Abstract:

【Objective】 Dwarfing effects and mineral elements content of the trees grafted on three dwarfing intermediate stocks S2, 82-5 and PDR54 were comparatively studied. That provided basis for the selection of inter-stocks in pear dwarfing culture. 【Method】 Different scions were grafted on S2, 82-5, and PDR54 (each has three different lengths) as inter-stock and P. betulaefolia Bge as rootstock. The growth and other indexes of grafting trees were measured. 【Result】 All of the S2, 82-5, and PDR54 had remarkable dwarfing effect. The dwarfing effect was enhanced when the intermediate stock was longer, but not with equal proportion. The dwarfing effect reached the maximum when the length of the inlermediate stock was 10 cm. The content of mineral elements in leaves of the trees grafted on the three intermediate stock was significantly different from the control. The content of N, Ca, Mg and Fe in the leaves grafted on S2 and 82-5 all showed an increasing trend and the content of Fe increased by 66.5% and 53.6%, respectively. But the content of mineral elements decreased in some degree on PDR54. 【Conclusion】 All of the S2, 82-5, and PDR54 had remarkable dwarfing effect, and the effect from strong to weak were PDR54＞82-5＞ S2. The effect will reach the maximum when the length of the intermediate stock is 10 cm. As the dwarfing intermediate stock, S2 and 82-5 could promote the grafting tree to absorb mineral elements, especially for Fe, but PDR54 had the contrary function, so fertilizer application is needed for improvement.

Key words: pear, dwarfing stock, dwarfing culture, dwarfing effect, mineral elements