Study On The Main Affecting Factors Of Square Budding Of Grafting Survival Of Walnut

Walnut has very high economical value and is propagated by grafting in most cases.Square grafting was developed from late in 20'90 and it was the easiest grafting methodapplied in field. In order to enhance the square budding survival rate, the affecting factorsand the mechanism of grafting survival were studied in field. The results were as follows:1. The effects of bud in different position on cion on the square budding survival andgrafted seedlings growth were studied. The results showed that on the grafted date of Maythe 29th,June the 5th and June the 12th in 2005, the survival rates of the middle bud on thescion were the highest, and the value were 97.9%,97.1% and 97.5%; next were the upperbud on the scion, and the value were 92.6%,94.2% and 91.8%; the lowest were the lowerbud on the scion, and the value were90.5%,90.1% and 89.3%. The trend of graftingsurvival rates in 2006 were the same as that of in 2005. The effects of bud in differentposition on cion to growth after square budding showed that 10 days after the grafted dateof May the 29th in 2005, the non-sprouting ratio in the total grafted seedlings of the lowerposition,upper position and middle position buds on cion were 54.32%,42.80% and39.92%; 15 days after the grafted date of May the 29th in 2005, the sprouting ratio in thetotal grafted seedlings of the lower position,upper position and middle position buds oncion were39.09%,39.51% and 57.20%; 20 days after the grafted date of May the 29th in2005, the basseting-bud ratio in the total grafted seedlings of the lower position,upperposition and middle position buds on cion were 36.63%,44.03% and 51.03%. 10 days afterthe grafted date of June the 5th in 2005, the non-sprouting ratio in the total graftedseedlings of the lower position,upper position and middle position buds on cion were43.21%,39.09% and 45.68%; 15 days after the grafted date of June the 5th in 2005, thesprouting ratio in the total grafted seedlings of the lower position,upper position andmiddle position buds on cion were 41.98%,44.86% and 34.57%; 20 days after the grafteddate of June the 5th in 2005, the basseting-bud ratio in the total grafted seedlings of thelower position,upper position and middle position buds on cion were 32.92%,33.74% and33.33%. 10 days after the grafted date of June the 12th in 2005, the non-sprouting ratio inthe total grafted seedlings of the lower position,upper position and middle position budson cion were 44.44%,49.79% and 48.97%; 15 days after the grafted date of June the 12th in 2005, the sprouting ratio in the total grafted seedlings of the lower position,upperposition and middle position buds on cion were 45.68%,45.67%and 46.91%; 20 days afterthe grafted date of June the 12th in 2005, the basseting-bud ratio in the total graftedseedlings of the lower position,upper position and middle position buds on cion were36.63%,34.57% and 39.51%. The growth trends of seedlings from grafting to survival ofdifferent position and different time in 2006 had the same trends with that of in 2005,which were grafted with the middle bud grew the fastest, next was the upper bud, andgrafted with the lower bud grew the slowest. The growth conditions of the seedlingsgrafted with different position buds on cion and at different time showed that: on thegrafted date of May the 29th,June the 5th and June the 12th in 2005, seedlings grafted withthe middle bud grew fast, the seedlings diameters were 1.232cm,1.174cm and 1.123cm,and the seedlings heights were 90.0cm,72.6cm and 55.3cm; next were grafted with thelower bud, the seedlings diameters were 1.125cm,1.008cm and 0.984cm, the seedlingsheights were 76.5cm,54.7cm and 50.6cm; seedlings grafted with the upper bud grewslowly, the seedlings diameters were 1.078cm,0.972cm and 0.962cm, the seedlings heightswere 72.6cm,51.5cm and 48.5cm. The growth conditions of the seedlings grafted in 2006had the same trend with that of 2005.2. The effects of contents of endogenous hormones in different position on cion on thesquare budding survival and grafted seedlings growth after survival were studied. Theresults showed that there existed very significant positive correlation between the ratios ofIAA/GA₃,IAA/ABA in bud and the square budding survival rate, the correlationcoefficients were 0.9910 and 0.9972; there existed significant positive correlation betweenthe content of IAA,the ratio of ZT/ABA in bud and the square budding survival rate, thecorrelation coefficients were 0.9757 and 0.9500. There existed significant positivecorrelation between the contents of IAA,ZT,the ratio of ZT/ABA in bud and the diameterof grafted seedlings after survival, the correlation coefficients were 0.9521,0.9750 and0.9774. There existed very significant positive correlation between the content of ZT andthe height of grafted seedlings after survival, the correlation coefficient was 0.9995; thereexisted significant negative correlation between the ratio of GA₃/ZT and the height ofgrafted seedlings after survival, the correlation coefficient was -0.955 4.3. The effects of contents of main mineral elements in different position on cion on thesquare budding survival and grafted seedlings growth after survival were studied. Theresults showed that there existed no significant correlations between the contents ofdifferent kinds in bud and the square budding survival rate; there existed very significantnegative correlation between the ratio of Mg/N in bud and the square budding survival rate,the correlation coefficient was -0.9940; there existed significant positive correlationbetween the ratio of Ca/Cu,Fe/Mn,Zn/Cu in bud and the square budding survivalrate, thecorrelation coefficients were0.9867,0.9518 and 0.9724. There existed very significant positive correlations between the content of Zn,the ratio of N/P in bud and the diameter ofgrafted seedlings after survival, the correlation coefficients were 0.9988 and 0.9958; thereexisted significant positive correlation between the content of Ca, the ratio of Fe/Mn in budand the diameter of grafted seedlings after survival, the correlation coefficients were0.9829 and 0.9717. There existed very significant positive correlation between the contentof Ca in bud and the height of grafted seedlings after survival, the correlation coefficientwas 0.9987; there existed significant positive correlation between the content of Zn, theratio of N/P,N/K,Fe/Mg in bud and the height of grafted seedlings after survival, thecorrelation coefficients were 0.9816,0.9667,0.9599 and 0.9825.