Effect Of Magnesium(Mg) Application In Grape Wih Mg Nutrient Deficiency

In southern China by factors such as climate and soil acidity is stronger,Mg easy migration and leaching loss of soil,capacity reduction,soil for magnesium plant in magnesium deficiency,growth and development is affected,aiming at this problem,this experiment in longquanyi district has diagnostic vacancies on magnesium etiolated 5 years' giant peak grapes as the research object,split plot experiment was carried out,main area set up four soil magnesium sulfate gradient,0 kg/hm2,7.5 kg/667m2,10 kg/667m2,12.5 kg/667m2,in the fall with basal,deputy district set three spraying on the leaf,magnesium sulfate concentration was 0%,0.2%,0.4%,to explore magnesium supplement in magnesium deficiency grape mineral nutrition absorption,yellowing control effect,photosynthetic rate,chlorophyll fluorescence characteristics,active oxygen metabolism,leaf starch accumulation of dry matter and the influence of the fruit yield,quality,and for the vineyard obtains the best soil filling effect of magnesium and spraying on the leaf was the concentration of magnesium fertilizer.The results of the study are as follows:1.The comparison of the differences in mineral content in the leaves and fruit,after the analysis of the correlation between magnesium and various mineral elements,found that:(1)soil and foliar spraying magnesium fertilizer significantly increased the magnesium content of grape leaves and fruit of magnesium deficiency;(2)Appling proper amount of magnesium fertilizer contributed to the lack of magnesium plant growth and development,enhance the plants on the absorption of calcium,potassium,but a glut of ShiMei,magnesium and potassium calcium absorption of antagonism,suppresses the plant to absorb potassium calcium;(3)ShiMei reduces the plant to absorb zinc,magnesium blade has very significant negative correlation with zinc content,but no significant effect on iron and copper;(4)handle S7.5F0.4(autumn,10 kg/667m2 magnesium sulfate fertilizer,soil in mid-may,the middle of June,in mid-july foliar spraying 0.4%magnesium sulfate fertilizer)leaves magnesium,potassium,iron,manganese content in the appropriate standard,high calcium,zinc and low quantity but not the lack of plants to various mineral absorption is better.2.The mature leaf etiolation rate survey,the Li-6400 xt portable photosynthetic apparatus and a portable modulated chlorophyll fluorometer PAM-2500 respectively on the leaves of photosynthesis and chlorophyll fluorescence parameters were determined,and the determination of leaf chlorophyll content found:(1)soil and spraying on the leaf appropriate amount magnesium fertilizer can significantly increase the chlorophyll and carotenoid content,effectively reduce the rate of leaf etiolation,enhance stomatal conductance promoted the C02 and water into the blade,significantly improve the leaf net photosynthetic rate,but when the amount is too large,magnesium and potassium ion antagonist,inhibit the uptake of potassium by plants,thereby inhibiting the pores open,resulting in a loss of net photosynthetic rate.(2)lack of magnesium,grape leaf Yield,ETR,Fv/Fm,qP,qN the lowest and highest F0,PSII reaction center has received the injury,photosynthetic activity is reduced,the original light energy conversion efficiency drops,electron transfer ability weak,PSII activity by inhibiting potential,and is suitable for ShiMei leaf Yield,ETR,Fv/Fm,qP,qN remain at high levels,F0 is reduced,that a moderate amount of ShiMei increased PSII antenna pigment of photochemistry dissipation ability and alleviate the damage optical system,at the same time maintain PSII situ activity of light energy conversion efficiency and potential.3.Through to the leaf nitrate reductase activity and organic matter content and fruit quality were determined,found that(1)lack of large amount of magnesium and ShiMei led to the decrease of the grape leaf nitrate reductase activity,soluble protein and soluble sugar content decreased,but the accumulation of starch content,the skin color and fruit quality reducing(2)moderate ShiMei may help improve the activity of nitrate reductase,increase content of soluble protein and soluble sugar,starch and promote transhipment,reduce its accumulation in leaf,eventually increase the skin pigment content,make the skin red,significantly and improve the fruit soluble solid content,lower titratable acid content,to improve the quality of the fruit external and internal.4.Using the principal component analysis(pca)for different processing magnesium deficiency grape physiology and quality index of comprehensive evaluation,the score obtained from high to low in turn is:S10F0.4>S10F0.2>S12.5F0>S10F0>S7.5F0.4>S12.5F0.2>S0F0.4>S7.5F0.2>S7.5F0>S0F0.2>S12.5F0.4>S0F0,show that the magnesium deficiency grapes using land was 10 kg/667m2 foliar spraying 0.4%magnesium sulfate fertilizer at the same time,the index the best grapes,must lose production line is suitable for using this match with the lack of conditions similar to the vineyard magnesium magnesium vineyard.