Effects Of The Pyrus Betulaefolia Nontransplanted And Transplanted Rootstocks On Growth Of Pear Seedlings And Analysis Of The Effect Of Notching-bud On The Trunk

Building pear orchard with high-quality seedlings and increasing the quantity of branch and leaf were important factors to achieve good harvest in early time. Taking the two years old Pyrus betulaefolia rootstock and one year old pear seedlings as test materials, adopting the method of the field investigation and conducting the influence of nontransplanted Pyrus betulaefolia and transplanted rootstock on the seedling growth and the effect of notching-bud on the branching ability of the central trunk,which was mainly to the question of the general low-quality nursery-grown plants in the tree production. It aimed at comparing the differences of scions growth regularity grafted on these two types of rootstocks and revealing the relationship between the branching rate of central trunks and the branches growth after bud- notching. The main results are as followings:1. Compared with the transplanted rootstock, nontransplanted rootstock can promote the growth of cions, That was mainly shown in three aspects: the short time needed to germinate for scions; rapid growth of scions in early stage; the short time needed to enter the slow growth period. scions grafting on transplanted rootstock had no obvious effect on promoting scions growth after stumped.2. The growth of scions in the grafting year and after stumping had significant differences. The heights of Yali and Whangkeumbae seedlings after stumped increased by 35.44 cm and 44.29 cm respectively, and the stem diameters increased by 3.83 mm and 3.83 mm respectively.3. The Pyrus betulaefolia rootstocks with different diameters had different influences on scions, which were mainly reflected that the thicker the rootstock was, the stronger the scion’s vigor is. The amount of growth of Yali and Whangkeumbae seedlings had no significant difference when the stem diameter of Pyrus betulaefolia rootstocks were 8-10 mm,10-12 mm and 12-14 mm. The amount of growth of Xinli No.7 seedlings grafted onto the rootstocks whose stem diameter were 14-16 mm was significantly higher than that grafted onto the rootstocks whose stem diameter were 8-10 mm.4. The number of lateral root had a significant impact on the Xinli No.7 scions. The amount of growth of Xinli No.7 grafted onto the rootstocks with more 4 lateral roots was higher than that grafted onto the rootstocks with 1 or 2~3 lateral roots, but the differences were not significant.5. For Xueqing, Whangkeumbae and Crispy Red pear seedlings, the branching rates of the central trunks with bud-notching or not bud-notching had significant differences. the branching rate of these three varities with bud-notching increased by 9.74%, 6.16% and 9.74% respectively.6. Bud-notching changed the proportion of branch sorts of the central trunks. For Xueqing, Whangkeumbae and Crispy Red,these three varieties with bud-notching, the long shoot rates increased by 30.4%, 18.45% and 14.48% respectively and short shoot rates was reduced by 21%, 33.15% and 2.33% respectively. For Xueqing pear and Whangkeumbae, the amounts of growth of long shoot decreased by 16.78 cm and 7.8 cm respectively.7.For Xueqing pear and Whangkeumbae seedlings with bud-notching or not bud-notching, the numbers of flower buds had significant differences. The total number of flower buds of these varieties increased by 11.46 and 7.62 respectively. For Xueqing pear seedling,the number of flower buds of long branches increased by 10.29.For Whangkeumbae seedling, the number of flower buds of medium sticks increased by 6.03.