Abstract:

Under desirable growing conditions, the amounts of shoots removed during winter pruning should be 40% or so with 6-year-old Xueqing pears. After winter pruning, 216.7 shoots per tree was averagely left with 121.3 bearing shoots. And the rate of growing shoots to bearing shoots was 1:1.3. The number of average clusters remained was 207.7 per tree and 85.3 fruits were eventually left after thinning. The yield of 26.4kg/tree was obtained at harvest, which attained the requirement of higher yield according to the current standard for young pear plantings. Simultaneously, 47.1% bearing shoots formed, which could absolutely meet the bearing need for next year. By applying the present pruning severity, the shoot regenerating rate reached 61.4% and the proportion of shoots to a fruit became 4.1:1. Winter pruning could alter the composition of different types of shoots. For example, the percentage of long-shoots, medium-shoots and spurs was 24.8%, 14.9% and 59.9%, respectively, prior to pruning treatment, but the rate changed to 15.7%, 18.2% and 66.2%, respectively, after winter pruning by removing 61.6% long-shoots, 16.0% medium-shoots and 33.0% spurs. However, after a growing season, the percentage was restored to 25.0%, 13.8% and 60.7%, respectively, which was almost the same as that one year ago before winter pruning. By means of this pruning method, the total shoot amounts of two years before winter pruning were approximately the same, indicating that the pruning severity was appropriate for sake of the relative balance between growing and bearing of young pear trees.