The Effects Of Environmental Factors On Growth And Gross Photosynthesis Of Grapevines

All the plants, including grapevine, are always affected by the environment factors in many ways, and vice verse, the plants will react to the stresses instantaneously. The crucial question is whether we can capture these information and analysis them. The digitalization of grapevine production is the case of realizing the precise management. Water, temperature, light and CO2 concentration are important factors that affect plant growth. Finding the lower limit of rootzone water potential and the most favorite gross photosynthesis environment will be helpful for building the growth model of grapevine.(1)The effect of root-zone soil water potential (RWP) on the simultaneous diameter of shoot and fruit was assessed in 3-year potted grapevine (Vitis vinifera×V.labrusca cv.Kyoho) with digital photograph during fruit expanding stage and veraison. The time series analysis theory was applied for data analysis. The results showed that: During fruit expanding stage, the trend of the fruit diameter begins to decline when the RWP is lower than -30 KPa. The trend of the fruit diameter slumps when the RWP reach -160 KPa during veraision. So the irrigation should be carried out when the RWP decreased to -30 KPa during fruit expending stage, and -160 KPa during veraison. (2)Calculation and analysis system were established for crop gross photosynthesis measurement in climate chambers and effects of climate factor on grapevine(Vitis vinifera×V.labrusca cv.Kyoho)canopy photosynthesis were studied. The results showed that elevated CO2 obviously increased gross photosynthesis (Pgc), especially under high radiation conditions. Pgc increased 38.77% and 50.15% when CO2 concentration rose from 400 to 700 and 1000μmol/mol respectively. Elevated CO2 also enhanced photochemical efficiency (αc) and maximum gross photosynthesis rate (Pgc,max). Temperature had a high influence on Pgc also, higher temperature reducedαc and Pgc,max increased under low CO2 condition. The gross photosynthesis rate increased as the CO2 concentration increase. Temperature that maximized Pgc at different (400...