How does 'Lübaoshi' pear perform in Zunhua, Hebei?
The 'Lübaoshi' pear was bred by the Zhengzhou Fruit Research Institute of the Chinese Academy of Agricultural Sciences by crossing 'Xinshiji' with 'Zaosu'. Zunhua City introduced the 'Lübaoshi' pear from the Zhengzhou Fruit Research Institute in 2003. Top-grafting was carried out in Xiafu Village, Xisanli Township, and the cultivar grafted over was 6-year-old 'Yantai' pear.
1. Test orchard conditions and management. The soil of the top-grafted orchard is sandy loam, with irrigation available. The level of management is moderate. In spring, bud grafting with wood was used, adopting multi-branch top-grafting, and the trees were in good condition at that time. The top-grafted 'Lübaoshi' pear occupied 1 row, 32 trees in total, and the grafting survival rate reached 97.7%. After the grafts survived, suckers were removed in time; when the new shoots were about 40 cm long, the ties were untied and support sticks were attached, and after the new shoots became woody, the support sticks were removed. Each year after autumn or in spring, 2000-3000 kg of organic fertilizer was applied; fertilizer was top-dressed before bud break and during the rapid fruit enlargement stage. Before bud break, nitrogen fertilizer was the main type; for trees in full fruiting stage, 25-30 kg of urea was applied per mu, and during the fruit enlargement stage, pear tree special fertilizer was applied. Trees in full fruiting stage were given 100-150 kg per mu. Irrigation was carried out together with fertilization. Bagging was done in mid-to-late May for consecutive years; before bagging, one spray of 70% thiophanate-methyl 1000 times + 80% Dacotech M45 800 times + 10% imidacloprid 500 times was applied. Fruit spacing was 20-25 cm, and fruits were picked with the bags on. Winter pruning was relatively light, mainly by heading back, with very little thinning of branches; summer pruning used methods such as branch bending and bud notching. Each year before bud break, 3-5°Be lime sulfur mixture was sprayed, and timely sprays of 20% imidacloprid 3000 times were used to control aphids, 10% polyoxin 1000 times to control black spot, and 20% diflubenzuron No. 3 2000 times to control fruit borers and other pests and diseases.
2. Growth, fruiting characteristics and resistance
(1) Growth characteristics. Through observation, the 'Lübaoshi' pear has strong branching ability; by adopting light pruning and long-shoot laying, the canopy of the top-grafted trees formed rapidly, and the orchard appearance was neat. After long shoots were laid down, they could all sprout into short shoots and short fruit spurs, with very few medium and long shoots, and the flower formation rate reached more than 90%.
(2) Early fruiting and high yield. The 'Lübaoshi' pear began to bear fruit in the 2nd year after grafting, with an average yield of 13.5 kg per tree; in the 3rd year after grafting, the average yield was 34.3 kg per tree, equivalent to 1926.4 kg per mu. In the 5th year after grafting, the average yield was 50.3 kg per tree, equivalent to 2816.8 kg per mu. It can be said that the 'Lübaoshi' pear has very strong early fruiting and high-yield performance.
(3) Fruit traits. In a random survey in 2006, the average single fruit weight of 'Lübaoshi' was 268 g. The largest was 402 g. Bagged fruit had a regular shape, smooth skin, relatively obvious lenticels, a yellow-green ground color, and some calyxes persisted. Fruit firmness was 8.7 kg per square cm, the flesh was white, delicate, sweet and juicy, crisp and tasty, and the soluble sugar content was 12.7%. The overall quality was superior.
(4) Phenological period. After years of observation, in Zunhua, the 'Lübaoshi' pear buds in mid-March, reaches full bloom in mid-April, with a flowering period of about 10 days, enters the fruit enlargement stage in late June, and the fruit ripens in early August.
(5) Resistance. Over several years, the 'Lübaoshi' pear did not develop pear scab or pear psylla, and only slight aphid occurrence occurred; after spraying imidacloprid, good control results were achieved. In some years, black spot and fruit borers occurred, but all were controlled in time.
In summary, the 'Lübaoshi' pear performs well in Zunhua, with fast tree growth, strong early fruiting and high-yield performance, large fruit size, and relatively strong resistance to pests and diseases. It is an excellent early-maturing, large-fruited variety worthy of vigorous promotion.