Effects Of Application Of Calcium,Magnesium And Boron Fertilizers On Leaf Etiolation,Fruit Quality Of Citrus Paradisi Cv.Changshanhuyou For Two Consecutive Years

Using Zhejiang Changshan County endemic species "Changshanhuyou"(Citrus paradise cv.Changshanhuyou) as materials,this study would charified the effects of application of Calcium,Magnesium and Boron fertilizers on restoring of leaf etiolation and fruit quality by field trial.The main conclusions obtained are as follows:1. Applying Ca、Mg and B fertilizers would increase the production of Citrus paradisi cv.Changshanhuyou,resulting in increased yields with8.1%-43.7%.and co-operation Ca、 Mg and B had the best effect.Following was co-operation Ca and Mg.2.1n the growth stage of Citrus paradisi cv.Changshanhuyou,single or both application of Ca and Mg,and three of them had the apositive effect on the relative value of chlorophyll,and juring the treatments both of Ca and Mg had the best results.and following are three of them.3.Correlation analysis showed that magnesium contents in mature leaves (harvest stage) had extremely significant linear correlation,with relative chlorophyll content(SPAD values).with linear equation was y=131.5+57.32x,R2=0.777.Magnesium deficiency was the main factors causing leaf etiolation in Citrus paradisi cv. Changshanhuyou.4. Single or mixed application of calcium,magnesium and boron fertilizers could improve Citrus paradisi cv.Changshanhuyou juice content with the range of3%-8%;single application of calcium,magnesium,boron fertilizers or mixed application of calcium,magnesium could significantly increase fruit soluble solids content;single or mixed application of Calcium,magnesium,boron fertilizers also increased Vc content with the range of3.5%-17.6%, and single application magnesium was best,following was mixed application of magnesium,boron.5. Calcium and magnesium boron application for two consecutive years could improve soil pH about0.8pH, showing applying lime fertilizer could sameliorated soil acidification,However,the pH in grapefruit garden soil didn’t changly greatly,it menat we should increased the application amounts of calcium fertilizers to make it chang more.6. Application of calcium and magnesium,calcium magnesium boron fertilizers significantly increased the yield with22.5%and43.7%respectively,but also decreased greatly organic matter content of soil;and organic matter content of soil in2012was significantly lower than that in2011,indicating we should add organic fertilizers to maintain soil fertility levels in Citrus paradisi cv.Changshanhuyou orchard.7. During the growth cycle of Citrus paradisi cv.Changshanhuyou,single or mixed application of calcium, magnesium,boron fertilizers all could increase soil available nitrogen content,but soil available nitrogen content in2012was significantly lower than in2011,indicating that should add nitrogen fertilizers to meet soil normal consumption and plant demend. Single or mixed application of calcium,magnesium,boron fertilizers and balanced fertilization both could increase soil available phosphorus content,with the best effect were the two treatments of calcium+magnesium,and magnesium+boron. Compared to conventional fertilization,single application of calcium,magnesium,boron and magnesium,mixed application of calcium and magnesium,magnesium and boron all could increased soil available potassium content.8. Mixed application of Magnesium fertilizer could improve soil available calcium, with the best effect was the treatment of calcium,magnesium,boron;and also increased the content of soil available magnesium,applying magnesium fertilizer for two consecutive years in the soil effectively restored soil magnesium content to appropriate level;calcium and magnesium boron with which the effect of applying the most obvious;mixed application of boron and magnesium fertilizers promoted soil available boron content, single and mixed of boron fertilizers for two consecutive years both significantly increased soil available boron content.