomato in water shortage areas.