Application Of Digital Image Technology In The Diagnosis Of Grape N Nutrition

This thesis,through respectively setting the horizontal concentration gradients of six different nitrogens,namely 0,100,200,300,400,and 500kg/hm2 and conducting top dressing nitrogen fertilizer toward grapes in major growth period,this thesis measures the leaf areas,biomass,chlorophyll contents,photosynthetic rates,plant total nitrogen contents,soil inorganic nitrogen,fruits quality,yield and other physiological indexes and nitrogen nutrition indexes of Bixiang Wuhe and Red Barbara in major growth period,and analyzes the relations among such indexes and nitrogen application rate.Meanwhile,the canopy image of grapes in major growth period are gained by digital camera,and the relations among the red,green,and blue color values of canopy image,and other digital indexes,and the grapes nitrogen indexes.Nitrogen nutrition diagnosis method of leaf nitrate,soil inorganic nitrogen and chlorophyll meter etc are combined and utilized to establish the method of applying digital technology in grapes nitrogen nutrition diagnosis.Finally,the thesis,through comparison,selects the best digital indexes to recommend nitrogen in grapes’ major growth period.The results are as follows:During the major growth period,with the increase of nitrogen level,the leaf areas,biomass,chlorophyll contents and other physiological indexes of both kinds of grapes increase significantly.Top dressing of nitrogen fertilizer strengthens the photosynthesis of grapes,increases the accumulative volumes of nitrogen and organic matters,and improves the fruits quality.While the indexes increase stops at a certain value.Based on the correlation between nitrogen level and yield,it can be found that the best pure nitrogen volumes are 367.9kg/hm2 and 354.2kg/hm2 and under such condition the two kinds of grapes reaching their maximums.Through analysis to the leaf nitrate contents,soil inorganic nitrogen contents and yields of grapes,it can be found that the best nitrate concentrations for Bixiang Wuhe and Red Barbara in flowering period are 6.79mg/g and 6.57mg/g,in fruit setting period are 5.04mg/g and 5.47mg/g,and in fruit coloring period are 3.98mg/g and 4.4mg/g.During flowering period,the best soil inorganic nitrogen contents are 204.4kg/hm2 and 203.1kg/hm2,182.7kg/hm2 and 173.9kg/hm2 in fruit setting period and 189.5 kg/hm2 and 189.9 kg/hm2 in fruit coloring period.It is measured through chlorophyll meter that the SPAD values and nitrogen application rates and nitrogen nutrition indexes of grapes in different periods are in significant correlation and digital indexes can be used for grapes nitrogen nutrition diagnosis.The relations among digital indexes of grapes’ canopy image and nitrogen application rates and nitrogen nutrition indexes under different nitrogen levels are analyzed.The research shows that the digital image technology can be used in grapes nitrogen nutrition diagnosis.Among all digital indexes,the correlations among G/B and nitrogen application rates and other nitrogen nutrition indexes are the best,followed by G/(R+G+B),and these can be used as the indexes for grapes’ nitrogen nutrition diagnosis.The results of the analysis to the grapes canopy images acquired in different angles and to that whether the background is removed show that: there’s no significant difference in the color parameters of the canopy imaged acquired in different angles,and 30°~60° is suggested in practical operation.And there are significant different between the images with background and without background,so the background shall be removed in later processing after being acquired.The grapes’ nitrogen nutrition diagnosis standards are established based on the G/B values of grapes canopy images under different nitrogen application rates and the soil inorganic nitrogen contents:During the flowering period of Bixiang Wuhe,when the G/B value is lesser than 1.515,the plant is in short supply statues of nitrogen;when the G/B value is in 1.515-1.523,the plant is in moderate supply statues of nitrogen;when the G/B is higher than 1.526,the plant is in oversupply statues of nitrogen.During the fruit setting period of Bixiang Wuhe,when the G/B value is lesser than 1.383,the plant is in short supply statues of nitrogen;when the G/B value is in 1.383-1.39,the plant is in moderate supply statues of nitrogen;when the G/B is higher than 1.39,the plant is in oversupply statues of nitrogen.During the fruit coloring period of Bixiang Wuhe,when the G/B value is lesser than 1.29,the plant is in short supply statues of nitrogen;when the G/B value is in 1.29-1.318,the plant is in moderate supply statues of nitrogen;when the G/B is higher than 1.318,the plant is in oversupply statues of nitrogen.During the flowering period of Red Barbara,when the G/B value is lesser than 1.473,the plant is in short supply statues of nitrogen;when the G/B value is in 1.473-1.497,the plant is in moderate supply statues of nitrogen;when the G/B is higher than 1.497,the plant is in oversupply statues of nitrogen.During the fruit setting period of Red Barbara,when the G/B value is lesser than 1.322,the plant is in short supply statues of nitrogen;when the G/B value is in 1.322-1.363,the plant is in moderate supply statues of nitrogen;when the G/B is higher than 1.363,the plant is in oversupply statues of nitrogen.During the fruit coloring period of Red Barbara,when the G/B value is lesser than 1.413,the plant is in short supply statues of nitrogen;when the G/B value is in 1.413-1.447,the plant is in moderate supply statues of nitrogen;when the G/B is higher than 1.447,the plant is in oversupply statues of nitrogen.