High density cultivation techniques of Xingao Pear

High Density Cultivation Techniques of Niitaka Pear

Niitaka pear originated in Japan and belongs to sand pear family. In March 2010, Xingao pear was introduced from Jiyang County, Shandong Province and planted in Zhangjia Village, Sun Town, Zouping County. The soil thickness was more than 80cm and the soil pH value was 7.1~7.2. The annual average temperature is 13.8℃, and the temperature difference between day and night in autumn is greater than 10℃. After 8 years of cultivation observation shows that the new height pear posture half-open, strong tree vigor, more upright, strong branches. Germination force is high, branching force is weak, easy to form short fruit branches. Young trees have strong fruit bearing ability on long, medium and short fruit branches, and mature trees mainly bear fruit on short fruit branches [1, 2]. Flower buds germinate in the middle of March, pollen is few, need to configure pollination tree. The fruit ripens in mid-September, and the fruit is nearly round and golden yellow (Figure 1).

Fig. 1 Fruiting state of Niitaka pear

The fruit weighs 500~1500g. Thin skin and small core, tender and juicy flesh, fructose content 15%~17%, edible pulp rate 95%. Stone cells are very few, taste excellent, high yield and stability. The fruit has extremely high antioxidant properties, and the profile does not change color or deteriorate for ten days. Storage resistance, indoor natural conditions can be stored for 3 months, cellars for 6 months, thermostat can be refrigerated for one year [3]. At present, modern high-density planting, net frame and labor-saving cultivation mode are adopted, with planting area of 53.3hm2(more than 800 mu) and annual output of 2 million kg. The new high pear is sold to more than 20 provinces, cities and autonomous regions in China. The cultivation techniques are described below.

1 Garden planting

High density planting, net frame (V shape), labor-saving cultivation mode, plant spacing 0.65m× 3m, plant design planting height 2.5m(Figure 2). It should be planted in spring and deep ploughed in autumn of last year. Dig holes for planting, with length, width and depth of 1m respectively. or planting ditches 0.6m wide and 0.6m deep. The excavated topsoil and subsoil are separated, and 15~25kg soil fertilizer and 3~5kg fruit tree fertilizer are applied to each plant when backfilling. Select high-quality seedlings for planting. Yellow pollinated trees were arranged in the garden, and the planting ratio of main varieties to pollinated trees was 5:1.

Fig. 2 V-shaped grid of pear garden

2 Soil and fertilizer management

Basic fertilizer is applied in autumn, 1500kg is applied to trees in early fruit stage and 4500kg is applied to trees in full fruit stage every 666.7 m2. Basic fertilizer is generally chicken manure, crop straw, human manure and other organic fertilizers.

Topdressing is carried out 4 times a year, namely before flower bud germination (middle and late March to early April), flower bud differentiation period (June to August), fruit expansion period (July to August) and after fruit picking (September to October). When topdressing, pay attention to applying phosphorus and potassium fertilizer according to the fertilizer requirement law of pear trees, and supplement nitrogen fertilizer before wheat harvest (June). Apply phosphorus and potassium fertilizer in the middle growth period of pear trees, apply potassium fertilizer before fruit harvest, and apply nitrogen fertilizer and base fertilizer after harvest to ensure tree nutrition and lay a good foundation for next year's harvest (Figure 3). Antifreeze water can be poured once a year before flowering, watering at the flower bud differentiation period before the end of June, keeping the water required for fruit expansion and preventing fruit drop. Chilled water is poured in time after fruit harvest. Every time the water is fully watered, if it encounters continuous dry weather, it can be watered again.

Fig. 3 Fertilization and watering of new high pear orchard

3. Shaping and pruning

Free spindle shape and modified spindle shape should be adopted for young trees. After the stem is fixed, the branches are picked (from late May to early June) to promote the fruiting branches. Young trees stay more main branches, more short cut to promote branches, autumn branch open angle. To be less thinning and more cutting, vertical vigorous branches flat use, pull 70°~80° before the end of June, thinning out competitive branches, excessive long branches, back branches, cross branches, middle trunk appropriately cut short, the rest of the branches as far as possible light cutting or slow release, in order to increase the number of branches and leaves. For the culture of fruiting branch group, the method of expanding first and then contracting was adopted. When entering the peak fruiting period, pay attention to the timely renewal of branch groups and the use of young fruit branches to keep the vigorous tree vigor. Short fruit shoot groups should be cultivated on the backbone branches at all levels, and they should be renewed and rejuvenated every year, weak branches and weak buds should be thinned out, and more fruit branches should be retained. Pruning is mainly carried out in the growth period, mainly in summer; pruning is supplemented in the dormant period, mainly in thinning branches, and tree shape is adjusted. Pay attention to the protection, cultivation and utilization of the branches sprouting from the hidden buds in the crown.

4 Flower Management

Flowering and fruit management follows the principle of "first protect and then sparse". On the basis of pollinating trees, artificial pollination can be adopted, spraying 0.2% borax solution at flowering stage, spraying 20mg/L gibberellin, 0.1% urea and 0.2%~0.3% potassium dihydrogen phosphate mixture after flowering, or releasing bees in pear orchard. After pollination, flower thinning is carried out 2~3 weeks after flowering, overdense flowers, weak flowers, abnormal fruits, diseased fruits and young fruits are manually thinned, and the fruit spacing is adjusted to 15~20cm(Figure 4).

4. Flowers of Niitaka pear

5 Pest control

The main diseases of Niitaka pear were black spot, pear rust, black spot and ring spot, and the pests were pear psyllid, pear stem bee and pear yellow powder aphid. Pest prevention, integrated control, emphasis on physical control, biological control [4, 5]. 1. Using the physical and biological techniques of sticky insect board, sticky insect glue and releasing horn-fronted wall wasp to produce safe and high-quality pear fruits. Fruit bagging to prevent and control diseases and insect pests that harm fruits. Scrub the diseased skin before budding in early spring every year, spray carbendazim 100~150 times solution or 4~5°Be stone sulfur mixture after scraping, and eliminate the source of diseases and insect pests. In rainy years, when conidia are spread and infected in large quantities from May to July, carbendazim or 70% thiophanate-methyl 700~800 times solution can be sprayed once every half month, and lime excess Bordeaux mixture 200~240 times solution can be sprayed. According to rainfall and disease occurrence, the control should be carried out before flowering, after flowering, before fruit bagging and in rainy season.